Study Of Mechanical Performance Of Thin-walled Beams With Openings–to-Lightweight Aggregate Concrete Composite Slabs

Steel-concrete composite slab has been more and more widely used for its advantages ofhigher bearing capacity and stiffness, better ductility and energy-dissipating capacity. Comparedwith the profiled sheet concrete composite slabs, the thin-walled beams with openings-to-lightweight aggregate concrete composite slab studied in the thesis has the characteristics of lighterweight, higher strength, less wet work and being convenient for construction. Therefore, study ofthe mechanical performance of the thin-walled beams–to-lightweight aggregate concretecomposite slabs not only has important theoretical significance but also has the extensiveengineering application value. But there is fewer research work on the new type of composite slabsnow, and there is no research report on the fundamental study of the slab presented here.The composite slabs of thin-walled beams lightweight aggregate concrete is taken as theobject of study in the thesis, the mechanical properties of the composite slab before and after actionof impact was experimentally studied and analyzed. Firstly, static load tests of eight of thecomposite slabs before and after the impact action was finished, and effects of factors such asdifferent shear constructional measures, load types and impact values on the mechanical propertiesof the specimens have been analyzed. Then the numerical simulation computation of mechanicalproperties of the composite slabs after impact action was carried out with the software of Ansys,and was compared with the experimental results.The results show that the thin-walled beams lightweight aggregate concrete composite slabshas higher bearing capacity and deformation capacity. The main failure form is the longitudinalshear failure. The failure reason of the slabs mainly was the weak bond strength between theconcrete plate and the steel beam after impact action, which cause larger slip between steel beamand concrete slab, and so the two parts of the composite slabs loss the combination effect. For thesame conditions, the single factor effect on the performance of the composite slab as follows:(1) Ifthe precast slab has embossing, the slotted spacing is smaller, and the shear keys has better bondingstrength, the composite slab has better mechanical performance.(2) The impact action is bigger,the mechanical performance of the composite slabs is much worse, and this trend increases withthe impact action.(3) Effect of the impact action on the composite slabs declines from the positionwhich is1/4L away from the end to both ends of the composite slab.(4) According to the calculation method of the ordinary concrete composite beams, the formula of deformation andstress of the new composite slabs consisting of thin-walled beams with openings and lightweightaggregate concrete has been put forward considering the slip effect.(5) The simulation resultspresented in this thesis agree well with the test results.