ISSN 0970-0137

Current Issue

April – May 2021 issue, Vol. 48 No. 1

 
48-T2

Issue: April – May 2020, Vol. 48 No. 1

A high-performance geopolymer concrete an experimental study using fly ash, GGBS and copper slag

S. Imran Khan, Getnet Tadesse Abegaz and Biftu Jaleta
71
48-T2

Issue: April – May 2020, Vol. 48 No. 1

A high-performance geopolymer concrete an experimental study using fly ash, GGBS and copper slag

S. Imran Khan, Getnet Tadesse Abegaz and Biftu Jaleta
71

The research on an experimental investigation of fly ash-GGBS Based with high performance geopolymer concrete is done with an exclusive vision of not only to endeavor in the pursuit of reducing Global Warming on the earth and CO2 emission, but also for saving the earth from being affected by environmental pollution due to industrial waste. Geopolymer Concrete is used as an alternate for cement and M sand by a composition of Alkaline Activator Solutions (AAS) and Copper Slag (CS). To produce High Performance Geopolymer Concrete (HPGC), an experimental test was conducted by means of 11 (eleven) different mixing proportions with the replacement of binder material fly ash by Ground Granulated Blast of Furnace Slag (GGBS) with a proportion from 0% to 100% by weight at an increment of 10% with M sand as filler materials. Towards attaining the next stage of polymerization, Alkaline activator solutions (14 molar Sodium Hydroxide and Sodium Silicate) were used in this trail test and researched for polymerization. To adopt different mixing proportions, the specimen was cast and heat curing was done by maintaining 70 degree Celsius for 24 hours. The strength parameters of concrete such as compressive strength, split tensile strength and flexural strength were tested on the specimen. The test results show that the combination of 60% GGBS and 40% fly ash has produced high compressive strength of 71.70 N/mm2. Another trail test was made with the same proportion of binder material and the filler material of M sand is replaced with Copper slag from 0% to 100% by weight at an increment of 10%. By adopting eleven different mixing proportions, the result indicates that the substitution of 50% copper slag by M sand has yielded high compressive strength of 80.30 N/mm2. The HPGC has thus resulted by the above mixing combinations.

48-T1

Issue: April – May 2020, Vol. 48 No. 1

Retrofitting of room temperature (K-130) cyclotron building in VECC Kolkata using composite beam...

Soubhagya Karmakar, Amit Singh, Saha Dauji, Satish Kumar Saini and Pratap Kumar Panda
61
48-T1

Issue: April – May 2020, Vol. 48 No. 1

Retrofitting of room temperature (K-130) cyclotron building in VECC Kolkata using composite beam...

Soubhagya Karmakar, Amit Singh, Saha Dauji, Satish Kumar Saini and Pratap Kumar Panda
61

K-130, a Room temperature cyclotron building is one of the essential facilities in Variable Energy Cyclotron Centre (VECC), Kolkata, used mainly for research and development. Due to expansion of facilities a requirement was raised by the Radioactive Ion Beam Development Division (RIBD), VECC to test the electron Linac (e-Linac) injector in HR cave-1, which was the only shielded area for same machine. This in turn led to increase structural demand. Therefore, to facilitate the system and keeping the structural integrity intact, a demand reduction approach has been adopted without much changes in the dynamic properties of the structure. This paper brings out a retrofitting scheme with the introduction of composite beam concept in an existing structure to meet the demand of increase in superimposed dead load. Seismic feasibility of the structure has been concluded based on an indirect approach. Further, arrangements have also been shown to take care of the stress concentrations and ensure safe load transfer near cut-outs.

48-06

Issue: April – May 2020, Vol. 48 No. 1

Stiffness maximization of concrete structures using topology optimization in static and dynamic...

V.R. Resmy, and C. Rajasekaran
51
48-06

Issue: April – May 2020, Vol. 48 No. 1

Stiffness maximization of concrete structures using topology optimization in static and dynamic...

V.R. Resmy, and C. Rajasekaran
51

This study highlights the generation of truss-like patterns for Strut and Tie Modeling (STM) using bidirectional evolutionary topology optimization in concrete structures. STM is an effective approach for the design of Discontinuity regions (D-regions) where standard Bernoulli’s hypothesis cannot be applied. As the conventional methods of STM generally follow a trial and error procedure, the final solution may not be unique. Topology optimization is classified under structural optimization to find the effective layout of structure based on the load path method. It is a scientific method that relies on structural mechanics; the inaccuracies related to STM can be avoided with the aid of topology optimization. In static problems, minimizing compliance leads to reasonably more stiff structures. In free vibration problems, the maximization of eigen frequency can be taken as an objective to get the maximum stiff structure. Solid Isotropic Material with Penalization (SIMP) material model assumes a constant and isotropic material properties in each discretized rectangular element. Evolutionary optimization derives the optimum structural layout by removing the ineffective elements and adding the effective elements in subsequent iterations. Method of Moving Asymptotes (MMA) developed by Svanberg (1997) is a kind of convex approximation has also been implemented in static problems.

48-05

Issue: April – May 2020, Vol. 48 No. 1

A case study on performance and ductility behaviour of splice connection in steel structures

V. Ramana Kollipara, and T.D. Gunneswara Rao
41
48-05

Issue: April – May 2020, Vol. 48 No. 1

A case study on performance and ductility behaviour of splice connection in steel structures

V. Ramana Kollipara, and T.D. Gunneswara Rao
41

In most cases, the local failure of the connection in a steel framed structure affects the serviceability criteria of the entire structure. Hence, it is necessary to study and understand the behaviour and failure mechanisms of connections used in steel framed structures. In view of this, the paper describes the experimental, theoretical and numerical investigations conducted on the bolted moment end plate splice connection joining Hollow Tubular Sections (HTS). In this study, a four-bolt end plate connection configuration is adopted for the fabrication of splice connection, and also a parametric variation of the dimensional properties of the connection components such as thickness of end plate, diameter of bolt, and thickness of HTS member is considered. In the theoretical analysis, using the stub tee analogy method new design equations are predicted to compute the ultimate moment capacity of the proposed splice connection. In the numerical analysis, the behaviour of end plate splice connection (with the parametric variation) is studied using finite element package ANSYS in detail. Finally, a comparative study is done between the obtained results of theoretical, numerical with the experimental results to validate the accuracy of predicted design equations and the proposed numerical model.

48-04

Issue: April – May 2020, Vol. 48 No. 1

Finite element analysis and design of steel corner gusset plates with double row of bolts for net...

K.S. Vivek, K.S. Sai Ram and R. Baskar
32
48-04

Issue: April – May 2020, Vol. 48 No. 1

Finite element analysis and design of steel corner gusset plates with double row of bolts for net...

K.S. Vivek, K.S. Sai Ram and R. Baskar
32

Gusset plates are subjected to complex stresses and obtaining the design thickness is not straight forward as the stresses depend upon the thickness of gusset itself. In this study, a typical case of a corner gusset plate connected to tension member (bracing / diagonal) in a braced frame or a truss girder bridge is considered. It is assumed that the gusset plate is welded at the beam-column joint in a braced frame or at corner joint of a truss girder bridge and connected to the tension member by bolts in double row. Simple 2-D model of gusset plate is developed and non-linear finite element analysis is carried out with the help of ANSYS, a commercial finite element software, for varying load magnitudes. Four, six and eight bolt cases are analyzed. On performing several trails the required thickness of gusset to prevent net section rupture as per the non-linear analysis is noted based on the obtained von-Mises stresses and plastic strains for all the cases. Later the required thicknesses of gusset plates as per Whitmore’s theory and Indian, European, American and Canadian codes of practice are also calculated. Significant discrepancy was noted between the results of finite element analysis, Whitmore’s theory and the various codes of practice considered in this study. On examining the obtained results, probable design thicknesses of gusset plates are proposed for each case. The presented design thicknesses may be useful as a reference / guide for design engineers in fixing the initial thickness of gusset plate to prevent ‘net section rupture’.

48-03

Issue: April – May 2020, Vol. 48 No. 1

Study of reinforced concrete circular column crack control and modifcation in P-M interaction...

R. Eswaran and S. Sivakumar
24
48-03

Issue: April – May 2020, Vol. 48 No. 1

Study of reinforced concrete circular column crack control and modifcation in P-M interaction...

R. Eswaran and S. Sivakumar
24

This paper presents the study of design methods for checking of Reinforced Cement Concrete (RCC) circular columns crack width control. The various case studies of design explain the importance of crack width control in addition to design for limit state of collapse ie., strength requirements. In the beginning, this paper explains the cases for which the higher area of reinforcement is required for crack width control than the requirement for strength aspect. The sample design calculation for crack width checking is also presented. Next, this paper explains the safe zone in P-M interaction curve as per SP-16 of Indian standards, where the circular sections are safe in both strength as well as crack width control requirements. The unsafe zone in P-M interaction curve describes the circular sections are safe as per strength but unsafe as per crack width control requirements. Finally the method for modification of P-M interaction curve in unsafe zone is explained by increasing the percentage of reinforcement to satisfy the crack width control. The modified design charts for calculating area of reinforcement required are presented. These modified design charts provide guidance to the structural designer while designing for limit state of serviceability for RCC circular columns.

48-02

Issue: April – May 2020, Vol. 48 No. 1

Study on elastic constants of polymer modified steel fibre reinforced high strength concrete with...

Praphulla K. Deshpande, Keshav K. Sangle and Yuwaraj M. Ghugal
12
48-02

Issue: April – May 2020, Vol. 48 No. 1

Study on elastic constants of polymer modified steel fibre reinforced high strength concrete with...

Praphulla K. Deshpande, Keshav K. Sangle and Yuwaraj M. Ghugal
12

The paper deals with the experimental and theoretical results of elastic constants of polymer modified high strength concrete with high fibre volume fraction. To evaluate elastic properties of this composite system, compressive strength, flexural strength, shear strength and corresponding load deformation responses were examined experimentally. Elastic properties such as modulus of elasticity, shear modulus and Poisson’s ratio are first obtained based on experimental results. Simplified equations based on micromechanics, and solid mechanics theories are utilized for the evaluation of elastic properties of polymer modified randomly oriented short steel fibre reinforced high strength concrete. The micromechanics equations for the modulus of elasticity, the shear modulus and the Poisson’s ratio are based on the fibre volume fraction and the elastic moduli of the fibre and polymer modified concrete matrix. The existing empirical equations are also used to obtain elastic constants. These equations are applied in the full range of fiber volume fraction (1% to 10%). The comparison of experimental results with theoretical values shows the good agreement with each other. The novelty of the present paper is that the modulus of elasticity of this composite system is obtained experimentally using four point bending test and the Poisson’s ratio is obtained as a function of flexural and compressive strengths with sufficient accuracy.

48-01

Issue: April – May 2020, Vol. 48 No. 1

Compressive strength prediction of SCC containing fly ash using SVM and PSO-SVM models

R. Rajeshwari, Sukomal Mandal and C. Rajasekaran
01
48-01

Issue: April – May 2020, Vol. 48 No. 1

Compressive strength prediction of SCC containing fly ash using SVM and PSO-SVM models

R. Rajeshwari, Sukomal Mandal and C. Rajasekaran
01

Self-Compacting Concrete (SCC), is a highly workable material, compacted by its self weight without observable segregation and bleeding. In this study, Support Vector Machine (SVM) and particle swarm optimization based SVM models are employed to predict the 28 days compressive strength of individual SCC mix. A database of 62 no’s of SCC compressive strength from literature with cement partially replaced by fly ash is used for training the models. The test data consists of two groups, an individual study consisting of 9 datasets and other combination of three studies with 19 datasets tested separately. Similar input parameters from the train data is extended for testing the models prediction accuracy. Statistical parameters such as correlation coefficient, root mean square error and scatter index are used to evaluate the models’ prediction results. The particle swarm optimization based SVM model is capable of selecting appropriate SVM parameters to increase the prediction accuracy. From the results, it is seen that both SVM and particle swarm optimized SVM models have good capability in predicting the SCC compressive strength.

