Experimental Study On Bending Performance Of High-strength Stainless Steel Reinforced Concrete Beams

Reinforced concrete structures are widely used in civil structures,but structural failure caused by corrosion is common.The application of high strength stainless steel reinforcement in reinforced concrete structure can effectively improve this problem,so it is very meaningful to carry out research on high strength stainless steel reinforcement concrete structure.The bending behavior of high strength stainless steel reinforced concrete beams is studied experimentally.The main contents are as follows:Through the three-point loading method,the beam is loaded,and the data of load,crack width and strain are obtained.The applicability of the crack width calculation formula and the bearing capacity calculation formula given in Code for Design of Concrete Structures(GB50010-2010)to the high-strength stainless steel reinforced concrete beams is studied.The results show that the bearing capacity of high-strength stainless steel reinforced concrete beams increases with the increase of section size,reinforcement diameter,reinforcement ratio and other parameters.The crack width calculation formula and bearing capacity calculation formula given in the code are still applicable to high-strength stainless steel reinforced concrete beams.The second test used UHPC instead of ordinary concrete.Since the tensile strength of concrete is not considered in the calculation of ordinary reinforced concrete beam,and the compressive strength and tensile strength of UHPC are much higher than ordinary concrete,the calculation formula of flexural capacity of ordinary reinforced concrete beam is not suitable for UHPC beam with high strength stainless steel reinforcement.Based on the test results,a formula for calculating the flexural capacity of UHPC beams with high strength stainless steel bars is proposed.Considering the existence and randomness of steel fiber distribution,as well as the improvement of mechanical properties of UHPC and high-strength stainless steel,the crack width calculation formula was modified by combining with the test data.The finite element simulation of the test beam was carried out by ABAQUS software,and the test results agree well with the simulation results.The parametric analysis of concrete strength,section area,reinforcement ratio and other parameters is carried out.The parametric analysis results show that the bearing capacity of highstrength stainless steel reinforced concrete beam increases with the increase of the above parameters.The simulated values are in good agreement with those obtained from the formula for calculating the bending capacity of UHPC beams with high strength stainless steel reinforcement.The bending performance of UHPC beam with high strength stainless steel reinforcement is compared with that of concrete beam with high strength stainless steel reinforcement.The results show that UHPC beam with high strength stainless steel reinforcement bears more load than concrete beam with high strength stainless steel reinforcement under the same section size,reinforcement ratio and reinforcement type.In the tensile area after cracking,UHPC can continue to bear the stress,assist the work of the steel bar in the cracked area,and reduce the crack width.