Study On Shrinkage Performance Of New PC-GRC Composite Wallboard

At present,there are some problems in the construction,structure and decoration of assembled concrete buildings,such as low degree of integration,production and construction efficiency of components,which are mainly embodied in the production process and low efficiency of traditional thermal insulation composite wall plate system.This seriously affects the efficient production and construction of assembled concrete building wall panels.Therefore,this topic focuses on the production of integrated prefabricated wall panels.A new type of PC-GRC composite wall panel is developed by introducing a new GRC(fiberglass reinforced cement)material and combining it with concrete.The research content of this paper is mainly aimed at the shrinkage deformation of GRC materials and concrete,because the dry and wet changes of GRC materials and concrete,temperature changes and water content changes are not the same,so this paper focus on solving the problems of easy cracking and connection of GRC materials and concrete from the material properties,connection mode.This paper first introduces the material properties of GRC and concrete,and then carries on the shrinkage performance experiment of the new PC-GRC composite wall board,the test object mainly includes a single block pure GRC wall board,a single piece of pure C30 concrete wall board,a different thickness of GRC composite wall board(15mm,10mm)and different interface connection mode composite wall board(Flat,rough surface connection,wire mesh connection).The experimental results show that:(1)The surface strain of composite wall plate and the strain of internal concrete appears obviously lower than that of single material,that is,the crack resistance of composite wall plate is obviously better than that of single material wall plate.(2)By comparing the experimental data of composite wall board with different thickness of GRC decorative layer,it shows that when the thickness of GRC decorative layer is 15 mm,the shrinkage strain of GRC material is reduced by 52% and the shrinkage strain of concrete is reduced by 72%.When the thickness of GRC decorative layer is 10 mm,the shrinkage strain of GRC material is reduced by 22% and the shrinkage strain of concrete is reduced by 17%,which indicates that the crack resistance of GRC decorative layer using 15 mm thickness composite wall plate is obviously better than that of GRC decorative layer using 10 mm composite wall plate.(3)By comparing the experimental data of composite wall plate with different interface connection modes,it can be seen that when the interface is connected by flat connection,the shrinkage strain of GRC material is reduced by 52%,the shrinkage strain of concrete is reduced by 72%.When the interface is connected by rough surface,the shrinkage strain of GRC material is reduced by 58% and the shrinkage strain of concrete is reduced by 24%.When the interface is connected by wire mesh,the shrinkage strain of GRC material is reduced by 40%,and the shrinkage strain of concrete is reduced by 64%.Comparing the data of three groups of connection modes,it can be seen that the influence of different connection modes on the shrinkage performance of concrete is more obvious than that of the shrinkage performance of GRC materials,and the split interface is more effective than that of rough surface connection and wire mesh connection to improve the crack resistance of composite wall plate.Finally,the finite element simulation is carried out by ABAQUS software on the basis of this experiment.The results show that the time-strain curve of finite element simulation is basically consistent with the change trend of time-strain curve of test monitoring.By comparing the simulated data with experimental data,it shows that the maximum error of the test value and the simulated value of the surface strain gauge of the S3?S6 specimen is 5.7%,the minimum error is 0.1%,and the average error value is 3.9%,which is lower than the control error 10% under normal conditions.The maximum error of the test value and the simulated value of the embedded strain gauge of the S3?S6 specimen is 9.4%,the minimum error is 0.1%,and the average error value is 4.8%,which is lower than the control error 10% under normal conditions.it indicates that the finite element model results are reliable.and on the basis of this finite element model,the size expansion of the new PC-GRC composite wall plate and the stress distribution law of the composite wall plate can be studied.The results of this paper provide valuable reference for the application of the new PC-GRC composite wall plate in practical engineering.