47-43

February – March 2021, Vol.47 No. 6

Seismic safety evaluation of URM buildings through incremental dynamic analysis

S.R. Vaidehi, P. Kamatchi,, S.R. Balasubramanian and Girish Joshi
532
47-43

February – March 2021, Vol.47 No. 6

Seismic safety evaluation of URM buildings through incremental dynamic analysis

S.R. Vaidehi, P. Kamatchi,, S.R. Balasubramanian and Girish Joshi
532

The complexity in modeling Un-Reinforced Masonry (URM) buildings to understand their behaviour under seismic loading has been recognised in literature. The main objective of this study is to identify a methodology for quantification of seismic safety of URM building through incremental dynamic analysis. Prathmic Swasthya Kendra a single storey hospital building constructed in 1960 located at Uttarakhand, India, has been considered for this study. In the present study, equivalent frame modeling procedure for URM building has been adopted. User-defined shear hinge and flexural hinge properties are developed and are used in the analysis. Fragility curves are developed for the URM building from the incremental dynamic analysis, wherein, uncertainty in the characteristics of earthquake time histories are accounted by the use of suite of far-field ground motions. Fragility curves for different performance levels similar to that of. Immediate Occupancy (IO), Life Safety (LS) and Collapse Prevention (CP) as specified in FEMA 356 (2000) have been developed and collapse margin ratio is estimated. Adjusted Collapse Margin Ratio (ACMR) has been evaluated and comparisons are made with the minimum acceptance criteria specified for collapse limit state. As a part of the methodology, response reduction factor (R) is obtained for the URM building and the comparison has been made with the respective specification for URM building specified in Indian seismic standard. The methodology proposed can be adopted for seismic safety evaluation of existing or new URM buildings.

47-42

February – March 2021, Vol. 47 No. 6

Seismic crack propagation process of roller compacted concrete (RCC) gravity dam-reservoir-foundation...

Birhane Gebreyohannes Hagos, I. Siva Parvathi, and T.V. Praveen
519
47-42

February – March 2021, Vol. 47 No. 6

Seismic crack propagation process of roller compacted concrete (RCC) gravity dam-reservoir-foundation...

Birhane Gebreyohannes Hagos, I. Siva Parvathi, and T.V. Praveen
519

The seismic crack propagation in a typical Zoned Roller Compacted Concrete (ZRCC) gravity dam is modeled and analyzed by using extended finite element method (XFEM). The cracking process of Koyna dam due to 1967 Koyna earthquake is carried out considering the dam-reservoir-foundation interaction for validation of modeling process. Zoned Roller Compacted Concrete (ZRCC) gravity dam, viz., Gibe-III dam is considered to be a case study for the seismic crack propagation analysis. The dam is analyzed with different initial cracks at selected positions of the chosen ZRCC gravity dam by considering rigid and flexible foundation conditions. The effect of initial crack location on the crack propagation mechanism due to the seismic reaction is observed.

47-41

February – March 2021, Vol. 47 No. 6

Experimental and numerical investigations on response of a conventional framed tubular structure and a...

Minu Ann Peter, A.S. Sajith and Praveen Nagarajan
508
47-41

February – March 2021, Vol. 47 No. 6

Experimental and numerical investigations on response of a conventional framed tubular structure and a...

Minu Ann Peter, A.S. Sajith and Praveen Nagarajan
508

The paper investigates the behaviour of diagrid structures in comparison to conventional framed structures when subjected to earthquake ground motions. The work involves experimental study using a uniaxial shake table, on models fabricated in the laboratory, and numerical simulations of the same in ETABS. Scaled-down models of a four-storey structure mimicking a conventional framed building and a diagrid building are used and linear time history analyses for different earthquake ground motion are performed. The results of the experimental studies indicate that the diagrid model performs in a better way compared to the conventional framed structure in terms of storey drifts, top storey accelerations and displacements. Substantial reduction in the top storey displacement is observed by employing diagrids. A pushover analysis performed towards the end shows the necessity to conduct nonlinear analysis to ensure the stability and ductility of the diagrid structure.

47-40

February – March 2021, Vol. 47 No. 6

The sensitivity of the acoustic emissions to the stress field and steel reinforcement in beams under...

R. Vidya Sagar
495
47-40

February – March 2021, Vol. 47 No. 6

The sensitivity of the acoustic emissions to the stress field and steel reinforcement in beams under...

R. Vidya Sagar
495

An experimental study on the sensitivity of the Acoustic Emissions (AE) to the stress field and steel reinforcement in concrete beams is reported in this article. The Reinforced Concrete (RC) beam specimens were tested under a monotonically increasing load in the laboratory. Three large RC beams with shear reinforcement and another two large RC beams without shear reinforcement were tested. The aim is to study the sensitivity of the AE to the stress field and the steel reinforcement. Gaussian Mixture Modelling (GMM) algorithm of AE was implemented for the crack classification in the RC beams. Further, sifted b-values were used to improve the interpretation of the conventional b-value analysis. AE generated during tensile cracking and shear cracking were compared with the AE based sifted b-values for RC beams with shear reinforcement and RC beams without shear reinforcement. The AE based sifted b-values, which reflects the extent of the fracture process, decreased with the increase in mid-span deflection. When the generation of AE related to tensile cracks was less, the sifted b-values decreased gradually. In the shear failure beam, the AE related to shear cracks constituted a higher percentage of total hits, and sifted b-values sharply decreased. The observations may provide a reference for the studies related to AE testing of RC structural members.

47-39

February – March 2021, Vol. 47 No. 6

Progressive collapse of all-steel buckling restrained braced frames

P.C. Gopika Balagopal and B. Rajeevan
485
47-39

February – March 2021, Vol. 47 No. 6

Progressive collapse of all-steel buckling restrained braced frames

P.C. Gopika Balagopal and B. Rajeevan
485

A non-linear static pushdown analysis was used to evaluate the progressive collapse potential of all-steel Buckling Restrained Braced (BRB) frames. The frames were modelled using alternate path method in SAP2000®. In framed structures, adequate lateral resistance can be provided with steel braces. But, in seismic areas, these tend to buckle and exhibit reduced strength, stiffness, and resistance under periodic loading. All-steel BRBs are excellent in dissipating energy due to their high stiffness and ductility with reduced cross-sectional area. In this paper, a comparative study was performed to evaluate the improvement in energy dissipation of frames with ordinary concentric steel bracing and all-steel BRB. Firstly, frames with two different types of all-steel BRB obtained from literature were compared. Secondly, the effectiveness of all-steel buckling restrained braced frames under three bracing patterns, namely, double X, inverted V and hexa-bracing patterns were investigated. The progressive collapse potential was estimated from the variation of vertical deflection with the percentage of load. The ductility and support rotations were then determined from the estimated progressive collapse potential. These were then used as acceptance criteria for investigating progressive collapse as per General Service Administration (GSA) specifications.

47-38

February – March 2021, Vol. 47 No. 6

Fundamental strength properties of polymer concrete – effect of heating

Brajkishor Prasad, S. Ganesan, Prince Singh and Amit Kumar
475
47-38

February – March 2021, Vol. 47 No. 6

Fundamental strength properties of polymer concrete – effect of heating

Brajkishor Prasad, S. Ganesan, Prince Singh and Amit Kumar
475

In the present study, investigation on mechanical properties of effect of grading of aggregate, size of fly ash and polymer content on Polymer Concrete (PC) with fly ash as fillers was conducted. The polymer-based concretes were also exposed to elevated temperatures and tested to study the change in its mechanical behavior. The mechanical properties, i.e., compressive strength, split tensile strength, flexural strength, stress-strain behavior and modulus of elasticity of PCs and Ordinary Cement Concrete (OCC) were determined. The polymer and fly ash content were kept between 12.4%-13.2% and 7.6%-9.6%, respectively. The results obtained show that the PC possess significantly higher mechanical strength as compared to the respective OCC. Also, the polymer and fly ash content have to be controlled properly in order to achieve higher strength. The mechanical properties of PC depend on grading of aggregate and particle size of fly ash. The mechanical properties of PC exposed to elevated temperatures show satisfactory behavior up to 240°C, beyond which it decreases significantly.

47-37

Issue: February – March 2021, Vol. 47 No. 6

Optimization of copper slag for the production of green and sustainable concrete

E. Rahmathulla Noufal, A.K. Kasthurba and J. Sudhakumar
466
47-37

Issue: February – March 2021, Vol. 47 No. 6

Optimization of copper slag for the production of green and sustainable concrete

E. Rahmathulla Noufal, A.K. Kasthurba and J. Sudhakumar
466

There is a pressing need for an alternate solution for the natural fine aggregate in the construction industry since the availability of natural resources is decreasing tremendously due to urbanization and industrialization. On the other hand, increased waste generation enormously, the disposal of the industrial waste efficiently and economically is another big task. Therefore, utilization of industrial by-product in concrete is not only a method to dispose the industrial waste but also enhances the construction industry. In this paper, we discuss in detail the possibilities of utilizing copper slag, a by product obtained during the smelting and refining of copper as an alternative for manufactured sand as fine aggregate in reinforced cement concrete through systematic evaluation of physical, mechanical and chemical properties. Various mix designs of M25 and m30 are prepared and the fine aggregate is replaced with copper slag in different proportions and conducted the strength tests. Nondestructive tests, durability tests, and compositional analysis (SEM-EDAX). The results suggest that copper slag can indeed be used as a fine aggregate replacement for manufactured sand reinforced cement concrete, without compromising on the quality, thereby contributing to the direction of environment friendly building materials with economic benefits, which is the need of the hour.

47-36

Issue: February – March 2021 , Vol. 47 No. 6

Fragility curves for steel-concrete composite shear wall RCC infill moment resisting frame...

P.P. Phadnis, and V.V. Karjinni
453
47-36

Issue: February – March 2021 , Vol. 47 No. 6

Fragility curves for steel-concrete composite shear wall RCC infill moment resisting frame...

P.P. Phadnis, and V.V. Karjinni
453

This paper aims to illustrate the influence of Brick Masonry Infill (BMI) in reinforced concrete (RCC) building-composite shear walls dual system using the capacity spectrum method. The capacity spectrum method captures the unpredictability and ambiguity related to capacity spectrum properties, damage states, and characteristics of ground motion. Spectral displacement-based fragility curves and damage probability matrices subjected to different damage states are generated for the bare frame, frame with only BMI and frame-steel concrete composite shear walls (SCCMSWs) system with BMI. From the comparative study of the damage probability matrices, it is concluded that frames with BMI and SCCMSWs have shown better performance during the action of the lateral load.

47-T3

Issue: December 2020– January 2021, Vol. 47 No. 5

The weld coefficient - a new parameter accounting for shear resistance of welded wire...

D. Rama Seshu, Ch. Manjula, T.D.G. Rao and C.B.K. Rao
440
47-T3

Issue: December 2020– January 2021, Vol. 47 No. 5

The weld coefficient - a new parameter accounting for shear resistance of welded wire...

D. Rama Seshu, Ch. Manjula, T.D.G. Rao and C.B.K. Rao
440

47-35

Issue: December 2020– January 2021, Vol. 47 No. 5

Effect of metallic and non-metallic fibre percentages and aspect ratios on the mechanical...

