The effect of construction joints on the bending capacity of singly reinforced beams with different reinforcing ratios

Abstract

The main reason behind conducting this study is to determine the effect the construction joint has on the flexural bending capacity of reinforced concrete beams. Several delays and problems occur during construction which lead to the stopping of concrete pouring. In order to solve this conflict a construction joint must be provided. In our experiment four different mix designs were utilized. Six variant steel ratios were used for each mix. For every mix design 36 beams were poured, half of which were monolithic and the other half had a construction joint on the beams center. In addition, 36 test cylinders were casted for each mix design. In total we tested 144 beams and 144 cylinders. Testing was conducted according to applicable ASTM standards. For each concrete compressive strength we calculated the ratio of moment construction joint over the moment monolithic. The final result showed that the ratio is very close to one which means that the moments are almost constant. This indicates that the presence of a construction joint has no significant impact on the flexural bending capacity.