Experimental Study On Shearing Capacity Of Lightweight Aggregate Concrete PBL Connector

With the development of research on lightweight aggregate concrete,lightweight aggregate concrete has been applied to composite structures.At present,there are few researches on PBL shear connectors of lightweight aggregate concrete.In this paper,in order to explore the bearing capacity and influencing factors of PBL shear connectors of lightweight aggregate concrete,experimental re.search and finite element simulation were carried out.The main work is as follows:(1)This paper discussed the basic theory of PBL shear connector,summarized the calculation formula of bearing capacity in various scholars and relevant codes,analyzed the influence of various parameters on bearing capacity,and preliminarily determined the main influencing factors,providing a theoretical basis for the design of the test scheme.(2)Six groups of twelve PBL shear connectors were designed and tested.Among them,one group of ordinary concrete specimens and five groups of lightweight aggregate concrete specimens are set.The bearing capacity of PBL shear connectors of lightweight aggregate concrete was studied by changing the factors of the hole size of steel plate,concrete strength and diameter of the steel bar.(3)The test results show that:in the failure process,compared with ordinary concrete,the cracks of PBL shear connectors of lightweight aggregate concrete appear earlier and develop more slowly in a certain period of time.The specimen has a long crack working stage,but the crack of ordinary concrete appears late,and the crack development is obvious.Under the same parameters,the ultimate load of PBL shear connectors of lightweight aggregate concrete is less than that of ordinary concrete shear connectors,which is about 10%lower.(4)The analysis of test data shows that the main factors affecting the bearing capacity of PBL shear connectors of lightweight aggregate concrete are:concrete strength,the hole size of steel plate and diameter of the steel bar.Compared with ordinary concrete connector,the effect of steel bar diameter is slightly significant.(5)The finite element software ABAQUS was used to analyze the bearing capacity of PBL shear connectors of lightweight aggregate concrete.Several models were established,and the final calculation results showed that the bearing capacity of PBL shear connectors of lightweight aggregate concrete was 12%lower than that of PBL shear connectors of ordinary concrete,which was consistent with the test data.On the basis of the specimen,the main factors affecting the ultimate bearing capacity of PBL shear connectors are fully analyzed.At the same time,combined with the test data,the formula of bearing capacity is fitted,and the formula of ultimate bearing capacity for PBL shear connectors of lightweight aggregate concrete is put forward.