i-manager's Journal on Structural Engineering (JSTE)


Volume 9 Issue 3 September - November 2020

Research Paper

Parametric Study on Performance of Box Girder with Variation of Cell and Configuration

Sandesh Dahal * , Satish Paudel**, Bikram Bhusal ***
* Chitwan Engineering Campus, Institute of Engineering, Tribhuvan University, Chitwan, Nepal.
** School of Civil Engineering and Technology, Sirindhorn International Institute of Technology, Thammasat University, Thailand.
*** National College of Engineering, Tribhuvan University, Lalitpur, Nepal.
Dahal, S., Paudel, S., and Bhusal, B. (2020). Parametric Study on Performance of Box Girder with Variation of Cell and Configuration. i-manager's Journal on Structural Engineering, 9(3), 1-7. https://doi.org/10.26634/jste.9.3.17301

Abstract

Box girder bridges are undoubtedly, one of the best options with a multitudinous number of advantages when compared to other options. The major objective of this research is to study the performance of the box girder section in determining the performance of the bridges with same widths and spans. For the purpose of this study, six box girder models (two cell and three cell girder) were analyzed for IRC Class 70R (wheeled loading) consisting of different cross-sectional properties. The performance in terms of vertical deflections and longitudinal bending stresses of these bridges with various cross-sections has been assessed. The influence of pre-stressing has also been studied and the results for one interior girder bridges were compared to those of two interior girder bridges for all different section types considered. After the numerical study of the box girder with variation of configuration (rectangular, trapezoidal and circular), the response in terms of displacement and longitudinal bending stresses of the rectangular bridge gave the minimum value when compared to trapezoidal and circular bridge in all the cases. Also, while comparing two cell and three cell box girder, the three cell girder bridges produce lesser deformations when compared to the two cell girder bridges which is due to an extra interior girder which improves the overall stiffness and structural integrity of the section.

Research Paper

Performance Prediction of Recycled Aggregate Concrete using ANN

B. Suguna Rao* , Srikanth. M. Naik **
*-** Department of Civil Engineering, M. S. Ramaiah Institute of Technology, Bangalore, Karnataka, India.
Rao, B. S., and Naik, S. M. (2020). Performance Prediction of Recycled Aggregate Concrete using ANN. i-manager's Journal on Structural Engineering, 9(3), 8-14. https://doi.org/10.26634/jste.9.3.16891

Abstract

Urbanization and industrialization has led to increased construction activities which is adversely affecting environment by increasing the quantum of waste being generated. India is generating about 48 million tonnes of solid waste out of which 25% of waste is developed from construction and demolition (C and D) waste. This increased quantum of waste needs to be handled to avoid impact on global warming. Huge demand of concrete as a material of construction increases the demand of natural aggregates to fulfill the needs of the construction activities. To overcome the huge demand of aggregates by effectively using natural aggregates along with C and D waste as recycled aggregates is one of the amicable solutions. Hence this work aims at preparing recycled aggregate concrete by partially replacing natural aggregates to provide a sustainable solution by utilizing recycled aggregates from C and D waste. The objective of this study is to prepare recycled aggregate concrete by partially replacing natural aggregates by recycled aggregates to achieve the strength required and predicting its performance using ANN for 28 days compressive strength by considering various input parameters that influences the strength of recycled aggregate concrete. Strength behavior of recycled aggregate concrete are predicted using ANN to understand its behavior for aggregates used from various sources. ANN helps in predicting the strength of recycled aggregate based on input parameters considered. Hence this study is carried out initially by preparing recycled aggregate concrete with various replacement ratios and validating using ANN. For validation of 28 day compressive strength, 148 data set is collected from the literatures and is used for testing and training ANN. ANN has the potential to validate for 28 day compressive strength.

Research Paper

Buckling Analysis of Modified Channel Sections under Axial Compression and Flexure

Sandesh Dahal * , Satish Paudel**
* Chitwan Engineering Campus, Institute of Engineering, Tribhuvan University, Chitwan, Nepal.
** School of Civil Engineering and Technology, Sirindhorn International Institute of Technology, Thammasat University, Thailand.
Dahal, S., and Paudel, S. (2020). Buckling Analysis of Modified Channel Sections Under Axial Compression and Flexure. i-manager's Journal on Structural Engineering, 9(3), 15-27. https://doi.org/10.26634/jste.9.3.17574

