Study On The Influence Of The Bonding Degree Of The Overlapped Surface On The Bearing Performance Of The Concrete Laminated Plate

In recent years,all kinds of new prefabricated structures developed rapidly to adapt the national developing requirements on building industry.As the most important component of prefabricated concrete structure,the application and research of laminated plate have attracted extensive attention.According to the requirements of construction and structure,the composite component is poured a layer of concrete on the prefabricated component and then forming the two stress integral component.Therefore,it exists a joint surface between the new concrete layer and old,it means there is a "construction joint" at a certain level of a component.When the member is stressed,the "construction joint" has the possibility of disengaging.The bonding degree of superposed surface between the old and new concrete plays an important role to ensure the overall mechanical properties of composite members.This paper focus on the most representative laminated plates in laminated structures,study on the effect of bonding degree of composite surface on the bearing capacity of concrete composite slab.Through setting different number of anti-shear pin in laminated surface and form different bonding degrees,static loading test,theory and finite element analysis were used compared with the same size of cast in place slab,its bearing capacity(ultimate load,deflection,stress and strain)and cracks development were studied,the main content of the work and the conclusions are as follows:(1)consulting a large number of domestic and foreign literatures related to composite components,introducing their research status,and focusing on the study of the combination form of superposition surface(2)Three groups of 0,4 and 8 shear pins were designed and compared with the same size cast-in-place test,and the effect of different bonding degree on the load-bearing property of the plywood was studied.The experiment proved that weak laminated surface bonding degree of composite slab has a lower bearing capacity and a lager deflection than the Integral slab.It shows that the bonding degree of the composite surface has a great influence on the bearing capacity of the composite slab,with the number of shear pin implantation increased,the bonding degree grows better,the ultimate bearing capacity of composite slab gradually increase and approach to the integral slab,However,due to a certain bond and slip between pin and concrete,its deflection is greater than integral.(3)The theoretical analysis and research on the flexural capacity of ordinary concrete composite slab was carried out.The calculation model was established and the formula for calculating the bearing capacity of the composite slab was deduced.(4)a reinforced concrete composite slab model considering slip friction of.composite surface is established by ABAQUS,and the results are compared with those of composite slabs and slabs under different bonding degrees,The simulation results and experimental results fits well,it verify the reliability of the model.Based on that,the original parameters are used to simulate the change of the bearing capacity of the laminated plates of the span of 3M with the bonding degree of the composite surface changes,which also confirmed the preamble findings(5)From the experimental test and finite element simulation,it can be seen that the improvement of the bonding degree has a certain improvement on the bearing capacity of composite slab.Therefore,a variety of ways were suggested to increase the bonding degree of the joint surface in practical engineering,enhance the overall working performance of the post poured concrete and the floor.