Research On Shear Behavior And Size Effect Of Steel Fiber High-strength Concrete Corbel Structure

Corbels are widely used in engineering structures such as power plants,industrial plants,roads and bridges,and are important load-bearing structures.Corbels support relatively large loads and have dynamic loads.Therefore,once the corbel is cracked or damaged,it may cause serious safety and quality accidents.With the actual needs of the project,the safety performance requirements of the corbel are becoming higher and higher.The corbel structure bears the action of bending moment and shear force.Due to the relatively small shear span,the corbel damage is mostly controlled by shear failure.At present,there are empirical formulas,strut-and-tie model,and shear friction theoretical models for calculating the shear capacity of the corbel.There are many coefficients in the formula and the scope of application needs to be further verified.The influence of the size effect on the shear performance of corbels is still unclear,and it is necessary to carry out experimental research to clarify.In this context,this article discusses the shear performance and size effect of highstrength concrete corbels through experimental research and finite element simulation analysis.And based on the experimental data and numerical simulation to compare and analyze the calculation models.The main work content is as follows:(1)This article systematically expounds the current research status of the shear performance of the corbel,leading to the insufficient research on the shear performance of the high-strength concrete corbel,and the necessity of studying the influence of the size effect on the shear performance.(2)The shear performance test of 27 corbel specimens was carried out to study the failure process and failure form of the corbel components.Through experiments,the effects of shear span ratio,longitudinally stressed steel reinforcement ratio,stirrup ratio,and steel fiber content on the mid-span deflection,concrete strain,and steel strain of the corbel specimens are analyzed.(3)Substitute the test data of 27 corbel specimens into the existing calculation formula for the shear capacity of the corbel.The applicability and accuracy of domestic and foreign normative formulas based on different theoretical calculation models and empirical formulas proposed by scholars from various countries are discussed.(4)Through the use of finite element software to simulate and analyze the 27 corbel specimens of the experimental design.By comparing the test results with the corresponding finite element results,it can be seen that the finite element simulation is more consistent with the actual test results.Using the existing data,we can further study the shear performance and size effect of the corbel.(5)Through the analysis of the characteristic load of the corbel specimen,in-depth study of the influence of the size effect on the shear performance of the high-strength concrete corbel.