Abstract

Cold Formed Steel (CFS) sections although being light, thin, economic and efficient structural components are still vulnerable since buckling of such members is inevitable. The main objective of the research is to perform a numerical analysis for the evaluation of axial compression and flexural strength of the modified channel sections using direct strength method and CUFSM. Numerical study is performed by considering finite strip method in determining the stability of CFS sections. Then, using the results, a detailed finite element analysis is carried out through ABAQUS and domino effect are interpreted in terms of axial compression and flexural strength capacity. The comparison is performed by both CUFSM and ABAQUS for the same sections with varying width of flange as 110 mm and 125 mm and depth of web as 200 mm and 250 mm with thickness of 2 mm. Also, the boundary condition is varied as Simply supported and Fixed. Various sections are adopted so that comparison can be performed in terms of axial compression and flexural capacity. From the results as obtained for C1 and C2 sections by varying spans, support conditions and for two web depths and flanges, the axial and flexural capacities of sections obtained from ABAQUS are in good agreement with axial and flexural capacities obtained from CUFSM with the variation being 7.5%-12.5%. After performing the parametric study on various CFS sections it can be observed that as the number and web location of the CFS section is increased the governing buckling mode will be global. Being low weight and high tensile strength, the C1 type section can be used in bracing connection system.

Research Paper

Performance of High-Rise RC Building with Re-Entrant Corner in High Seismic Zone

Aruna Kote * , Sushma C. K.**
*-** Department of Civil Engineering, Dayananda Sagar College of Engineering, Bengaluru, Karnataka, India.
Kote, A., and Sushma, C. K. (2020). Performance of High-Rise RC Building with Re-Entrant Corner in High Seismic Zone. i-manager's Journal on Structural Engineering, 9(3), 28-36. https://doi.org/10.26634/jste.9.3.17565

Abstract

Irregular configuration and multi-storey buildings are becoming necessary to accomplish one of the basic requirements of growing population. Nevertheless, the irregular configuration of the buildings poses design challenges when subjected to earthquake. Study of former seismic actions has disclosed that plan irregular buildings exposes to critical damage due to immoderate torsion and stress accumulation. This paper presents a performance study on high-rise RC building with reentrant corner, which is a form of plan irregularity, in high seismic zone by varying the plan aspect ratio. Four buildings of Lshape, Plus-shape, I-shape and T-shape with 30 stories are analyzed by carrying out pushover analysis using ETABS17 software. Parameters such as ductility ratio, displacement, storey drift, base shear and stiffness are considered for the performance evaluation. In this paper a detailed study of the ductility ratio has been made and it can be concluded that the I-shape building is more ductile compared to all the other shape buildings.

Research Paper

Experimental Investigation on Flexural Members using Basalt Rebars and HYSD Bars as Concrete Reinforcement

P. Jagadeesan * , Peddireddy Shreeja Reddy **, Ragi Maniteja ***, Voruganti Sai Teja ****, Challa Datta Karthik*****
*_**** Department of Civil Engineering, Guru Nanak Institutions, Technical Campus (Autonomous), Hyderabad, Telangana, India.
***** Department of Civil Engineering, St. Martin's Engineering College, Hyderabad, Telangana, India.
Jagadeesan, P., Reddy, P. S., Maniteja, R., Teja, V. S., and Karthik, C. D. (2020). Experimental Investigation on Flexural Members using Basalt Rebars and HYSD Bars as Concrete Reinforcement. i-manager's Journal on Structural Engineering, 9(3), 37-60. https://doi.org/10.26634/jste.9.3.17680

Abstract

MEMBERS USING BASALT REBARS AND HYSD BARS AS CONCRETE REINFORCEMENT By ABSTRACT Basalt rocks are essentially an igneous class of naturally occurring mafic extrusive rock. When basalt rock is heated to a molten stage and formed into fibres, it is mixed with epoxy resins and moulded to form basalt rebars. Today, basalt rebars are a part of emerging technology, where their tensile strength is observed around 800-1350 MPa. This study primarily focuses on integrating these basalt rebars into the concrete as a reinforcing material in flexural members and analyzing their behavior in theoretical and functional study relative to conventional HYSD reinforcement. In this study, 2 sets of concrete beam specimens of M25 design mix concrete have been prepared each of size 700 x 150 x 150 mm. One set is made of HYSD reinforcement and the other with basalt rebars, and are subjected to flexure testing, after immersion curing process for 28 days. The various characteristics including maximum load carrying capacities, deflection, flexural strength and first crack point have been observed. Finally, the viability and adaptability for basalt as reinforcement is understood after the test results, in comparison with theoretical analysis.