Effect of construction joints on the splitting tensile strenght of concrete

Abstract

The purpose of this study is to associate the compressive strength of concrete (fc) with the splitting tensile strength of concrete (t) where a construction joint exists, and come up with an equation relating t to fc. The American Society for Testing and Materials (ASTM) and the American Concrete Institute code (ACI 318-08) provides us with the testing methods and standards, as well as theoretical and experimental formulas for our use. The formulas provided to us are for the correlation of t to fc. Never the less they are suggested for concrete specimens, who are monolithic, meaning that the specimens do not contain joints. This equation would prove useful for knowing the reduction in the splitting tensile strength of concrete with the existence of a construction joint. It is well known that construction joints are used in every concrete structure, which tells us that engineers would definitely benefit from an equation that could relate the splitting tensile strength of concrete in function of its compressive strength. The results suggest that the reduction in the splitting tensile strength in the presence of a construction joint is not as much as most engineers tend to believe. Due to that belief, most engineers tend to overdesign for steel reinforcement at those joints to compensate for this reduction. Our aim is to better the understanding of the effects of a construction joint on the splitting tensile strength. And hopefully this will help engineers in their design calculations, therefore reducing the amount of steel reinforcement at the joints. Thus also leading to cost saving on projects.