S. Vijaya Kumar, B. Dean Kumar and B.L.P. Swami
430
47-35

Issue: December 2020– January 2021, Vol. 47 No. 5

Effect of metallic and non-metallic fibre percentages and aspect ratios on the mechanical...

S. Vijaya Kumar, B. Dean Kumar and B.L.P. Swami
430

In the present experimentation, Fibrous Self-Compacting Concrete (FSCC) using mixed fibers (steel and glass, steel, and polypropylene) have been studied for its mechanical properties. It is attempted to know the effect of fiber percentage as well as the aspect ratios of steel fibers in various combinations. The aspect ratios of steel fibers tried were 20,30 and 40. Total fiber percentages adopted were 0.2, 0.4,0.6 and 0.8. Glass and polypropylene fibers have constant aspect ratios. By this, the smooth, uninterrupted flow of fibrous Self-Compacting Concrete (SCC) was obtained. The extent to which these fibers improve the mechanical properties of SCC is studied. Mineral admixtures of flyash and Condensed Silica Fume (CSF) were employed at 20% and 10% respectively as replacement of Ordinary Portland Cement (OPC) for additional beneficial properties. This investigation brings out the influence of mixed fibers at different percentages with different aspect ratios of steel fiber on the structural properties of SCC. The admission of fiber at a certain percentage contributes towards more compressive strength. A combination of glass with steel fiber contributed better tensile strength and flexural strength compared to polypropylene with steel fibers.

47-34

Issue: December 2020– January 2021, Vol. 47 No. 5

Local buckling requirements of carbon cold-formed circular hollow steel sections of mild-...

M. Dundu
423
47-34

Issue: December 2020– January 2021, Vol. 47 No. 5

Local buckling requirements of carbon cold-formed circular hollow steel sections of mild-...

M. Dundu
423

This paper assesses the current local buckling requirements of carbon cold-formed steel hollow sections under axial compression, using data from literature. A total of 39 Circular Hollow Steel Sections (CHSS s) are analysed, and these include 19 columns of mild steel and 20 columns of high strength steel. Variables in the study includes the length, diameter, thickness and material properties. The outside diameter-to-thickness ratio (d/t) for CHSS s of mild steel ranged from 48.72 to 249.23, while the outside diameter-to-thickness ratio (d/t) for CHSS s of high strength steel ranged from 16.15 to 46.84. The corresponding yield stress for mild steel ranged from 203.80 MPa to 622.80 MPa, while that of high strength steel ranged from 1341.00 MPa to 1405.00 MPa. A comparison with CAN/CSA-S16-09 and EN 1993-1-1, shows the limits of both standards to be too conservative. New slenderness limits are proposed to improve the design of these sections.

47-33

Issue: December 2020– January 2021, Vol. 47 No. 5

Taguchi statistical optimization of operational parameters of turning operations for AISI...

S.D. Majumder
416
47-33

Issue: December 2020– January 2021, Vol. 47 No. 5

Taguchi statistical optimization of operational parameters of turning operations for AISI...

S.D. Majumder
416

This research entails the analysis of Taguchi optimization for AISI 1045 steel considering tool life and surface roughness as the noise factors. The research investigation has been used to optimize the cutting parameters such as depth of cut, cutting speed and feed rate affecting the performance characteristics of the cutting tool used for turning operation. The L9 orthogonal array, Signal to Noise (S/N) ratio and analysis of variance (ANOVA) were used during the optimization process of the turning operation using a tungsten-carbide cutting tool. Furthermore, a confirmation test has also been performed to estimate the improvement of the noise factors such as tool life had an increase by 190% and decrease of surface roughness by 40%.

47-32

Issue: December 2020– January 2021, Vol. 47 No. 5

Seismic fragility assessment of a pipe rack structure in a petrochemical complex by...

P. Jayarajan
408
47-32

Issue: December 2020– January 2021, Vol. 47 No. 5

Seismic fragility assessment of a pipe rack structure in a petrochemical complex by...

P. Jayarajan
408

A typical petrochemical complex consists of various components of different complexities such as structures of various proportions, critical piping, tanks and massive compressors. The consequences of a seismic event in a process plant is severe compared to conventional civil structures considering that damage to even a single component would result in release of toxic gases and lead to an interruption in the production causing economical losses and threat to society and environment. Pipe rack structures with the supported piping systems represents an important item in petrochemical complexes, refineries and LNG plants as they run in kilometres of length connecting various process units in the complex. The seismic hazard posed by such structures is evident in that they carry piping systems with hazardous fluids and support other critical equipments such as air coolers and exchangers. The paper presents the seismic fragility assessment for a typical steel pipe-rack structure adapted from a petrochemical complex built in a region of moderate seismicity. Pipe rack structure is first verified for its capacity as per the European codes. The Incremental Dynamic Analysis (IDA) is then performed to obtain an insight into the dynamic response of the structural system in both the transverse and longitudinal directions. The fragility curves developed for different performance levels based on the IDA data are used for the seismic assessment.

47-31

Issue: December 2020– January 2021, Vol. 47 No. 5

Influence of corrosion inhibiting admixtures on strength and durability parameters of...

V.L. Satish, V. Ravindra and Linga Anitha
400
47-31

Issue: December 2020– January 2021, Vol. 47 No. 5

Influence of corrosion inhibiting admixtures on strength and durability parameters of...

V.L. Satish, V. Ravindra and Linga Anitha
400

Even though there are extensive studies conducted on the mineral admixtures to control chloride permeability, the very few studies were conducted in India on the usage of corrosion inhibitors in concrete in order to delay the corrosion process. The results of the laboratory studies conducted using two commercially available corrosion inhibitors to determine the effectiveness and their influence on strength and durability parameters of Portland cement concrete are presented in this paper. This study examined the workability, compressive strength, split tensile strength, flexural strengthdevelopment in concretes mixed with anodic inhibitor (calcium nitrite based) and bipolar corrosion inhibitor (amino alcohol based). The durability tests such as the Rapid Chloride Permeability Test (RCPT) and Water Permeability Tests (WPT) are also conducted to determine the effectiveness of inhibitors.Test results showed that addition of calcium nitrite based inhibitor has resulted in marginal increase of compressive strength of concrete at 28 days, whereas, the addition of bipolar inhibitor has resulted in marginal decrease of compressive strength of concrete at 28 days. Addition of both the inhibitors has improved the split tensile strength but reduced the flexural strength. The resistance to the penetration of chloride ions of concrete is marginally improved by adding both the inhibitors. Water permeability resistance was improved by adding both the inhibitors at 5% dosage.

47-30

Issue: December 2020– January 2021, Vol. 47 No. 5

Damping characteristic identification and damage assessment of a three-storey aluminium...

T.S. Akhila and K.P. Saji
390
47-30

Issue: December 2020– January 2021, Vol. 47 No. 5

Damping characteristic identification and damage assessment of a three-storey aluminium...

T.S. Akhila and K.P. Saji
390

Monitoring of the large structural systems for purposes of assessing the potential degradation of structural properties by identifying the dynamic characteristics is needed for assuring the safety of the system. Measurements made at a single point in the structure can be used to detect, locate and quantify the damage. In this work, a method for determining the damping characteristics and identifying the presence, location and severity of structural damage by observing the potential degradation of modal characteristics is presented. This method uses the dynamic properties obtained from the vibration response of the structure both in damaged and undamaged conditions. A three-storied aluminium base frame and 8 damage induced frames were experimentally studied by horizontal shake table. The damage was induced in the base frame by reducing the cross-section of the column. The experimental observations in terms of frequency, displacement and acceleration were used to obtain the dynamic characteristics of the structure. By comparing both theoretical and experimental results of the storey level deflection, the damping ratio of the structure is identified. The identified damping ratio corresponding to each frame is used in the damage assessment algorithm. This algorithm gives reduced storey level stiffness of the structure. The characteristics of the damage in 8 damage induced frames are identified from the results. The method is verified by comparing obtained reduced stiffness with manually calculated stiffness value. The reduction in the stiffness of each storey reflects the location of the damaged column. The analytical results show that the presented method can lead to satisfactory results in most cases.

47-29

Issue: December 2020– January 2021, Vol. 47 No. 5

Boundary condition effects on postbuckling response of functionally graded hybrid...

Sudhir Vummadisetti and S.B. Singh
373
47-29

Issue: December 2020– January 2021, Vol. 47 No. 5

Boundary condition effects on postbuckling response of functionally graded hybrid...

Sudhir Vummadisetti and S.B. Singh
373

Boundary conditions are one of the key parameters that have a significant effect on postbuckling response. In the current paper, flexural and in-plane boundary conditions are considered to study their effects on buckling and postbuckling responses of functionally graded hybrid plate with and without cutouts subjected to positive and negative in-plane shear loads. The quasi-isotropic (±45/0/90)2s layup sequence is considered in the plate for the numerical investigation with various shaped cutouts. The flexural boundary conditions include all four edges simply supported, two edges simply supported, and two edges clamped, and all four edges clamped while the in-plane boundary conditions are simply supported on all edges with different in-plane boundary restraints. The analysis is based on finite element method-based software ABAQUS. Postbuckling strength is predicted by non-linear analysis static-riks method in which geometric imperfections are incorporated and the first failure is predicted by Tsai-Hill failure criterion. The effect of flexural and in-plane boundary conditions on postbuckling strength of composite plates is explained distinctly. Buckling and postbuckling strengths are observed to be higher in plates with all edges clamped while it is lower in case of plates with all edges simply supported in case of flexural boundary conditions. PBC1 in-plane boundary restraint is having high buckling and postbuckling strengths amidst all in-plane boundary conditions. Though plates without cutout have higher buckling capacity, it is worth noting that functionally graded hybrid composite plate with diamond shaped cutout can resist higher in-plane shear buckling load than other shaped cutouts for both flexural and in-plane boundary conditions.

47-T2

Issue: October – November 2020, Vol. 47 No. 4

A novel method of using prefabricated weld mesh as longitudinal core reinforcement for...

D. Rama Seshu, Ch. Manjula, T.D.G. Rao and C.B.K. Rao
362
47-T2

Issue: October – November 2020, Vol. 47 No. 4

A novel method of using prefabricated weld mesh as longitudinal core reinforcement for...

D. Rama Seshu, Ch. Manjula, T.D.G. Rao and C.B.K. Rao
362

47-28

Issue: October – November 2020, Vol. 47 No. 4

Seismic soil structure interaction response of elastic and inelastic moment resisting framed...

Vishwajit Anand and S.R. Satish Kumar
344
47-28

Issue: October – November 2020, Vol. 47 No. 4

Seismic soil structure interaction response of elastic and inelastic moment resisting framed...

Vishwajit Anand and S.R. Satish Kumar
344

A structure subjected to operational dynamic loads or moderate levels of ground shaking is expected to remain elastic. However under severe earthquakes, which are not very frequent, the same structure is designed to exhibit inelastic behaviour and sustain some damage so as to achieve an economical design. This dual strategy of seismic design makes understanding of elastic as well as inelastic behaviour of structures important. The present study devises an algorithm to assess effects of soil-structure interaction on elastic and inelastic seismic response of structures with kinematic hardening using the substructure approach. The critical step involved in this approach is the determination of dynamic impedance functions. The dynamic impedance functions have been obtained from literature. Wherever required, plots in Gazetas (1991) have been digitized to obtain polynomial expressions. The dynamic analyses on SDOF idealizations of structures have been performed in MATLAB using Newmark γ-β method. Effects of few engineering design parameters, which encompass material and geometrical properties of a soil-structure system, on the structural response of SSI systems have also been explored. The present study is restricted to moment resisting framed reinforced concrete buildings founded on embedded raft foundations.

