Experimental Study About Concrete Composite Slabs With Additional Bars

Since the composite slab combines the superiorities of the cast-in-place slab andprefabricated slab, it has being developing quickly these years in our country. As thehousing industrialization continue to push forward, the advantages of the compositeslab are well adapted to the market demand. Composite structure is also increasinglyknown in social life, hence the composite slab has a good development prospect.Through the experiments of four concrete composite slabs under static loading, tocompare their flexural properties(deflection, bearing capacity, failure mode),this paperdiscusses the influence of composite slabs’ flexural behavior on different length ofadditional bars and sectional effective height. The main work and achievements of thispaper are as follows:(1)When experimenting the four composite slabs under static loading, we collectedthe ultimate bearing capacity, crack width and deflection of each composite slab. Thenthe test data was used for drawing curves to compare and analyze. The test results showthat can effectively improve the bearing capacity of the composite slab, by reasonablyincreasing the effective height of section and effectively controlling the length of theadditional bars. In addition，setting lattice bars near the midspan can integrate theconcrete and additional bars, which plays an important role in improving the integralityof the composite slabs.(2)According to Code for Concrete Structure Design(GB50010-2010),we usedformulas to calculate the deflection of four composite slabs on normal use, andcompared the calculated results and test results. The analysis results show that whenthe load was not big, the measured values were smaller than the theoretical values. It isbecause the lattice bars near the midspan restrained the additional bars, therebyrestricting the growth of the deflection. With the increase of load, the cracks inmidspan developed quickly. The flexural rigidity of composite slab in reality decreasedwith increasing bending moment, thus it made the actual deflection larger.(3)Using the finite element simulation software ANSYS, to test the four compositeslabs in static nonlinear simulation. In consideration of the short of four composite slab,the simulation should consider the self-weight of each slab. Each slab was simulated inseparated model. At first, the modeling method, stress distribution, deformation and characteristics of crack are shown in detail. Then the results of the simulation and testare compared and analyzed in this paper. Finally, the results of the simulation are ingood agreement with the experimental results.