Flexural behaviour of reinforced concrete beams with horizontal construction joints

Ali Al-Rifaie,Hisham Al-Hassani,Ali A Shubbar

doi:10.1088/1757-899x/1090/1/012003

Abstract

In the present research, ten simply supported reinforced concrete beams having a rectangular cross-section were cast and tested up to failure under the action of two-point loads. Eight of these beams were designed to contain horizontal construction joints (HCJs) of different number and location in the beam while the other two beams had no construction joint which were referred to as reference beams for the sake of comparison of results. All the tested beams had been designed to fail in flexure and had the same amount and type of longitudinal and transverse reinforcement as well as similar concrete properties. The results of this series of tests have indicated that the presence of HCJs in reinforced concrete beams leads to a decrease in its ultimate loads and increase in its ultimate deflection. The values of the recorded ultimate loads ranged between 83% to 98% times that of the reference beam while the ultimate deflection ranged between 102% to 133% times that of the reference beam.

Highlights

Construction joints can be defined as stopping places in the process of concrete casting
All the tested beams had been designed to fail in flexure and had the same amount and type of longitudinal and transverse reinforcement as well as similar concrete properties. The results of this series of tests have indicated that the presence of horizontal construction joints (HCJs) in reinforced concrete beams leads to a decrease in its ultimate loads and increase in its ultimate deflection
Flexural continuity can be achieved by ongoing the reinforcement through the joint, while the shear transfer is provided by shear friction between old and new concrete and/or dowel action in reinforcement through the joint [3,4,5,6] Different studies were conducted to investigate the response of structural members with construction joints to the quasi-static loading

Summary

Introduction

Construction joints can be defined as stopping places in the process of concrete casting. They are needed as it is difficult to place concrete in a continuous process for big structures. Flexural continuity can be achieved by ongoing the reinforcement through the joint, while the shear transfer is provided by shear friction between old and new concrete and/or dowel action in reinforcement through the joint [3,4,5,6] Different studies were conducted to investigate the response of structural members with construction joints to the quasi-static loading. Nagib et al [9] carried out an experimental study to investigate the flexural behaviour of single reinforced concrete beams having vertical construction joints. An experimental study was presented by Jang et al [10] to develop construction joints using ultra-high-performance

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Conclusion