Study On Performance And Experimental For The Assemble Monolithic Concrete Composite Slab With Reserved Cast-in-site Belt On Simple Supported All Four Edges

The assemble-monolithic concrete composite slab with reserved cast-in-site belt is developed by the combination of the cast-in-place concrete floor and the reinforced concrete waffle slabs.This kind of slab is made of Cast-in-site belt and the prefabricated slab.The difference between this slab and other concrete waffle slabs is that this slab is connected by reserved steel bar,after lifting,transportation and the cast-in-site concrete pouring work,the prefabricated slabs are assembled as a whole.The advantage is that modular design could be applied into this slab and could assembled according to the actual requirements.So this slab not only has the advantage that high integrity,good efficiency,short duration of cast-in-place concrete floor,but also has the advantage of easy Installation.It can be seen this slab has a good prospect.In this paper,the main work is divided into three parts:First,the displacement of the overall system has been established,Internal force calculation method of slab is deduced,determine the design method of the floor.Second,depend on static load test for three floor specimens under uniformly distributed load,research the force form of floor slab and the development law of crack.And the test results are compared with the same size of the cast-in-place reinforced concrete floor specimens for comparison and analysis,validation of the floor bearing capacity and the applicability of the calculation theory.Third,the floor bearing capacity and the applicability of the theory of computation has been verified by creating floor model with finite element software,parameter analysis of test floor has been conducted and more perfect internal force calculation method is put forward.The specific research result is as follows:(1)This new floor slab have advantage for the construction of convenient transportation,production,assembly,convenient and so on.(2)Depend on static load test for three floor specimens,we get conclusion:as load from zero to normal use load stage,there is no crack and floor slab has good overall performance;Continue the test,as the load is more than the normal use of the load,cracks between plate and cast in place appear;As the load continues to increase,cracks between plate and cast in place sustained development,the crack extend to the plate;In the late stage of loading,the floor cracks develop to the two sides of the cast strip,development to the floor four corners.From the experimental phenomena,we can conclude that precast plate and the cast strip can work together,the floor has two-way force characteristics.(3)Based on the experiment,make comparative analysis to the two parameters of theory of internal force calculation and floor assembly form,both the whole displacement field theory and the theory of the beam structure calculation of the floor slabs are not produced crack in the(4)normal use stage.The bearing capacity of the specimen under the whole displacement field is slightly lower;Analysis of floor specimen under two kinds of assembly forms,as the steel plate arrangement along the short span precast floor length.The bearing capacity of the floor slab can be improved by connecting the two prefabricated plate through the steel in the long span direction.(5)Parametric finite element analysis has been conducted.The specimen used Six prefabricated plates are assembled in the form of a test piece.Plate dimensions are 800 x 800mm,1000 × 1200mm,1000mm × 1200mm.Comparison of the cross load displacement curve between the slab test and the finite element simulation,within the elastic range,The results of the experiment are in good agreement with those of the finite element.Comparing the simulation results of three kinds of floor model,we found that with the increase of the size of the prefabricated plate,the bearing capacity of the floor has a downward trend.(6)In different form of assembly for this floor,as the short span arrangeprefabricated full-length steel,the flexural performance of the floor is greatly improved.as the short span arrangeprefabricated full-length steel,long span direction will be part of the plate through the steel link.The bearing capacity of the floor can be improved.The research above could provide a reference to the practical engineering of the assemble-monolithic concrete composite slab with reserved cast-in-site belt.