The development and performance evaluation of diagonal tension cracks control devices

Abstract

ABSTRACT The cause of diagonal tension cracks is the drying shrinkage of the initial concrete, which causes them to appear at the corners of square openings, which are the most vulnerable areas to stress. Looking specifically at the cause from a structural aspect, the concentrated stress exceeds the tensile strength of the concrete, causing cracks to occur at the corners. Typically, diagonal tension reinforcement bars are arranged to prevent diagonal tension cracks, however, they have often failed to be practical solutions because they do not entirely prevent the continued occurrence of cracks. Consequently, the present study developed diagonal tension cracks control devices that are capable of preventing diagonal tension cracks. Next, comparative experiments on existing diagonal tension reinforcement bars with respect to drying shrinkage were conducted to verify the utility of the diagonal tension crack reinforcement materials through performance evaluation. According to the results, the maximum elastic strain at the top and bottom opening edges was 29.2% and 35.8%, respectively, which was a large reduction compared to the 6.7% and 4.9% of the existing diagonal tension reinforcement. Considering the above points, it is expected that the developed control device will be very practical in terms of industry.