47-27

Issue: October – November 2020, Vol. 47 No. 4

Prediction of shear strength of reinforced concrete squat shear walls-comparative studies

G. Appa Rao and V. Sivaguru
319
47-27

Issue: October – November 2020, Vol. 47 No. 4

Prediction of shear strength of reinforced concrete squat shear walls-comparative studies

G. Appa Rao and V. Sivaguru
319

The prediction of shear strength of RC walls by various empirical, semi-empirical and code equations is highly deviating. The accuracy of such predictions is a great concern for the designers. Such deviation in the prediction needs to be addressed. Several predicting equations proposed and reported prominently in various sources have been assessed through statistically based 333 selective experimental data points. The box and whisker plot has been developed for the scatter of the ratio of predicted-to-measured ultimate shear strength for all the predictive equations. The deviation of the predicted shear strength of RC walls as per the existing equations has been inferred. The prediction of the shear strength of RC shear wall by very few equations are in close proximity with the statistical experimental data. Though several factors influence the shear strength of RC walls, the role of vertical and horizontal reinforcement, axial load, and boundary elements is still debatable. The selective main factors influencing the shear strength of RC walls have been emphasised. The refined predictive model has been described from the assessment of the data in terms of influencing factors on the shear strength and behaviour of RC shear wall. The best predictions have been validated with the popularly accepted experimental results.

47-26

Issue: October – November 2020, Vol. 47 No. 4

Response control of shear building model for ground motions using tuned mass damper and track...

Ciby Jacob Cherian T.M. Madhavan Pillai and A.S. Sajith
308
47-26

Issue: October – November 2020, Vol. 47 No. 4

Response control of shear building model for ground motions using tuned mass damper and track...

Ciby Jacob Cherian T.M. Madhavan Pillai and A.S. Sajith
308

This paper presents the results of experimental studies conducted on a small-scale model of a shear building subjected to ground motions. Performance of a Tuned Mass Damper (TMD) as a linear Dynamic Vibration Absorber (DVA) and a track Nonlinear Energy Sink (NES) as a nonlinear DVA are compared considering their effectiveness when employed in this model. Experimentation is carried out in a uniaxial shake table for 32 different earthquake ground motion time histories. The results show that the track NEShas a versatile nature in response control and is inherently stable, whereas the TMD in the presented form lacks versatility and has stability issues. As far as the reverse flow of energy from the DVA to the primary structure is concerned, track NESshowed better performance. The study also reveals that TMDhas a high potential as a vibration control device to reduce the maximum response.

47-25

Issue: October – November 2020, Vol. 47 No. 4

Modelling of wall panels and vertical joints between them for pushover analysis of a precast...

Aparup Biswal, K.V. Snehalatha Reddy, Amlan Kumar Sengupta and A. Meher Prasad
295
47-25

Issue: October – November 2020, Vol. 47 No. 4

Modelling of wall panels and vertical joints between them for pushover analysis of a precast...

Aparup Biswal, K.V. Snehalatha Reddy, Amlan Kumar Sengupta and A. Meher Prasad
295

In a precast concrete wall type building, the joints between the precast wall panels are critical interfaces of force transfer. This paper investigates the influence of modelling the grouted vertical joints (considered to be emulative joints) between the wall panels on the behaviour of a building under lateral loads. To quantify the influence, three different types of models were investigated (i) monolithic model without considering the joints, (ii) walls with gaps for the joints and (iii) walls with shear link: elements for the joints. Next, two different modelling approaches were considered: (i) reference models using two-dimensional (2D) membrane elements and (ii) simplified models using one-dimensional (1D) equivalent column elements. Nonlinear static pushover analysis was carried out on standalone wall panel assemblages (with and without openings) and on a typical midrise building. To capture the material nonlinearity under increasing roof displacement (drift), multi-layered membrane elements and point plasticity in the column elements were used for the two types of models, respectively. From the observed results, it was found that a model with gaps for the joints gives an overestimation of drift and conservative estimation of lateral strength compared to the model with link elements. Also, it was observed that the behaviour of a wall panel assemblage modelled using column elements was comparable to that of a model using membrane elements till the peak strength, with acceptable variation in the post-peak behaviour. Hence, it can be inferred that a model using column elements for the panels and link elements for the joints as demonstrated in this paper, is suitable for the pushover analysis of large buildings made of precast wall panels.

47-24

Issue: October – November 2020, Vol. 47 No. 4

Influence of earth pressure coefficient, bedding stiffness and ground water level on shallow...

Madan Magdum and Bilavari Karkare
284
47-24

Issue: October – November 2020, Vol. 47 No. 4

Influence of earth pressure coefficient, bedding stiffness and ground water level on shallow...

Madan Magdum and Bilavari Karkare
284

Underground metro stations are susceptible to the significant external loads such as earth pressure, water pressure, bedding stiffness and backfill soil cover. The ground imposes formidable challenges in design due to geological complexities, ground water, induced stresses, geological formation history etc. At the initial phase of project, the design is carried based on the available limited geotechnical information. However, further analysed and modified based on the detailed investigation. Hence, it is important to study the influence of earth pressure coefficient at rest (ko), Ground Water Level (GWL) and bedding coefficient (ks) on the design of underground metro stations to establish graphical interaction. The paper presents a parametric soil structure investigation for shallow cut and cover underground metro station having soil cover of minimum 2m on roof. The wide range covers most of the geotechnical conditions across cities in India. 3D Finite element models are analysed considering variation in governing loads and design bending moments at about 20 key locations are presented graphically. The study includes wide range of 132 non-linear 3-D finite element structural models. The sensitivity analysis benefits for optimisation, reducing risk due to uncertainties and to develop the preliminary structural analysis with respect to lower bound and upper bound parameters.

47-23

Issue: October – November 2020, Vol. 47 No. 4

Comparative study on shear performance of blended pozzolonic RC beams with fly ash and...

Harikrishna Damera, N.R. Dakshina Murthy and N.V. Ramana Rao
273
47-23

Issue: October – November 2020, Vol. 47 No. 4

Comparative study on shear performance of blended pozzolonic RC beams with fly ash and...

Harikrishna Damera, N.R. Dakshina Murthy and N.V. Ramana Rao
273

Shear failure in a reinforced concrete beam is a sudden failure which is associated with crushing of concrete and is a brittle failure. A structural designer should be aware of various components of shear resisting mechanisms particularly the shear resistance of concrete. In this regard, an experimental investigation was carried out on forty simply supported reinforced concrete beams, to examine their shear performance of with and without shear reinforcement. This paper reports the results of a laboratory based experimental study aimed at studying shear performance of blended concrete beams with fly ash and recycled aggregates. Blended concrete beams of M35 and M45 grades were produced by partially replacing the cement by 25 percent fly ash and the Natural Coarse Aggregates (NCA) were replaced by Recycled Coarse Aggregates (RCA) in different fractions of 0,25,50,75 and 100 percentages. The experimental shear strength of blended concrete beams was then compared with predicted shear strength evaluated from various international codes and some existing empirical models in order to adjudicate the relevance of the experimental shear strength with the predicted shear strengths for beams without shear reinforcement.

47-22

Issue: Augest– September 2020, Vol. 47 No. 3

Synergistic effect of SBR latex and steel fibres on mechanical properties of high strength...

Praphulla K. Deshpande, Keshav K. Sangle and Yuwaraj M. Ghugal
259
47-22

Issue: Augest– September 2020, Vol. 47 No. 3

Synergistic effect of SBR latex and steel fibres on mechanical properties of high strength...

Praphulla K. Deshpande, Keshav K. Sangle and Yuwaraj M. Ghugal
259

This study presents the synergistic effects of polymer and steel fibres on high strength concrete. The various physical/mechanical properties considered in this study are workability, compressive strength, flexural strength, shear strength and toughness. The reference mix having strength of 50.96 MPa is used throughout the study. The dosages of SBR latex (polymer) are varied as 5%, 10% and 15% by weight of cement and steel fibre content varied from 1% to 10% by weight of cement at the interval of 1%. Two curing regimes were considered in this investigation. Standard cubes of size 150mm, prisms of size 150  150  700mm, push-off specimens of size 150  150  450mm for single shear were prepared. A comprehensive casting and testing program was carried out with 324 specimens for 28 days. The workability of fresh concrete is found to be increased with addition of polymer in fibre reinforced concrete. The significant improvement in various strengths and toughnesses is achieved compared to the reference concrete.

47-21

Issue: Augest– September 2020, Vol. 47 No. 3

Finite element analysis of skew box-girder bridges under IRC-A loading

Preeti Agarwal, Priyaranjan Pal and Pradeep Kumar Mehta
243
47-21

Issue: Augest– September 2020, Vol. 47 No. 3

Finite element analysis of skew box-girder bridges under IRC-A loading

Preeti Agarwal, Priyaranjan Pal and Pradeep Kumar Mehta
243

A study on simply supported single-cell skew reinforced concrete box-girder bridge is presented herein. The analysis is carried out using a finite element based software SAP 2000 v.14.0.0. An existing model is considered first to validate the present results with the reported one. A convergence study is then performed for the model, considered for investigation, to decide the mesh size for ensuring reliable results. Total 64 models, subjected to dead load and IRC class-A wheel load, are considered for investigation. An exhaustive parametric study is carried out in which the maximum bending moment, maximum shear force, maximum torsional moment, and reactions in girders are calculated. Further, stresses and vertical deflection of bridges are calculated. The results are presented in the form of force ratios between the skew bridge and the straight bridge. The skew angle effect, up to 30°, is almost negligible on forces and deflections, and thus such bridges can be analyzed as a straight one. The influence of other factors like span, span to depth ratio, and girder spacing are also considered for investigation. The results obtained in the syudy may be useful to the design of skew box-girder bridges.

47-20

Issue: Augest– September 2020, Vol. 47 No. 3

Non-linear analysis of slender straight and curved girders under normal and thermal loads

Vijeet Shivappa, and Pabitra Ranjan Maiti
233
47-20

Issue: Augest– September 2020, Vol. 47 No. 3

Non-linear analysis of slender straight and curved girders under normal and thermal loads

Vijeet Shivappa, and Pabitra Ranjan Maiti
233

This paper deals with nonlinear analysis of slender steel I-girders as well as horizontally curved slender steel I-girders under normal conditions and elevated temperature conditions. Under normal conditions, the effects of temperature on the analysis were neglected and under elevated temperature conditions, the temperature varies gradually from 0°C to 800°C. Three different girders, one straight and two curved girders, were modelled using the ABAQUS software. Effect of slenderness ratio and radius (for horizontally curved girders) were studied for 30m long slender I-girders as well as 30m long slender horizontally curved I-girders under normal conditions and elevated temperature conditions. It was found that slenderness ratio affects the axial force in the straight girders but does not have any significant influence on mid-span deflections at elevated temperature. For horizontally curved girder, the effect of angle subtended by the whole girder at the centre (radius of curvature) does not seem to have any significance for gradually elevated temperature. When temperature reduces from 800°C (i.e. cooling) to 0°C, a significant reduction in mid-span deflection was observed for straight girders but no significant reduction in mid-span deflection of curved girders was found. Finally, it can be concluded that horizontally curved girders are badly affected by elevated temperature compared to straight girders.

