Experimental study of continuous T-beams with negative bending moment using UHPC instead of prestressed tendons under flexure

Abstract

In order to explore the flexural performance of the two-span simply supported to continuous T-beam using UHPC material instead of prestressed tendons in the negative bending moment zone and the effect of the UHPC material connection length on the bearing capacity of the test beam, the flexural tests of three beams with different UHPC connection lengths were carried out. The results show that by using UHPC material instead of prestressed tendons to make continuous beams in the negative bending moment region, the tensile properties and high elastic modulus characteristics of UHPC material can be better exerted. The three test beams were all resistant to bending failure, and the cracks were distributed in the two positive and negative bending moment sections. Increasing the connection length of the UHPC material will increase the distribution range of cracks and the number of cracks in the positive moment section and the cracking load in the negative moment section. The ductility was reduced. When the connection length was increased from 300 mm to 2200 mm and 2300 mm, respectively, the bearing capacity of the test beam was increased by 4% and 6%, respectively, and the mid-span ultimate displacement was reduced by 7% and 12%, respectively. The flexural performance of the test beam was improved.