Numerical simulation and theoretical analysis research on flexural performance of hybrid beams composed of prefabricated UHPC permanent formwork and cast-in-situ concrete core reinforced by GFRP bars

• 1、School of Civil Engineering, Zhengzhou University, Zhengzhou 450001
• 2、School of Civil Engineering,Zhengzhou University,Zhengzhou 450001

Abstract：In this paper, from the perspective of improving the bending resistance of glass fiber reinforced polymer hybrid (GFRP) reinforced concrete beams, and put forward the prefabricated ultra high performance concrete (UHPC) permanent formwork-GFRP bars reinforced concrete hybrid beams and mixed reinforcement (GFRP bars, steel bars) concrete hybrid beams. It uses UHPC\'s excellent tensile and compressive resistance, good toughness and durability to improve the flexural stiffness, cracking load, ultimate load and durability of GFRP reinforced concrete beams and reduce crack width and deflection.In this paper, Based on the current FRP reinforced concrete specification and reinforced concrete specification and considering the tensile strength and compressive strength contribution value of UHPC, a new composite beam related theoretical calculation formula is proposed. It mainly includes the calculation method of the optimal thickness of the prefabricated UHPC permanent formwork under the condition of meeting the construction requirements; the calculation formula of the new type composite beam normal section flexural bearing capacity, the cracking load calculation formula, and the effective section inertia moment calculation formula. The MATLAB beam-splitting program was used to analyze the whole bending process of 13 beams, and the numerical simulation results were used to verify the calculation results.

Keywords： Structural engineering GFRP bars prefabricated UHPC permanent formwork new composite beam the theoretical analysis