Basic Mechanical Properties Research Of PVC Composite Plastic Formwork

Along with the development of cast-in-place concrete formwork engineering, newmaterials for formwork and template type is growing, as plywood for general use,plywood with steel frame, all-steel large formwork, among which the most widely usedwood plywood. However, using massive wood, do not conform to the national strategyof sustainable development; therefore, using new materials to replace the plywood hasbe-come an inevitable trend in the development of formwork industry. PVC compositepl plastic formwork uses wasted PVC plastics and wood powder as raw materials, theformwork is shaped by injection molding. This template has many advantages, such assimple fabrication technique, many cycles, recoverability, high cost-benefit; these ad-vantages of the template are enough to occupy the dominant position in the new temp-plate engineering.In this paper, the author summarized the study and application of new templatehome and abroad, and by a large amount of experiments, studied deeply into thematerial properties of the special formulas PVC composite plastic and the templateproperties, all this provided the theoretic foundation for the application and extension ofnew formwork engineering, the main research results of this study are as follows:(1) According to the relevant norms of plastic products and the template, the ten-sile and bending properties of PVC composite plastic materials were experimentallyinvestigated, determined the strength and elastic modulus of the same kind of materialsunder different measurement methods. The study proposed the constitutive equation oftension and bend by the relationship model and experimental data. The results showedthat, with one PVC composite plastic materials, there were a certain correlation betweenthe different relationship models rather than be same with.(2) Load simulation of the PVC composite plastic template with different supportspacing under the normal temperature condition, showed the maximum load whichthere were no residual deformation to the composite plastic. In the spacing of the supp-ort for200mm,250mm and300mm, the maximum load under witch the template hadno remaining deformation were6kN/m2,6kN/m2and5kN/m2. (3) This article investigated the reaction to the PVC composite plastic templatewhich is under the comprehensive action of load stress and temperature stress. Underthe vertical loads of5kN/m2, the data of the template experimented with temperaturecycle step by step, showed the maximum temperature which there was no residualdeformation to the composite plastic.In the support spacing is200mm, the template does not have the maximum safetemperature is60℃residual deformation. In the spacing of the support for200mm,the maximum safe temperature under witch the template had no remaining deformationwas60℃.(4) Based on the accumulation of thermal deformation which the PVC compositeplastic template had in the practical engineering and the result of the thermal experi-ments, the study analyzed the methods to solve the problem of the accumulation ofthermal deformation.