Preparation And Application Of XPS Composite Template

With the continuous deepening of building energy efficiency, the problem of which has attracted more and more attention. China is being in the developmental stage of improving energy efficiency and reducing building energy consumption. The thermosteresis of the building envelope is as high as 70%~80% in the heat loss of building, while the thermosteresis of external wall is the largest in the building envelope. Therefore, it is an important way to reduce heat loss that the exploitation and application of external wall thermal insulation material. The beam column of the self-insulation wall needs external thermal insulation, China has emerged a wide variety of external thermal insulation methods of the beam column. The XPS(Insulated with extruded polystyrene foam) composite board with excellent thermal insulation and mechanical performance can be used as both the external insulation wall and the template of the concrete beam column.In this paper, the mechanical properties of XPS composite were studied, including bending strength, compression strength and tensile strength. In order to improve the comprehensive mechanical properties of XPS composite template which can be applied to the exterior wall formwork, two kinds of strengthening measures, cement mortar dark column and plastic connecting bolt are adopted based on the traditional plate.According to the JGJ162-2008 "technical code for the framework", the bending strength of three kinds of plates was measured respectively in the conditions of the ordinary, dark column with cement mortar and plastic connecting bolt by four point bending test method. When the bending deflection of it is 4.2mm, in the same type of the composite template, the bending strength of the plate with plastic connecting bolt is the biggest, and the cement mortar is the least.The cement mortar dark column belongs to brittle material, easy to produce stress concentration while the bond strength is tiny between cement mortar dark column and XPS insulation board.The plastic connecting bolt with a screw buckle will produce the squeeze pressure and mechanical bite force in the installation process. So it can be very helpful to fix the polymer mortar layers on both sides of the composite template to improve the bending strength of the composite template.According to the GB/T8813-2008 "the measure of compression performance of the rigid foamed plastic", the compression strength of the plate was measured by the methods of local and uniform compression. The results showed that the compression strength of the same type of composite template is the maximum and the compression strength of the ordinary was the least.Plastic anchor bolt compared to the cement mortar dark column did not produce obvious compression deformation.Tensile test was finished according to the JGJ144-2008 "Technical specification of external wall thermal insulation engineering". The results showed that the tensile strength of the same type of composite plate is the maximum, and the conventional plate is the least. Because the plastic connecting bolt with the screw buckle in the installation process will produce the extrusion pressure and mechanical bite force compared to cement mortar dark column and XPS insulation board. Therefore, the tensile strength of the same type of composite template with a plastic connecting anchor bolt is greater.The comprehensive analysis of the experimental results showed that the cement mortar can improve the compression strength and tensile strength of the plate, while the bending strength of the plate is reduced. Mainly because the cement mortar dark column belongs to the brittle material, the stress concentration is easy to be formed around it. The plastic connecting bolt can realize not only the function of pulling and anchoring, but also the function of strengthening plate in the construction stage. The XPS composite formwork can meet the demands of the lateral pressure of the concrete construction and the wind resistance performance of the external insulation material, which has obvious superiority on the technology and economy such as simple process, low cost, etc. Therefore, XPS composite template has a perfect prospect.