Study On Local Compression Behavior Of HRB500 Reinforced Lightweight Aggregate Concrete Members

"Lightweight,high strength and good deformability" is one of the development directions of Engineering structures.In spite of light quality,lightweight aggregate concrete also has good strength and deformation performance,as well as good insulation,heat preservation and fire resistance performance.HRB500 reinforcement with high strength and good deformability,has been promoted as the leading reinforcement in the current national standard "Cord for design of concrete structure"(GB 50010-2010)Local compression is one of the basic mechanical properties of the structure,but by searching,it is found that the study on the local compression of lightweight aggregate concrete has been limited to the objects equipped with the indirect reinforcement,while those with both indirect reinforcement and HRB500 reinforcement has not been reported.This issue is urgently needed to be addressed in view of the practical demand and the revision of "Technical specification for lightweight aggregate concrete structures"(JGJ 12-2006).Therefore,the local compressive behavior of HRB500 reinforced lightweight aggregate concrete is systematically studied in this paper.The local compression performance test of 25 specimens which simulate the prestressed lightweight aggregate concrete beams with end anchorage(it is called the specimen Ⅰ in this paper)were finished,and the specimen failure patterns,features of the wedges and the load displacement curves was achieved.Based on the analysis of the test results,the influence of the parameters such as reinforcement,Ab/Al,Acor/Al and lightweight aggregate concrete strength on the local compression performance is obtained.Based on the fitting and analysis of the test data by two methods,considering the influence of HRB500 steel skeleton and the indirect reinforcement,estblished the formula of calculating the local compressive bearing capacity of the prestressed lightweight aggregate concrete beam with end anchorage.The local compression performance test of 25 specimens which simulate the lightweight aggregate concrete bent cap under the viaduct(it is called the specimen Ⅱ in this paper)were finished,and the test result was similar with specimen Ⅰ.By analyzing the test data,the influence of the parameters such as reinforcement,Ab/Al,Acor/Al and lightweight aggregate concrete strength on the local compression performance is obtained.Through fitting and analyzing the experimental data by two methods,the calculate formula for the local compression capacity of lightweight aggregate concrete bent cap which considering the HRB500 reinforcement skeleton and indirect reinforcement under the viaduct is proposed.By using two different analysis methods,the test data of all 50 specimens are fitted and analyzed,the formula of the local compression capacity of HRB500 reinforced lightweight aggregate concrete members is received.Further,using ABAQUS for modeling analysis,the load displacement curve,failure shape and characteristics as well as the influence of the parameters such as reinforcement,Ab/Al,Acor/Al and lightweight aggregate concrete strength on the local compression performance is revealed The comparison between the results of test and the numerical simulation shows that the numerical simulation analysis method of the local compression performance is feasible.The major research results of this paper provide the technical support for the revision of the national construction industry standards "Technical specification for lightweight aggregate concrete structures"(JGJ 12-2006).At the same time,the suggested formula of local compression bearing capacity is adopted by this procedure.