Nonlinear Analysis of Flexural Capacity of C-UHPC-Brick Masonry Composite Beams

This paper proposes a novel C-shaped UHPC-brick masonry composite underpinning beam section form. and its underpinning transformation method. The flexural performance of seven UHPC-masonry composite beams and three normal concrete-masonry composite beams were systematically studied by finite element simulation, with a focus on the effects of parameters such as reinforcement ratio, UHPC layer thickness and UHPC strength. The results showed that increasing the longitudinal reinforcement ratio and the thickness of UHPC layer can improve the yield load and peak load of the beam. When the reinforcement ratio increased from 1. 16 % to 1. 81 % and 2. 28 %, the yield load increased by 15. 9 % and 82. 53 %, respectively, and the peak load increased by 49. 3 % and 86. 6 %. When the thickness of UHPC layer was increased from 30mm to 90mm, the cracking load increased by 29 %. Compared with ordinary concrete composite beams, UHPC composite beams have a significant advantage in bearing capacity. Based on the assumption of plane section, the calculation formula of flexural capacity of this kind of composite beam was established. The calculation results were in good agreement with the finite eleme