Experimental Study And Analysis On Mechanical Properties Of ECC Composite Slabs

The steel deck concrete composite slab is a new type of composite structure.It can make full use of the materials character which steel is good at tension and concrete is good at compression.Compared with reinforced concrete slabs,it has high bearing capacity,high stiffness,good seismic performance.Because of the above advantages,its application in our country high layer buildings is widely.Engineering fiber reinforced cement composite ECC(Engineered Cementitious Composites)is a kind of high toughness and ductility of concrete.Compared with ordinary concrete,it has the advantages of light weight,good tensile strain hardening performance,Strong ability to cooperate with steel deformation,and strong ductility etc..ECC material itself without coarse aggregate,and mixed with fiber,so when after cracking,the cement matrix tensile stress through the bridging effect directly to the uncracked part.Therefore,the ECC material has the typical multi seam cracking characteristic,compared with the concrete cracking is bad.With the ECC material instead of the ordinary concrete in the composite floor,the performance of the composite floor can be more effective.At present,there are many researches on the mechanical properties of the composite floor slab in our country,and there is little research on the ECC composite floor.Based on the excellent properties of ECC material,in this paper we select YX-76-344-688 profiled steel plates,which is commonly used in engineering,and make a total of ten ECC composite floor slabs and two composite slabs(comparison)full-scale specimen.The mechanical properties and failure mechanism of composite slabs are studied by means of two point loading test.Mainly considing the influence of mechanical properties of the ECC composite slab,such as shear span,end stud,transverse shear reinforcement,steel plate thickness and height of composite slabs etc..In addition,the steel plate strain and concrete strain in the process of stress are analyzed,and the relative sliding of the plate and the deflection of the specimen are measured.Based on the test data,the factors that affect the bearing capacity and bond performance of ECC composite slab are analyzed.Because of the assumption of full plastic bearing capacity is based on the assumption that the concrete in the tensile zone is not involved,but the ECC material has good tensile strain hardening properties.It is necessary to consider the role of ECC in the tensile zone,so the formula of the normal section bearing capacity of ECC composite slab is introduced..And according to the test data,the formula of longitudinal shear bearing capacity is established.Finally,the finite element model is used to compare the bending failure test and the finite element load deflection curve.The results are in good agreement with each other,and the bending performance of profiled steel sheet-ECC composite slabs is analyzed by varying parameters in this way..