EPP Bearing Insulation Concrete Performance Test Research

EPP(polypropylene)load-bearing insulation concrete is a new building energy saving material.It has important practical significance for improving the thermal insulation performance of building envelope and achieving the goal of building 75%energy saving.To accelerate the practical application of new concrete materials in engineering,the preparation technology,basic mechanical theory calculation,denaturing performance and durability of EPP bearing heat insulation concrete are studied in this paper.Including the following:(1)EPP modification treatment experiment.The influence of different modification schemes on bond performance of concrete interface transition zone was studied and the optimum modification scheme was obtained.Through the SEM observation of the concrete section,it is proved that the modified treatment can greatly improve the interfacial bonding performance.(2)Experimental study on the mixture ratio of EPP load-bearing insulation concrete.The influence factors such as the amount of EPP particles,the replacement amount of tailings sand,the particle size and gradation of the EPP particles on the test indexes are studied through the orthogonal test,and the main factors affecting the content of the EPP particles are determined.Through the optimization of the mix ratio,EPP load-bearing insulation concrete mixture ratio of C20,C15 and C10 was obtained,and the preparation technology and the proportion of the composite were provided for the practical application of the project.(3)Experimental study on deformation performance of EPP load-bearing insulation concrete.The axial compression test of three strength grade EPP load-bearing insulation concrete with C20,C15 and C10 is carried out respectively.The destruction of concrete was analyzed,and the stress-strain curve was obtained.A constitutive relationship model was established.The elastic modulus and poisson ratio of three strength grade concrete were measured and the formula of elastic modulus was established.According to the test results of the compressive strength of the axial compressive strength and the cube test block,the function relation of the two functions was deduced.(4)Experimental study on antifreezing resistance of EPP load-bearing insulation concrete.The antifreeze levels of EPP load-bearing insulation concrete with three strength grade were measured.The functional relationship between the strength loss rate of C20 and C15 concrete and the number of freeze-thaw cycles was established respectively.The relationship between the strength loss rate and the mass loss rate of C20 concrete was established.The relationship between the compressive strength lossrate of C20 and C15 concrete and the water absorption after freeze-thaw was established respectively.The experimental results show that the mass loss rate of 5%can not be used as an indicator of frost resistance,and its water absorption after freezing and thawing can be used as a reference for anti-freezing performance.(5)Experimental Study on the anti-carbonization performance of EPP load-bearing insulation concrete.The change of carbonation depth and carbonation rate with the age of carbonation and the grade of concrete strength were obtained.According to the relation curve of carbonation age and carbonization depth,the coefficient of simplified calculation formula of EPP load-bearing insulation concrete was revised.(6)Experimental Study on the anti-seepage performance of EPP load-bearing insulation concrete.The seepage height of three strength grades concrete under0.2MPa water pressure was tested.The results shows that the impermeability and compressive strength are not strictly linear,but are determined by the combined effect of EPP particle content,pore structure,and preparation process.