The Structure And Experimental Study About Biaxial Stress Of Precast Steel Fiber Concrete Composite Slab

Precast steel fiber concrete composite slab is a new type pre-cast floor,composite panel is steel fiber concrete which has better performance in crack resistance and explosion protection property,it can absorb a large number of seismic energy when disastrous earthquake occurs.Composite slab core is foam concrete which has functions like thermal insulation,sound insulation and waterproofing,compared with ordinary reinforced concrete floor,it has a good developing prospect.The study of precast steel fiber concrete com posite slab is relatively less,our group has studied the mechanical behavior of one-way slab of it.Comparison and analysis of mechanical behavior are made between two-way slab with joint and monolithic casting two-way slab by contrast experiment,and the finite element stimulating calculation is also finished in the text.In order to figure out the problem of the large space building and improve the whole performance of floor,it is necessary to connect one-way slab by joints to form large size twoway slab,so a safe and reliable joints connection technique becomes the key technology link.Contrapose several different joints structure type of precast steel fiber concrete composite slab,experimental study of two-way slab with joints are presented in the text,Equivalent bolted connection method is put forward and comparison and analysis of mechanical behavior are also made among two-way slab with different joints by contrast experiment of traditional lap weld joints,rod welding joints and three kinds of new type joints,that is steel plate joints,bolted connection joints,plug-in anchorage joints put forward in the text,the main research content and conclusions are as follows:(1)Experimental research on bidirectional loading performance of precast steel fiber concrete composite slab is carried out in the text,tests shows that precast steel fiber concrete composite slab has good bidirectional loading performance,and its biaxial stresses state is similar to the normal concrete two-way slab.(2)Experimental research on cube compressive strength,axial compressive strength,elasticity modulus,Poisson's ration are carried out in the text,providing some reference about material property of steel fiber concrete for the finite element modeling of precast steel fiber concrete composite slab.(3)The simulation calculation is conducted for the precast steel fiber composite slab by finite element system,and the result is analyzed comparing with test results,indicating that mechanical behavior of precast steel fiber concrete composite two-way slab such as crack,deflection,bearing capacity can be simulated by finite element software to a certain extent,it can provide theoretical basis for the practical application of precast steel fiber concrete composite two-way slab.(4)Equivalent bolted connection and plug-in anchorage technology are put forward in the text by the flat-fell seam connection test of precast steel fiber concrete composite slab,and the structure type of bolt connector and its design method is also put forward in the text.(5)For the first time plug-in anchorage is lead up to the flat-fell seam structure form of floor,compared with the traditional join-colligation,it has clear path for force transfer and it will not cause cracks in the lapping zone when pouring concrete,above all its simple construction,and tests shows that plug-in anchorage can be applied to precast steel fiber concrete composite slab.