Experimental Study on the Effect of Mixing Time on the Performance of High Strength Concrete

Abstract

To solve the problem of concrete quality caused by non-standard mixing time of high-strength concrete and improve the durability life of concrete structures, based on the working performance and mechanical properties of concrete, effect of mixing time on the workability and strength was studied. In this paper, for high-strength concrete with water-binder ratios of 0.31 and 0.38, the mixing time was 120 s, 160 s, 180 s and 240 s. The effects of different mixing times on the fluidity, cohesion and water retention of high-strength concrete and the compressive strength of 28 days were studied. The test results show that the appropriate mixing time benefits the working performance of concrete and the development of concrete strength. Based on the workability and mechanical properties of concrete, the mixing time of concrete with a water-binder ratio of 0.38 is 160 s, and the mixing time of concrete with a water-binder ratio of 0.31 is 180 s. To ensure the excellent uniformity, compactness, workability and mechanical properties of concrete, the mixing time should consider the slump and the water-binder ratio of concrete. For concrete with a water-binder ratio of 0.31 to 0.38, the mixing time can change from 180 to 160 s.