47-19

Issue: Augest– September 2020, Vol. 47 No. 3

Buckling analysis of space frames using experimental and numerical techniques

Narayan, Abhishek Sharma and Krishna Kant Pathak
227
47-19

Issue: Augest– September 2020, Vol. 47 No. 3

Buckling analysis of space frames using experimental and numerical techniques

Narayan, Abhishek Sharma and Krishna Kant Pathak
227

In this paper, the study of the buckling modes and the effective length of bars in steel welded space frames has been carried out experimentally and numerically using FEM based software. A 3D model of the under-slung bridge has been used for the experimental and numerical study. The bridge model has been designed in such a way that buckling takes place in the top chords. Effective length for each buckling bar is obtained by experimentation and comparison has been done with simulated results. For the calculation of effective length using simulated results, the distance between the points of contra-flexure has been used. This study provides an insight into the significant variations in the buckling behaviour of the frame members with the change in the buckling modes and with the change in the size of the members connected with the buckling member.

47-18

Issue: Augest– September 2020, Vol. 47 No. 3

Experimental behavior of rowlock walls retrofitted with different details under cyclic loading...

Xiao-Bing Li and Wei Li
220
47-18

Issue: Augest– September 2020, Vol. 47 No. 3

Experimental behavior of rowlock walls retrofitted with different details under cyclic loading...

Xiao-Bing Li and Wei Li
220

In the Yangtze Basin and southern China, there are a large number of rural buildings with rowlock wall. Because China is an earthquake-prone country, the application and strengthening of rowlock wall houses in earthquake region is a critical issue. However, strengthening of rowlock wall house is lack of a clear code or specification. This study presents the cyclic loading test of four rowlock walls with different strengthening details. The test results demonstrate the damaged rowlock walls can restore their original ultimate bearing capacity; it is also indicated that the use of cracking mending with steel mesh mortar covering repaired the walls improves the seismic behavior of the rowlock wall.

47-17

Issue: Augest– September 2020, Vol. 47 No. 3

A fuzzy model for optimum percentage of pond ash in concrete

K.M. Bagwan, S.S. Kulkarni, R.K. Lad and P.S. Dange
207
47-17

Issue: Augest– September 2020, Vol. 47 No. 3

A fuzzy model for optimum percentage of pond ash in concrete

K.M. Bagwan, S.S. Kulkarni, R.K. Lad and P.S. Dange
207

Pond ash is byproduct of thermal power station which is generated due to deposition of felled fly ash and bottom ash in large ponds. This paper discusses the development of Fuzzy Multiple Criteria Decision Making (FMCDM) model for estimation of Optimum Percentage of Pond Ash in Concrete (OPPAC). An every year huge amount of ash remains unutilized and dumped in ash ponds. Its leads to different types of pollutions like air pollution, water pollution and land pollution. One of the effective ways to utilize this waste is to replace cement partially with pond ash and to achieve sustainability in concrete construction. Here, a fuzzy model is developed to use appropriate percentage of pond ash in concrete. The fuzzy technique used in present study, estimates the optimum percentage of pond ash in concrete, taking into consideration the concrete performance parameters i.e. Workability, compressive strength, physical properties, chemical properties and setting time and not only compressive strength.

47-16

Issue: Augest– September 2020, Vol. 47 No. 3

Effect of binder content in alkali activated high performance concrete

Subhash C. Yaragal, B. Chethan Kumar, Anil Kulkarni, Akshay Kumar and Prashanth Kumar
195
47-16

Issue: Augest– September 2020, Vol. 47 No. 3

Effect of binder content in alkali activated high performance concrete

Subhash C. Yaragal, B. Chethan Kumar, Anil Kulkarni, Akshay Kumar and Prashanth Kumar
195

Alkali Activated High Performance Concrete (AHPC) is an innovative concrete that belongs to the spectrum of alkali activated materials. AHPC uses the concept of involving two different domain of concretes such as Alkali Activated Slag Concrete (AASC) and High Performance Concrete (HPC) in a right manner to obtain sustainable HPC. In the current study, Ground Granulated Blast furnace Slag (GGBS) is used as full replacement to Ordinary Portland Cement (OPC). GGBS is a byproduct obtained from iron-steel making industries. This binder contains silicates and aluminates, which acts as a precursor to AHPC. This study aims to optimize the different parameters like GGBS content (500, 550, and 600kg/m3), Silica Fume (SF) content (10, 15, and 20% of GGBS), and Quartz Powder (QP) content (10, 15, and 20% of GGBS) to obtain AHPC using Taguchi method of design of experiments. Further, to optimize different mixture proportion, Desirability Function Approach (DFA), Grey Relational Analysis (GRA), and Technique for an Order of Preference by Similarity to Ideal Solution (TOPSIS) were adopted. Results show that AHPC mixtures can produce 28 days compressive strength in the range of 91-107 MPa with flow value of around 150-170mm.

47-15

Issue: Augest– September 2020, Vol. 47 No. 3

Seismic acceleration amplification factor model for non-structural components in rc frame...

Ravinder Kumar Agrahari, K.K. Pathak Abhishek Sharma
181
47-15

Issue: Augest– September 2020, Vol. 47 No. 3

Seismic acceleration amplification factor model for non-structural components in rc frame...

Ravinder Kumar Agrahari, K.K. Pathak Abhishek Sharma
181

The Non-Structural Components (NSCs) of the structures require more awareness for seismic design so that it not only save the life but also minimise the economic loss. For the design of NSCs, the acceleration amplification factor is important, which is observed by inertia force exist in the building. Previous researchers worked in the field of amplification factor for higher hazard level and proposed that the amplification factor depends only on normalising height (ratio between height of the floor to total height of the building concerning base) and fundamental period of the structures for any peak ground motion, but it is found to be unsafe. However very few have paid attention to low to moderate hazard level. Even a low peak ground acceleration may amplify the strong acceleration significantly. In this paper, the peak horizontal floor acceleration of NSCs for low to moderate hazard level have been obtained. For this 2,4,6,8 and 10 stories moment-resisting RC frame models with low to moderate hazard level (0.01g-0.31g) have been considered. For the analysis 32 ground motion data in the range of 0.01g to 0.1g, 29 ground motion data in the range of 0.1g to 0.2g and 31 data in the range of 0.2g to 0.31g are considered using linear time history method. Based on analysis results, mathematical models are proposed to determine the absolute acceleration amplification factor. On comparison to other models it could be found that proposed mathematical models predict realistic values of acceleration for the safe design of NSCs.

47-T1

Issue: June – July 2020, Vol. 47 No. 2

Finite element analysis of hdpe utility poles reinforced with fiberglass rebars

Sriram Kalaga and Ramana Pidaparti
169
47-T1

Issue: June – July 2020, Vol. 47 No. 2

Finite element analysis of hdpe utility poles reinforced with fiberglass rebars

Sriram Kalaga and Ramana Pidaparti
169

47-14

Issue: June – July 2020, Vol. 47 No. 2

Programming for finite element analysis for transient elasto-plasticity in concrete using 3D brick...

A.S. Joshi and L.M. Gupta
152
47-14

Issue: June – July 2020, Vol. 47 No. 2

Programming for finite element analysis for transient elasto-plasticity in concrete using 3D brick...

A.S. Joshi and L.M. Gupta
152

Finite Element Method (FEM) of analysis is a very powerful computational tool. The objective of the paper is to summarize the theory and the associated programming algorithms developed for a 3 dimensional, 8 noded brick element employing isoparametric formulation. The dynamic elasto-plastic analysis is required for analysis of special problems in civil engineering like analyzing the effects of collision due to a vehicle or an errant ship on bridge structure, application of a moving force like wheels of a loaded truck moving on the deck. A set of connected subroutines were developed to investigate concrete bridge piers subjected to collision loads. The developed subroutines can also be employed to investigate the elasto-plasticity induced in concrete subjected to any dynamic load, with a few modifications as required by the user. The programs are validated using ANSYS software with acceptable difference in the results. An attempt is made to document a systematic algorithm of the programs developed to solve the problem of material non-linearity in concrete coupled with dynamic analysis using a three dimensional element.

47-13

Issue: June – July 2020, Vol. 47 No. 2

Experimental study of corrosion in steel fiber reinforced concrete incorporating alccofine using...

Saurav and Pratyush Malaviya
144
47-13

Issue: June – July 2020, Vol. 47 No. 2

Experimental study of corrosion in steel fiber reinforced concrete incorporating alccofine using...

Saurav and Pratyush Malaviya
144

This study focuses on the effect of corrosion in concrete due to change in parameters like w/c ratio, cover depth and reinforcement diameter. For this an experimental approach is carried out in laboratory where accelerated corrosion in the concrete was introduced by impressed current technique. In order to quantify the amount of corrosion occurred in concrete beams half cell potential method was used. Various results and patterns observed in this study is tabulated and thoroughly discussed in successive chapters. In order to find the change in mechanical strength in concrete due to corrosion flexural strength of beams were determined using center point loading method. Faraday’s law is used to find theoretical mass loss in reinforcement due to corrosion and results were compared with that obtained from experimental investigation. For the purpose of experimental investigation two different types of additives were added during casting of concrete. Firstly ultra fine slag Alccofine-1203 is used as partial replacement of cement. Addition of alccofine increases the packing density of concrete thus making concrete less permeable and due to which concrete becomes resistant to corrosion. Other additive used in this research work is crimped steel fibers 1% by weight of volume fraction of concrete as per previous literatures. Addition of steel fibers hinders the electrochemical process at reinforcement surface by reducing the availability of water and oxygen. Different sets of combinations of theses additives were used and tested in laboratory to observe their effect in hardened concrete to counter corrosion.

47-12

Issue: June – July 2020, Vol. 47 No. 2

Experimental study on partial replacement of fine aggregates using recycled plastic waste beads in...

M. Ashok, P. Jayabalan, J. Daniel Ronald Joseph and V. Saraswathy
132
47-12

Issue: June – July 2020, Vol. 47 No. 2

Experimental study on partial replacement of fine aggregates using recycled plastic waste beads in...

M. Ashok, P. Jayabalan, J. Daniel Ronald Joseph and V. Saraswathy
132

Recycling and reuse of waste products are required for achieving sustainable development in construction sector. In order to meet the growing demand for fine aggregates, numerous research studies have already been reported in literatures on the feasibility of using several industrial byproducts such as copper slag and waste foundry sand as partial replacement material for conventional fine aggregates, and promising results have been obtained. In this research, an attempt is made to use Recycled Plastic Wastes (RPW) obtained by recycling only plastic carry bag wastes as fine aggregates in cement concrete production. Different percentages of untreated and chemically treated RPW fine aggregates were used to replace conventional fine aggregates, and the properties of concrete such as compressive strength, flexural strength and splitting tensile strength were determined. Scanning Electron Microscopy (SEM) images were obtained from the tested samples of concrete. The quality of concrete with RPW fine aggregates was determined using Ultrasonic Pulse Velocity (UPV) method and compared with that of control concrete. The test results showed that concrete with treated RPW fine aggregates achieved higher strength than the concrete with untreated RPW fine aggregates. Concrete with strength up to 80% of control concrete could be achieved by using 10% of treated RPW fine aggregates for replacing conventional fine aggregates. The quality grading of concrete based on UPV tests was “excellent” or “good” for all levels of replacement considered in the present study. Equations based on regression analysis were proposed to predict the flexural and splitting tensile strength of concrete with untreated and treated RPW fine aggregates.

47-11

Issue: June – July 2020, Vol. 47 No. 2

Influence of support idealization on free vibration response of cooling tower shell

Sachin R. Kulkarni and Vinod Hosur
124
47-11

Issue: June – July 2020, Vol. 47 No. 2

Influence of support idealization on free vibration response of cooling tower shell

Sachin R. Kulkarni and Vinod Hosur
124

The idealization of support conditions for the hyperbolic cooling tower shell has significant influence on the free vibration response of the shell. Although considerable research is available in the literature regarding the behavior of the shell under different support conditions independently, the comparative study of different idealizations of support conditions on free vibration response of tower shell is the objective of the current study. Most of the researchers considered the pinned support or the fixed support for the shell and inferred that these idealizations adequately represent the free vibration response of the shell supported on columns. However, the current study indicates that the natural frequencies of the column supported shell is closer to the fixed/pinned idealization with the variation of 6-10% for the initial few modes only and vary to 40-50% in the higher modes.

