Experimental study on flexural behavior of precast hybrid UHPC-NSC beams

Abstract

The main objective of this research was to evaluate the flexural behavior of precast hybrid Ultra-High Performance Concrete-Normal Strength Concrete beams. In this paper, a new precast hybrid Ultra-High Performance Concrete-Normal Strength Concrete beam was proposed, in which Ultra-High Performance Concrete was used in both the tension and compression zone of the cross section, while Normal Strength Concrete was adopted in the middle part, respectively. All six concrete beams were constructed and tested to study the flexural performance of precast hybrid Ultra-High Performance Concrete-Normal Strength Concrete beams. The results showed that (1) the proposed precast hybrid Ultra-High Performance Concrete-Normal Strength Concrete beams can still provide satisfactory bearing capacity, stiffness and ductility; (2) a larger crack width was observed in the precast hybrid Ultra-High Performance Concrete-Normal Strength Concrete beam when compared with Ultra-High Performance Concrete beams, which was mainly affected by the ratio of Normal Strength Concrete and Ultra-High Performance Concrete area and the reinforcement ratio; (3) the cost performance of precast hybrid Ultra-High Performance Concrete-Normal Strength Concrete beams can be improved by increasing the reinforcement ratio and the ratio of Normal Strength Concrete and Ultra-High Performance Concrete area; (4) the proposed model can accurately predict the moment capacity and deflection of the precast hybrid Ultra-High Performance Concrete-Normal Strength Concrete beam based on the experimental results. It is a new attempt to make reasonable use of such superior characteristics of Ultra-High Performance Concrete.