| Rubber lightweight aggregate concrete is a kind of new concrete prepared by replacing rubber particles with lightweight aggregate.It has the characteristics of light weight,good ductility,good vibration resistance and heat preservation.Considering the many advantages of rubber lightweight aggregate concrete,rubber lightweight aggregate concrete and profiled steel plate were combined to form composite slabs with profiled steel sheet casted using rubber lightweight aggregate concrete in this paper.In order to systematically study the bearing capacity of rubber lightweight aggregate concrete slabs,the following research work are involved in this paper:1.Four profiled steel sheet casted using rubber lightweight aggregate concrete were designed,flexural bearing capacity test was carried out on the specimens.The effects of shear span and rubber lightweight aggregate concrete strength on the flexural capacity of specimens,strain on profiled steel sheets and concrete strain were studied.The results show that the flexural bearing capacity of rubber lightweight aggregate concrete composite slab increases with the reduction of shear span;rubber lightweight aggregate concrete composite slab has lower flexural bearing capacity than ordinary lightweight aggregate concrete slab,but the crack resistance is much better.2.Based on the experimental study,the ABAQUS finite element software was used to conduct the numerical simulation of profiled steel sheet casted using rubber lightweight aggregate concrete,the load-span deflection curve obtained by finite element simulation agrees well with the test curve.Then the influence of the thickness of the profiled steel plate,the thickness of the composite slab,the strength of the rubber lightweight aggregate concrete and shear span on the flexural bearing capacity of the composite slab were analyzed.The result shows that increasing the thickness of the profiled steel plate and the thickness of the combined slab can improve the flexural bearing capacity of the rubber lightweight aggregate composite slab.With the improvement of the strength of rubber lightweight aggregate concrete,the flexural bearing capacity of rubber lightweight aggregate concrete composite slabs is slightly improved,and the crack resistance is reduced.3.Based on the flexural bearing capacity test and finite element study,the spring2 element was used to simulate the slip between the profiled steel plate and the concrete based on push-out test results of YL76-688 profiled steel plate,and the finite element model was established to analyze longitudinal shear capacity of profiled steel sheet casted using rubber lightweight aggregate concrete.Based on the finite element model validated with the experimental results,the effects of end studs arrangement,stud diameter and shear span on the longitudinal shear capacity of rubber lightweight aggregate concrete slabs were analyzed.The results show that the arrangement of the end studs can effectively improve the longitudinal shear bond bearing capacity of rubber lightweight aggregate concrete composite slabs.Increasing the diameter of the end stud can improve the longitudinal shear bond bearing capacity of the rubber lightweight aggregate concrete composite slabs,but the degree of influence is small.With the increase of the thickness of the composite slabs,the longitudinal shear bond bearing capacity of the rubber lightweight aggregate concrete composite slabs increase.The longitudinal shear bond bearing capacity of the composite slabs decrease as the shear span increase.4.According to the experimental research and finite element calculation results,the flexural bearing capacity method of composite slabs with profiled steel sheet casted using rubber lightweight aggregate concrete were proposed.The longitudinal shear-bond capacity calculation formula of m-k method was obtained by the linear regression method.The longitudinal shear-bond capacity of rubber lightweight aggregate concrete composite slabs was calculated by PSC method,the advantages and disadvantages of m-k and PSC methods were analyzed.The finite element model was established and the calculation results of the oblique section shear capacity of the rubber light aggregate concrete composite slab were obtained.The finite element results were compared with the formula calculation results to verify the applicability of the oblique section shear capacity the calculation method of JGJ 138-2016.The stiffness of rubber lightweight aggregate concrete composite slabs was calculated by the converted section method and the reduced stiffness method considering slip.Comparing the calculation results with the results of the test and finite element analysis,Comparing the calculation results with the experimental and finite element results,the calculated results of the converted section method are unsafe after the crack of the combined slabs,the stiffness calculated results of the reduced stiffness method agree well with the experimental results. |