47-10

Issue: June – July 2020, Vol. 47 No. 2

Seismic fragility analysis of pile supported wharf for some important port sites in Gujarat

Dhara Shah
111
47-10

Issue: June – July 2020, Vol. 47 No. 2

Seismic fragility analysis of pile supported wharf for some important port sites in Gujarat

Dhara Shah
111

In present study, seismic fragility curves are developed for a typical pile supported wharf, for some important port sites in Gujarat i.e. Mundra, Kandla, Navlakhi, Dahej and Hazira, thereby representing highest and moderate level of seismic zones of India (Zone V and III). Curves are developed for three levels of ground shaking i.e. Serviceability Earthquake (SE, 72 years return period), Design Based Earthquake (DBE, 475 years return period) and Maximum Considered Earthquake (MCE, 2475 years return period). The structural model of wharf is prepared in SAP 2000 using Winkler model to represent soil pile system. Pushover analysis is performed to obtain the capacity curve of wharf. Damage states - serviceable, repairable, near collapse and collapse; are established as per PIANC. Site specific spectra is constructed using geotechnical report of port sites with reference to ASCE7-05 and correspondingly 5 pairs of seismic events are selected, normalized and scaled to 0.1g, 0.2g,…1.0g to represent demand. Using Capacity Spectrum Method, maximum displacements at deck are obtained and response matrix is created. Based on the damage states and the response matrix, the fragility curves of the wharf are constructed. It is revealed that port sites Mundra, Kandla and Navlakhi are most susceptible to seismic risk, while Dahej and Hazira are comparatively at lower risk. Further, the specified spectra given in Indian standard underestimates the ground motions, particularly in zone V. Hence, site specific spectrum is essential for seismic design of port structures. At the same time a need is felt to strongly revise the Indian standard.

47-09

Issue: June – July 2020, Vol. 47 No. 2

A study on strain sensing and structural properties of RCC beam without stirrups using carbon fiber...

Arvind Kumar Cholkar and Manzoor Ahmad Tantray
100
47-09

Issue: June – July 2020, Vol. 47 No. 2

A study on strain sensing and structural properties of RCC beam without stirrups using carbon fiber...

Arvind Kumar Cholkar and Manzoor Ahmad Tantray
100

In present study, effect of micro carbon fibers on strain sensing property and structural behaviour of the reinforced concrete (RC) beams in absence of stirrups was experimentally investigated. A total of three RC beams of medium scale having dimensions of 125mm width, 350mm height and 1500 mm long were constructed without stirrups. All the three beams had different longitudinal reinforcement ratios (0.92%, 1.03% and 1.43%). All the beams had Carbon Fiber Based Concrete (CFBC) at top and bottom surface of the beam in mid span for a length of 350mm and depth of 78 mm. All the beams were tested to failure under four point bending test for evaluating strain sensing property and structural behaviour of Carbon fiber based concrete. Fractional Change in Resistance (FCR) was calculated for top and bottom surface of beam that had carbon fibers and co-relation between FCR of CFBC, concrete strain and strain in tensile reinforcement is plotted. It was observed that as load increases on the beam the FCR was increasing for bottom surface (tensile surface) and decreasing for top surface (compressive side). The trend of change in FCR for top and bottom surface is observed to be same as strain in tensile reinforcement and concrete changes respectively. It was also observed that this FCR can be used for strain and damage detection in beam as a NDT health monitoring approach. Further electrical properties and structural behaviour of all the beams is explained in detail.

47-08

Issue: June – July 2020, Vol. 47 No. 2

Wind-induced fatigue analysis of diagrid structural system for high rise steel buildings

Kartik Chaudhary, Sachin B. Kadam and Vijay N. Khose
93
47-08

Issue: June – July 2020, Vol. 47 No. 2

Wind-induced fatigue analysis of diagrid structural system for high rise steel buildings

Kartik Chaudhary, Sachin B. Kadam and Vijay N. Khose
93

Tall buildings are being constructed across the globe at an ever-increasing rate. The main reason for this is increasing population and paucity of land. Structural design of high-rise buildings is mainly governed by lateral loads due to wind or earthquake. Wind and earthquake loads are uncertain and random in nature. It is difficult to predict them correctly. Loadings on high-rise structures are different from low rise structures. Wind load is a major concern to high-rise structures, which not only causes vibration but may bring fatigue problems as well. To address this issue, in this paper an attempt is made to use, the equivalent structural stress method for the fatigue life assessment of a diagrid high-rise steel structure. Extended 3D Analysis of Building System (ETABS) 2017 software is used for modeling and analysis of structural system. By using the analysis results maximum stressed beam to column connection is identified. The finite element model of a welded beam to column joint is modeled and the corresponding loading is applied. ANSYS software is used for the finite element modeling and analysis. The results are presented and conclusions drawn show that the equivalent structural stress method is a mesh-insensitive method and it has the capability of unifying different stress-life curves (S-N curves) into a single master S-N curve.

47-07

Issue: April – May 2020, Vol. 47 No. 1

Free vibration of functionally graded carbon nanotube reinforced composite cylindrical shell panel...

A.K. Neelakantam and K.S. Sai Ram
80
47-07

Issue: April – May 2020, Vol. 47 No. 1

Free vibration of functionally graded carbon nanotube reinforced composite cylindrical shell panel...

A.K. Neelakantam and K.S. Sai Ram
80

In the present investigation, the linear free vibration of carbon nanotube (CNT) reinforced cylindrical shell panel with a cutout is studied using the finite element method based on a higher-order shear deformation theory. A higher-order theory is used to properly account for transverse shear deformation. An eight noded degenerated isoparametric shell element with nine degrees of freedom at each node is considered. Results are presented for the variation of the fundamental natural frequency of functionally graded CNT reinforced cylindrical shell panel with cutout size. A few typical mode shapes are also presented.

47-06

Issue: April – May 2020, Vol. 47 No. 1

Numerical simulation and parametric studies on the behaviour of concrete sandwiched double steel...

U. Mashudha Sulthana and S. Arul Jayachandran
65
47-06

Issue: April – May 2020, Vol. 47 No. 1

Numerical simulation and parametric studies on the behaviour of concrete sandwiched double steel...

U. Mashudha Sulthana and S. Arul Jayachandran
65

Concrete Filled Steel Tubular section (CFST) is found to possess high strength and stiffness properties and has been popularized in high-rise building projects. Nowadays, several alterations are made within this section to improve its structural performance at design as well as at the constructional level. Concrete Sandwiched Double Steel Tube (CSDST) is one such configuration that provides improved fire resistance, impact resistance and efficient connection detailing, in addition to high strength, stiffness and ductility properties. Since experimental investigations become very expensive to study the various parameters influencing their behavioural aspects, numerical techniques are adopted in recent studies. Even though numerical simulations bring ease in performing parametric studies, a well-established theoretical background is needed to correctly interpret its output data. In this study, a numerical model is developed for two types of sandwiched tubes, namely, circular inner and circular outer steel tubes (CSDST CC), and square inner and circular outer steel tubes (CSDST-CS), using ABAQUS software. Here, the concrete confinement equation proposed by the author for CSDST cross-section based on thick-walled cylinder theory is used for defining the concrete material model. The numerical model developed is validated with the experimental results available for CSDS T stub columns. Further, a parametric study is conducted to find the limitations on the proposed concrete confining stress. The proposed equation is found to be valid for a wide range of hollowness ratio of the cross-section with compact (class-1) outer steel tubes.

47-05

Issue: April – May 2020, Vol. 47 No. 1

Experimental investigation on the behavior of corroded chst columns retrofitted using afrp

S. Sivasankar and Nabajyoti Modak
55
47-05

Issue: April – May 2020, Vol. 47 No. 1

Experimental investigation on the behavior of corroded chst columns retrofitted using afrp

S. Sivasankar and Nabajyoti Modak
55

The paper presents an experimental investigation using Aramid Fibre Reinforced Polymer (AFRP ) composites on the retrofitting of corroded Circular Hollow Steel Tubular (CHST) column under axial compression. So far, the experimental investigation was limited to the use of FRP such as Glass Fibre Reinforced Polymer (GFRP) and Carbon Fibre Reinforced Polymer (CFRP) and also the way of application of FRP on the structure, i.e., the wrapping system. A study for the expediency of AFRP fabrics in the axial strengthening of CHST columns was done in this paper. The disadvantage of AFRP is the cost alone, so the full wrapping of the CHST sections with AFRP will be pricey. The assets of AFRP over steel structures are the low weight, ease in application and with a limited approach it can cover a maximum area. Total ten samples were tested including control and wrapped specimen in various techniques until the failure mode. The results obtained from different experiments were compared with the control sample and later the load-deflection and stress-strain properties were studied. The results from the experimental investigation admitted that, the external wrapping of AFRP fabric strips undoubtedly build up the load carrying amplitude of the CHST columns. The increase in the number of the layers of AFRP strips also effectively deferred the local buckling of the CHST columns by increasing the vertical displacement.

47-04

Issue: April – May 2020, Vol. 47 No. 1

Behaviour of steel special moment resisting frame buildings designed using current Indian code

Jones Joju and Rupen Goswami
36
47-04

Issue: April – May 2020, Vol. 47 No. 1

Behaviour of steel special moment resisting frame buildings designed using current Indian code

Jones Joju and Rupen Goswami
36

Seismic design codes recommend Force-Based Design method for design of Steel Special Moment Resisting Frame (SMRF) buildings. FBD relies on capacity design principles to contain inelastic action primarily in beams in SMRFs during strong earthquake shaking. Therefore, in line with the strength hierarchy required in capacity design, seismic design codes recommend guidelines/procedures for the design of capacity-protected components (such as connections, panel zones, and columns) in SMRFs. Although, the intent of the recommended procedures is same across various seismic design codes in this regard, few critical differences persist between the procedures outlined in Indian seismic design code and other seismic design codes (more specifically, the American and the European ones). The key differences are: (a) in recognising the expected increase in material yield stress from the minimum specified, or characteristic, yield strength of the material, (b) in estimating the demand on and the capacity of panel zones, and (c) in recommending a minimum column to beam strength ratio (CBSR ) for the design of columns in SMRFs. To assess the implication of the identified critical differences, two buildings, a 3-storey and a 9-storey with steel SMRFs, are designed compliant to the Indian code; then, the performance of the two buildings is evaluated using nonlinear static and dynamic analyses. The performance assessment of the designed buildings indicates undesirable behaviour wherein conventional expectation of resisting strong earthquake ground motion through ductile flexural plastic hinge formation at the beam ends is not realised. Finally, the two buildings are redesigned to account for the three issues mentioned above. The redesigned buildings are seen to demonstrate acceptable earthquake behaviour. Hence, a need is perceived to update the seismic design provisions of the current Indian code for steel SMRFs to ensure acceptable behaviour of such buildings during earthquake shaking.

47-03

Issue: April – May 2020, Vol. 47 No. 1

Performance of exterior RC beam-column joints using different concretes and reinforcement detailing...

G. Appa Rao and S. Kanaka Durga
24
47-03

Issue: April – May 2020, Vol. 47 No. 1

Performance of exterior RC beam-column joints using different concretes and reinforcement detailing...

