Shear behaviour of prestressed beams with high-workability concrete

Abstract

The purpose of this study is to investigate the shear behaviour of prestressed beams made with high-workability concrete and normal concrete under static load. A total of 18 prestressed beam specimens were made in this study; nine were prestressed high-workability concrete beams, and the rest were normal concrete beams. The specimens were all 400 mm deep T-sections, tested with two concentrated loads. The test parameters included concrete strength, amount of prestress, shear span-to-depth ratio and spacing of transverse reinforcement. The results show that prestressed high-workability concrete beams have better structural behaviour than prestressed normal concrete beams. The diagonal cracking strengths and ultimate strengths of high-workability concrete beams were 1·20 and 1·17 times those of normal concrete beams respectively. Prestressed high-workability concrete beams have better crack control ability than prestressed normal concrete beams. With the same crack width, high-workability concrete beams can reach greater loads which are approximately 1·21 times those of normal concrete beams. In addition, prestressed high-workability concrete beams have greater stiffness than prestressed normal concrete beams.