| The lightweight aggregate concrete composite slabs with profiled steel sheet,as a new type of floor system,do not only have characteristics of ordinary aggregate concrete composite slabs,but also have advantages of light deadweight,insulation,being environmentally friendly,which make significant economic and social benefits.Recently,researches on ordinary aggregate concrete composite slabs have been carried out extensively and deeply.However,it is relatively poor for researches on lightweight aggregate concrete composite slabs.Besides,longitudinal shear-bond property has a direct influence on deflection,slip and bearing capacity.As a result,it is especially important to study longitudinal shear-bond property.In this paper,7 full-scale test pieces of lightweight aggregate concrete composite slabs with common YX76-344-688 profiled steel sheet were made and longitudinal shear-bond property of which was studied.The specific research contents and conclusions are as follows:(1)The change rules about strain,slip and deflection during longitudinal shear-bond failure were fully analyzed and some factors that affect the bearing capacity when longitudinal shear-bond failure were investigated.The results show that the shear-span,the thickness of composite slabs and shear reinforcement have different effects on the bearing capacity of composite slabs.(2)The important parameters for predicting the longitudinal shear capacity were obtained by m-k method and PSC method.Compared with other documents,the coefficients m and k in this paper avoid the unreliability that is caused by failure mode.The longitudinal shear bond strength is linearly associated with shear-span ratio.The results provided by these two methods have a good agreement with those obtained from the tests.(3)The deflection during elastic phase can be accurately predicted by some current stiffness formulas.If the separation of the test specimen is not obvious,the formula based on GB50017-2003 can be used to predict deflection in normal service phase,but results is conservative.(4)The finite element model of composite slabs in which shear-bond slip between profiled and lightweight aggregate concrete was considered was established by ABAQUS.The numerical results have a good agreement with ones from the tests. |