G. Appa Rao and S. Kanaka Durga
24

Seismic activities demand special design and detailing of Reinforced Concrete (RC) structures, possessing adequate lateral strength, ductility and energy absorption capacity. The shear strength, ductility and energy absorption capacity need to be established for the type of concrete and detailing of lateral reinforcement for ensuring safety of RC joint region. In order to achieve adequate shear strength and ductility, beam-column joints in MRFs need to be designed with High Strength Concrete (HSC) and good reinforcement detailing. The premature joint failure can be prevented when HSC is used in the joint region and hence ensures sufficient load carrying capacity and energy dissipation. This study attempts to accomplish and investigate the performance of five geometrically identical exterior RC beam-column joints with different forms of detailing of reinforcement and also with steel fiber reinforced concrete in the joint region under reverse cyclic loading. The beam-column joints designed for gravity loads and routine live loads made up of low strength concrete are vulnerable to diagonal shear cracking under seismic loading. Adequate anchorage length of beam bars with closely spaced horizontal hoop reinforcement and use of fiber reinforced high strength concrete in the joint region plays predominant role in enhancing the shear strength and performance. Adequate anchorage length of beam bars and good detailing of reinforcement improve the joint shear strength and reduce the joint stiffness degradation. The joint shear strength, ductility, energy absorption and hysteresis pinching response have been improved under reversed cyclic loading with steel fiber reinforced HSC in the joint region. The deflection of beam and the corresponding load at the ultimate stage increase with good detailing in the joint region. The addition of small quantity of steel fibers in HSC could alter the failure of joint from brittle to ductile under reversed cyclic loads.

47-02

Issue: April – May 2020, Vol. 47 No. 1

Critical review of design of slab bridges as per IRC 112:2011

J. Chithra, Praveen Nagarajan, A.S. Sajith, and R.A. Roshan
13
47-02

Issue: April – May 2020, Vol. 47 No. 1

Critical review of design of slab bridges as per IRC 112:2011

J. Chithra, Praveen Nagarajan, A.S. Sajith, and R.A. Roshan
13

Earlier in India, for the design of concrete bridges, IRC 18 and 21 were used which are based on working stress method. Later the codes were combined to IRC 112-2011 which is based on ultimate limit state method. IRC 112-2011 provides a very interesting design method based on a three-layer sandwich model for the design of flexural members. This method is based on three dimensional linear elastic finite element analysis. The three-layer sandwich model got evolved from the Wood Armer method which was recommended in the earlier version of Eurocode; EN1992-1-1:2001. This paper intends to compare the area of reinforcement obtained from the two design methods with the popular effective width method provided in IRC 112-2011 which is an empirical method. Slab culverts with varying spans subjected to different loading conditions provided in IRC 6-2016 are compared for the parametric study.

47-01

Issue: April – May 2020, Vol. 47 No. 1

Strength and durability studies on concrete containing nano-fine cement

P. Venkatesan, R. Selvaraj and N. Palaniswamy
01
47-01

Issue: April – May 2020, Vol. 47 No. 1

Strength and durability studies on concrete containing nano-fine cement

P. Venkatesan, R. Selvaraj and N. Palaniswamy
01

The research paper presents the experimental results of mechanical strengths as well as the durability of nano-fine cement incorporated concrete. The present study is dealing with the pulverising the ordinary Portland cement to the nanofine scale (~250nm) using the high energy milling process, which is a top-down approach. The fine grind cement is explicated by particle size distribution analysis and by analytical techniques. Pulverising able to produce 50% of the cement particles < 250nm after 90 minutes milling. In the present research 0%, 10%, 20%, 30%, 40% and 50% of nanofine cement as partial replacement of cement in concrete mixture with 0.45 water-cement ratios was used. Mechanical strength properties of concrete have been investigated, and durability study includes corrosion resistance as well as resistance to chemical attack. Based on the experimental data, concluded that the 30% nanofine cement as a partial replacement, improves mechanical strengths and corrosion resistance of concrete.

46-SC

Issue: February – March 2020, Vol. 46 No. 6

Experimental investigation of cleat angle based exterior precast beam-column connections using...

Thulasirajan Krishnan and Revathi Purushothaman
485
46-SC

Issue: February – March 2020, Vol. 46 No. 6

Experimental investigation of cleat angle based exterior precast beam-column connections using...

Thulasirajan Krishnan and Revathi Purushothaman
485

46-T8

Issue: February – March 2020, Vol. 46 No. 6

State-of-the-art review on shrinkage behaviour of foamed concrete

Selija Khwairakpam, Indu Siva Ranjani Gandhi and Sritam Swapnadarshi Sahu
475
46-T8

Issue: February – March 2020, Vol. 46 No. 6

State-of-the-art review on shrinkage behaviour of foamed concrete

Selija Khwairakpam, Indu Siva Ranjani Gandhi and Sritam Swapnadarshi Sahu
475

46-39

Issue: February – March 2020, Vol. 46 No. 6

System reliability analysis of cold-formed steel lipped channel section panel

R.P. Rokade, K. Balaji Rao and B. Palani
457
46-39

Issue: February – March 2020, Vol. 46 No. 6

System reliability analysis of cold-formed steel lipped channel section panel

R.P. Rokade, K. Balaji Rao and B. Palani
457

Transmission Line (TL) systems and the TL tower as support structures are the vital infrastructure facilities. Conventionally these towers are fabricated using Hot Rolled Steel (HRS) angle sections. Nowadays, the use of Cold-Formed Steel (CFS) is gaining popularity in construction of general steel structures due to its cost effectiveness and numerous other advantages. An attempt has been made in this research work to carry out the experimental investigations on X-bracing panel replicating substructure of a TL tower made of CFS lipped channel sections. Prior studies by the authors on probabilistic analysis of capacity/resistance of CFS columns suggested the distribution of resistance, with modelling error as random variable seems to follow lognormal distribution irrespective of the design standards, and COV for simulated resistance with modelling error, as random variable is 0.3. The results of experimental investigations on CFS panel indicated that the individual member capacities calculated as per ASCE 10-15 (2015) standard are higher as compared to the member forces corresponding to panel failure load. Hence, it is proposed to carry out the system reliability analysis considering the possible uncertainty parameters. Present studies brought out the importance of consideration of the modelling error associated with the member strength estimation models given in design standards along with the variations present in material properties and loading. Further, estimations of component reliabilities for the panel members may not provide actual failure probability for the system and hence it is necessary to carry out system reliability analysis. While evaluating the safety margins for various failure modes, in order to determine the overall reliability of structural system, it is important to consider the correlations arising from the common sources of loading and common material properties. In this study failure probability has been estimated considering the series system for critical members contributing to overall failure of panel.

46-38

Issue: February – March 2020, Vol. 46 No. 6

Quality improvement of coconut shell aggregate in lightweight concrete

J. Jerlin Regin, P. Vincent, S. Carmel Jawahar and C. Ganapathy
449
46-38

Issue: February – March 2020, Vol. 46 No. 6

Quality improvement of coconut shell aggregate in lightweight concrete

J. Jerlin Regin, P. Vincent, S. Carmel Jawahar and C. Ganapathy
449

This study focused on the enhancement of quality of coconut shell aggregate using different pre-treatment methods and their effects in lightweight concrete. The degradability of coconut shell aggregate was tested by exposing the aggregate to severe alkaline, acidic and sulphate solutions. The quality of this aggregate was improved by providing pre-treatment with different chemicals. The properties such as water absorption, aggregate impact value and aggregate crushing value were tested. It was observed that coconut shell aggregate treated with 20% Poly Vinyl Alcohol (PVA) improved the performance of the aggregate. For instance, the water absorption of PVA treated aggregate was reduced to 42.27%when compared to that of non-treated aggregate. Furthermore, the aggregate treated with 20% PVA showed a marginal (only 5%) improvement in the strength of coconut shell aggregate concrete. Therefore, it may be concluded that coconut shell aggregate may not degrade when it is bound with concrete.

46-37

Issue: February – March 2020, Vol. 46 No. 6

Evaluation of long term compressive strength of concrete made with copper slag and...

C. Vijayaprabha
441
46-37

Issue: February – March 2020, Vol. 46 No. 6

Evaluation of long term compressive strength of concrete made with copper slag and...

C. Vijayaprabha
441

In this study the long term compressive strength was evaluated for the concrete made with polypropylene fiber and copper slag. This study aimed to investigate the mechanical property of concrete and to develop regression equations to predict the long term compressive strength of concrete. Copper slag was replaced with fine aggregate by 0.0% (control mix), 20%, 40%, 60%, 80% and 100%. Fibrillated polypropylene fiber of 0.2% to 0.8% volume fraction was added as an admixture. Compressive strength of concrete was estimated at various curing ages of 7, 28, 56, 90 and 180 days. Copper slag 40% and PPF 0.4% gives an optimum value of compressive strength at 28 days. Compressive strength was predicted at these ages using SPSS tool. Compressive strength predicted by 28 days curing period shows good correlation with the experimental values at 56, 90 and 180 days.

46-36

Issue: February – March 2020, Vol. 46 No. 6

Behaviour of ternary blend fibre reinforced geopolymer concrete under direct shear

Gopika Mohan, P.V. Indira and N. Ganesan
434
46-36

Issue: February – March 2020, Vol. 46 No. 6

Behaviour of ternary blend fibre reinforced geopolymer concrete under direct shear

Gopika Mohan, P.V. Indira and N. Ganesan
434

Direct shear strength have been studied on conventional concrete and ternary blend fibre reinforced geopolymer concrete. Earlier studies indicate that when fibres are added to concrete, it enhances direct shear strength and contribute to a reduction in spacing and width of cracks. Studies on direct shear strength of Ternary blend Geopolymer Concrete (TGPC) has not been investicated. Also, the effects on the addition of fibres on TGPC is not yet studied. The paper is intended to provide a basic understanding of the direct shear behaviour of TGPC reinforced with steel fibers. This paper presents the results of the use of Fly Ash (FA), Ground Granulated Blast Furnace Slag (GGBS) and Rice Husk Ash (RHA) as a ternary blend source material in Geopolymer Concrete (GPC). The study is limited to TGPC with 0.25%, 0.5%, 0.75% and 1% volume fraction of fibres. Push off specimen was used for studying the direct shear behaviour. It was found that fibre addition upto 1% delayed the crack propagation and showed better performance in the ultimate direct shear capacity and toughness than the conventional concrete specimens.

46-35

Issue: February – March 2020, Vol. 46 No. 6

An experimental investigation on shear strength of monolithic geopolymer concrete interface

B. Sumanth Kumar and D. Rama Seshu
426
46-35

Issue: February – March 2020, Vol. 46 No. 6

An experimental investigation on shear strength of monolithic geopolymer concrete interface

B. Sumanth Kumar and D. Rama Seshu
426

In recent times the Geopolymer Concrete (GPC) is gaining significance from the point of development of eco and environment friendly concrete using industrial by-products. The evaluation of mechanical characteristics of GPC paves the way for its structural use. In this paper the experimental study on shear strength of monolithic GPC interface is presented. This study includes different strength of GPC with and without reinforcement crossing the shear plane. The push off specimen prepared using GPC, were cast and tested. The results indicated that the shear strength of monolithic GPC interface has increased at higher rate up to GPC compression strength of 40 MPa. The presence of reinforcement across shear plane caused an increase of about 28% of the shear resistance against slip. The prediction equation proposed for the shear strength of GPC consists of contribution from friction, cohesion and dowel action of reinforcement at the interface. The push off test results was used to predict the coefficient of cohesion and coefficient of dowel action influencing the shear strength of GPC.

