Experimental Study On Mechanical Properties Of Concrete-polystyrene Composite Wallboard

The concrete-polystyrene composite wall(CPCWP)plate has the characteristics of loadbearing,thermal insulation and enclosure,which can meet the needs of building for structural support,energy consumption reduction and space enclosure.In this thesis,a kind of composite wallboard which is mainly used in single-story and multi-story buildings is developed.Considering various factors such as heat preservation,load bearing,fire prevention and construction,the thickness of polystyrene board is 100 mm,the thickness of concrete surface on both sides of polystyrene board is 50 mm,the mesh size of concrete surface is 75 mm × 75 mm steel wire mesh,and the diameter of steel wire is 3 mm.The concrete surface on both sides is connected into a whole by special connectors.The wallboard can be prefabricated in the factory and cast-in-situ in the field during construction.The failure mode and bearing capacity of the composite wall plate under vertical load were studied by 8 axial compression specimens and 6 eccentric compression specimens.The influence of height-thickness ratio and eccentricity on the failure mechanism and bearing capacity of the wall plate was analyzed.The finite element analysis software was used to further analyze the stress distribution law and stress mechanism of wall panels under vertical load.Through experimental research and theoretical analysis,the following main conclusions and results are obtained:(1)The internal and external concrete surface connectors are set according to the spacing of 380 mm × 380 mm,which can not only fix the position of the steel wire mesh and ensure the thickness of the concrete protective layer of the steel bar,but also make the two layers of concrete surface and polystyrene board form the overall common force.(2)Under the axial load,the wall plate first produces vertical cracks,and finally the surface concrete is crushed,and the steel wire buckling is convex.The specimen is destroyed,and the failure position is located at the upper and lower ends of the specimen.The concrete convex phenomenon occurs when individual components are destroyed.(3)The test shows that the height-thickness ratio in the range of 7.5 ? 15 has no obvious effect on the bearing capacity of the wall plate;horizontal wire of steel mesh can effectively bear horizontal tensile stress,which plays an important role in preventing the development of vertical cracks in wall panels.(4)Under eccentric load,the wall plate produces vertical cracks at the first layer of larger compressive stress.For the specimens with larger eccentricity,the other side produces horizontal cracks.Compared with the axial compression specimens,the cracking load is generally low,and the concrete surface layer of the final specimen is crushed and destroyed.Eccentricity has a significant impact on the bearing capacity of eccentrically loaded wall panels,and the bearing capacity of wall panels gradually decreases with the increase of eccentricity.(5)By referring to the relevant research at home and abroad and analyzing the test results of this study,the influencing factors of the bearing capacity of wall panels are summarized,and the calculation formulas of the bearing capacity of wall panels under axial compression and eccentric compression are derived.(6)The CPCWP plate model was established by using the finite element software ABAQUS,and the mechanical properties of the wall plate under axial load and eccentric load were analyzed.The finite element analysis results were compared with the experimental results to verify the rationality of the model analysis and further explain and supplement the experimental results.