Study On The Shear Performance Of ECC/RC Composite Beams

Concrete is a widely used and large amount of building materials in civil engineering construction.Since the advent of concrete,reducing its own weight,increasing its toughness has always been the focus of research,and the emergence of ECC materials has solved this problem.For this new type of material,scholars at home and abroad mainly focus on the study of material properties and bending members of beams,but there are few studies on shearing of ECC composite beams.Therefore,it is of great theoretical significance and application value to study the shear bearing capacity of ECC/RC composites without web reinforcement,to help engineers use materials more rationally,and to analyze and design concrete structures more scientifically.This paper as part of the National Natural Science Foundation of China's "Study on the Flexural Performance and Design Method of High-Strength Reinforced Concrete Functionally Graded Concrete Beams",designed and manufactured 38 ECC/RC composites without web reinforcement and 16 pure concrete contrast beams.Through static load tests,the effects of different shear span ratios,different interface treatments,different ECC layer thicknesses,and concrete strengths on the shear performance were studied,and based on the experimental results,the calculation formulas suitable for the shear bearing capacity were regressed with the data of this experiment to provide references for engineering applications.The main work of this paper is as follows:1.Perform compressive strength test on the concrete standard cubic test block that is manufactured and maintained in the same condition as the sample beam,and provide a basis for the static load test of the beam.2.Carry out static load test on the specimen beam,and observe the occurrence and development of bending cracks and shear cracks as well as the failure modes of the specimen beam.3.Analyze the results of the static load test,studied the influences of different shear span ratios,different interface treatments,different ECC layer thicknesses,and concrete strength on the oblique cracking load,crack development,deflection,and shear capacity of specimen beams,summarized the law of influence.4.Using the test data this time,select sum as the strength index,and return to the calculation formula suitable for the shear bearing capacity.The experimental results in this paper can provide references for the research and engineering application of ECC/RC composite beams without web ribs.