46-34

Issue: February – March 2020, Vol. 46 No. 6

Study on concrete-filled fluted steel tube columns

Elamathy and H. Jane Helena
419
46-34

Issue: February – March 2020, Vol. 46 No. 6

Study on concrete-filled fluted steel tube columns

Elamathy and H. Jane Helena
419

Concrete-Filled Steel Tube (CFST) columns combine the advantages of ductility, generally associated with steel structures, with the stiffness of a concrete structural system. Compared with the hollow steel tube columns, local buckling in the CFST columns is delayed due to the presence of concrete infill. Adding flutes to the columns can increase their moment of inertia and thus increasing the load resistance of the column. This paper presents the analytical and theoretical results of the study on behaviour of CFST columns with rectangular flutes. Normal grade concrete without reinforcement is used as in-fill. Number, position, and size of flutes are varied to understand the performance of flutes in structural strength enhancement of Concrete-Filled Rectangular Fluted Steel Tube Columns (CFRFST). Providing flutes is found to be beneficial and outward fluted columns are better than inward fluted columns. Four numbers of rectangular flutes provided outwardly of width D/3 and depth D/10 where D is the diameter of the CFRFST Column is found to be the most optimum cross-section of CFRFST columns considering the load carrying capacity and practical applications. Eurocode-4 is followed to generate non-dimensional P-M interaction curves for CFRFST columns with different steel contribution factors.

46-T7

Issue: December 2019 – January 2020, Vol. 46 No. 5

A state of art report on concrete and mortar containing farming waste

Mohankumar Namdeorao Bajad
406
46-T7

Issue: December 2019 – January 2020, Vol. 46 No. 5

A state of art report on concrete and mortar containing farming waste

Mohankumar Namdeorao Bajad
406

46-33

Issue: December 2019 – January 2020, Vol. 46 No. 5

A comprehensive test procedure for determination of shear strength parameters of brick...

S.R. Balasubramanian, K. Balaji Rao, A. Meher Prasad and R. Goswami
395
46-33

Issue: December 2019 – January 2020, Vol. 46 No. 5

A comprehensive test procedure for determination of shear strength parameters of brick...

S.R. Balasubramanian, K. Balaji Rao, A. Meher Prasad and R. Goswami
395

Shear strength is one of the important mechanical properties in the context of estimation of in-plane shear capacity of brick masonry piers or walls. This paper helps to identify the importance of standardization of test procedure and proposes a comprehensive test procedure for carrying out the shear strength test on brick masonry. Based on the identification that, dilatation is an important phenomenon in the shear strength test, a shear testing equipment that is capable for applying pre-compression using gravity is designed, fabricated and got employed in the experimental programme. The value of shear bond strength obtained from the test programme is quite comparable with the results available in the literature. However, for characterizing shear strength of brick masonry, results of the tests adopting a standardised procedure are required. It is also found that, in order to obtain COV of shear bond strength, it is important to carry out tests at more levels of pre-compression, not just three as is prescribed in many international standards.

46-32

Issue: December 2019 – January 2020, Vol. 46 No. 5

Shear resistance of steel fibre reinforced concrete beams

Shilpa Pal, Abhishek Kumar, Mohammed Arif and M. Shariq
384
46-32

Issue: December 2019 – January 2020, Vol. 46 No. 5

Shear resistance of steel fibre reinforced concrete beams

Shilpa Pal, Abhishek Kumar, Mohammed Arif and M. Shariq
384

The purpose of the present research is to investigate the shear behavior of fibre reinforced concrete beams under four point loading condition. Three types of fibres were examined: hooked-end steel fibre, crimped-steel fibre and continuous deformed-steel fibres. The experimental program consists of cubes to test the compressive strength of concrete, cylinders to test the tensile strength of concrete and beams to test the shear and flexure strength of concrete. Simply supported RC beams 150×150 mm cross section and 700 mm length were used in this study. The reinforcement was provided in three ways viz. conventional minimum steel reinforcement at top and bottom with stirrups in accordance with the provisions of IS 456, conventional minimum bottom steel reinforcement without stirrups incorporating crimped steel fibre in 03%, 0.4% and 0.5% dose and crimped steel fibre in 1.5% dose without top and bottom steel reinforcement and stirrups. The shear span to depth ratio was varied as 0.5, 1, 1.25 and 1.5. The experimental program consisted of twenty sets of beam specimens giving a total of forty beams in two replications each. The aim of this research is to investigate the effectiveness of fibres on the shear strength and ultimate load carrying capacities.

46-31

Issue: December 2019 – January 2020, Vol. 46 No. 5

Effects of variation of centres on the torsional analysis of asymmetrical buildings

Muhammed Masihuddin Siddiqui and N. Murali Krishna
375
46-31

Issue: December 2019 – January 2020, Vol. 46 No. 5

Effects of variation of centres on the torsional analysis of asymmetrical buildings

Muhammed Masihuddin Siddiqui and N. Murali Krishna
375

Presence of torsion makes the structural design of irregular buildings more complex and is prone to more severe damage. According to IS-1893:2016, a building is said to be torsionally irregular when the ratio of maximum horizontal displacement at any floor in the direction of lateral force to the minimum horizontal displacement at far end is more than 1.5. The torsional forces acting on a building are influenced by the relative location of the centre of mass, the centre of strength and the centre of stiffness. Therefore, these centres of significance shall be located aptly to minimise torsional effects on buildings to ensure efficient building structure. In this paper, the effects of strength eccentricity and stiffness eccentricity with respect to the centre of mass of the building are evaluated and non-linear dynamic analysis is carried-out to study the variation on torsional irregularity ratio and other torsional parameters. For the building structure, the structural configuration together with the sizes of structural elements are varied repeatedly to find-out the best locations of mass, stiffness and strength centres to minimize the torsional irregularity ratio. The study is found to be very productive as the torsional irregularity ratio gets reduced very significantly.

46-30

Issue: December 2019 – January 2020, Vol. 46 No. 5

Dynamic response analysis of a nose landing gear system of a propeller aircraft by...

K. Suresh, A.Vasanthanathan, P. Nagaraj and N. Selva Karthik
369
46-30

Issue: December 2019 – January 2020, Vol. 46 No. 5

Dynamic response analysis of a nose landing gear system of a propeller aircraft by...

K. Suresh, A.Vasanthanathan, P. Nagaraj and N. Selva Karthik
369

The main problem in the landing gear dynamics of the aircraft is either shimmy or brake induced vibration or ground induced longitudinal and lateral excitation due to runway unevenness. Neither of these vibrations is catastrophic, but still causes huge discomfort to pilots and passengers. Investigations on brake vibration were required, where a study of landing gear vibration due to brake chatter and squeal during taxi and landing was performed. It is essential to analyze vibration in aircraft due to the fact that while take-off and landing a very massive force acts on the landing gear, which tends to produce kinetic energy. Vibration would leads to the gradual deterioration of aircraft structure, which in turn affects both the passengers and crew. All vibrations have associated frequencies and magnitudes that should be identified. Basic dynamic theoretical studies of landing gear by modal and frequency response analysis using finite element method points out the design considerations required to reduce the level of vibration. An attempt has been made to reduce the vibration by providing stiffeners at the sensitive locations obtained using strain energy values and results were presented and compared for nose landing gear with and without stiffeners.

46-29

Issue: December 2019 – January 2020, Vol. 46 No. 5

Fly ash based geopolymer concrete with ferrochrome slag aggregates

P. Indu, S. Greeshma and P. Kiran Bedi
358
46-29

Issue: December 2019 – January 2020, Vol. 46 No. 5

Fly ash based geopolymer concrete with ferrochrome slag aggregates

P. Indu, S. Greeshma and P. Kiran Bedi
358

The technology of Geopolymer Concrete (GPC) is gaining importance in the present era because of the reduced carbon dioxide emission and low embodied energy, when compared with the conventional cement concrete. GPC is obtained by the activation of silica and alumina rich source materials in the presence of alkali activator. This paper evaluates the strength and durability characteristics of fly ash based GPC with ferrochrome slag aggregates. The fine and coarse aggregates in the GPC were replaced with ferrochrome slag in various proportions, and it was noted that the coarse aggregate replacement performed better than the replacement of fine aggregates. The optimum replacement percentage that gives the maximum strength in terms of coarse aggregate replacement was arrived at. The result concluded that the incorporation of ferrochrome slag as coarse aggregate at optimum level enhanced the strength characteristics in comparison with the conventional GPC with normal aggregates. The durability characteristics of the various replacement mix was carried out, and the results of the optimum replacement mix was compared with the conventional geopolymer mix. Apart from these, the feasibility of utilising ferrochrome slag as aggregates in concrete were also ascertained by leaching tests.

46-28

Issue: December 2019 – January 2020, Vol. 46 No. 5

Interaction diagrams for concrete shear wall reinforced with encased steel profiles

P.P. Phadnis and V.V. Karjinni
346
46-28

Issue: December 2019 – January 2020, Vol. 46 No. 5

Interaction diagrams for concrete shear wall reinforced with encased steel profiles

P.P. Phadnis and V.V. Karjinni
346

Axial force-moment interaction of Steel-Concrete Composite Shear Wall (SCCMSW ) under seismic loading is the focus of present study. Conventional Reinforced Concrete Shear Wall (RCSW ) is made composite by embedding vertical steel sections in the end zone. Current literature shows that, such composite sections are not addressed in developing countries codes. A new extended method to develop axial force-moment (P-M) interaction for SCCMSW , based on Eurocode 4 (2004) has been proposed and the results were compared with that obtained from SAP2000 v14 program for validation. Nonlinear static analysis has been performed to study damage pattern. It is concluded that the performance of frame with SCCMSW system is more efficient in terms of lateral stiffness and ductility than RCSW..

46-27

Issue: December 2019 – January 2020, Vol. 46 No. 5
Workability and compressive strength of self-compacting geopolymer concrete exposed to...

S. Jeeva Chithambaram, Sanjay Kumar and M.M. Prasad
337
46-27

Issue: December 2019 – January 2020, Vol. 46 No. 5
Workability and compressive strength of self-compacting geopolymer concrete exposed to...

S. Jeeva Chithambaram, Sanjay Kumar and M.M. Prasad
337

This paper reports the workability and compressive strength behaviour of geopolymer concrete using fly ash as the source material for the first part of the study. Also, partial replacement of fly ash by Ground Granulated Blast Furnace Slag (GGBFS) with 10%, 20%, 30% and 40% were investigated with varying NaOH concentrations of 8M, 10M, 12M and 14M. The workability of geopolymer concrete and its hardened properties were studied using different tests for flowability as per EFNARC specifications and Indian standard specifications, respectively. For the second part, the 28 days matured specimens were subjected to elevated temperatures from 200°C to 1000°C with an interval of every 200°C and their corresponding weight loss and deferred strength were studied. The test results indicated that the compressive strength of specimens under normal air curing increases with addition of GGBFS as partial replacement of fly ash up to 30% beyond which the strength decreases marginally. Also, the compressive strength values increase with increase in NaOH concentration up to 12M. Further, the increase in NaOH concentration to 14M shows a decrease in the compressive strength of Self-Compacting Geopolymer Concrete (SCGC) irrespective of the addition of GGBFS dosage. Tests on SCGC subjected to elevated temperatures showed that for all cases, the compressive strength value decreases gradually with an increase in temperature up to 400°C beyond which a steep decrease in compressive strength was found until 1000°C. The effect of elevated temperature on the compressive strength of SCGC had a direct relation with that of the weight loss with increase in temperature. The SCGC specimens prepared with 12M NaOH concentration and with 30% GGBFS as partial replacement of fly ash yielded the maximum strength with the different combinations experimented.

English