| Nowadays,the exterior wall protection system of traditional prefabricated buildings has problems of low integration,cumbersome installation procedures and low construction efficiency in exterior wall decoration,and is prone to cracking,which seriously threatens people’s lives and property safety.It is seriously inconsistent with the development requirements of China’s construction industrialization.In the context of China’s policy of vigorously developing prefabricated buildings,this paper relies on the research sub-project of the 13 th Five-Year National Key Research and Development Program and proposes a new PC-GRC composite wall panel that combines load-bearing and decoration.The surface of the layer is compounded with a GRC decorative layer with excellent performance,rich texture and changeable shape,to achieve the integration of prefabricated decorative wall panels in assembled buildings from factory production to on-site construction and installation.PC-GRC composite wallboard is a wallboard composed of two materials with different properties.The difference in shrinkage properties between the two materials is the main cause of cracks in PC-GRC composite wallboard,which seriously affects the composite wallboard.Enclosure function and decorative effect.In the past,most of the research on the shrinkage performance of composite wallboards was mainly for the test and analysis of a single material wallboard,ignoring the impact of the interaction between the composite materials on the shrinkage performance.On this basis,this paper takes this new type of PC-GRC composite wallboard as the research object,and discusses and analyzes the shrinkage performance of PC-GRC composite wallboard through a combination of experimental research and numerical simulation.The contents are: 1)Free shrinkage performance of two single materials of concrete and GRC 2)Comparison of shrinkage performance of PC-GRC composite wall panels of different sizes with free shrinkage performance of single materials 3)PC-GRC composite wall panels of different sizes Comparison of shrinkage performance between 4)The shrinkage performance ofPC-GRC composite wallboard is finite element simulated,and compared and analyzed with the test results.The specific work and conclusions of the thesis research are as follows:(1)By pouring a pure GRC material wall panel with a size of 1000 mm * 1000 mm and a pure concrete material wall panel with a size of 1000 mm * 1000 mm,and subjecting these two single material wall panels to 90-day free shrinkage strain Data monitoring and analysis,the test results show that the free shrinkage deformation of GRC is significantly greater than that of concrete.(2)By pouring a PC-GRC composite wall panel with a size of 1000 mm * 1000 mm,a PC-GRC composite wall panel with a size of 1000 mm * 2000 mm and a PC-GRC composite wall panel with a size of 2000 mm * 2000 mm,The three composite wall panels were monitored for 90 days of free shrinkage strain data,and the test results were compared with the free shrinkage strain of a single material wallboard.The results show that the combined effect of GRC and concrete on the respective shrinkage properties of GRC and concrete Both have an effect,and have a more significant impact on the shrinkage performance of GRC;where the wallboard size is 1000 mm * 2000 mm,the composite wallboard has the best shrinkage performance and is least likely to crack.(3)Comparing and analyzing the shrinkage deformation of PC-GRC composite wallboards with different sizes,the results show that the shrinkage deformation of the GRC decorative layer and the concrete structure layer in the composite wallboard increases with the size of the composite wallboard Among them,when the size of the wallboard is1000 mm * 1000 mm,the overall shrinkage deformation of the composite wallboard is the smallest;when the size of the wallboard is 2000 mm * 2000 mm,the overall shrinkage deformation of the composite wallboard is the largest.From the perspective of the growth rate of shrinkage strain of each composite wallboard,the size effect of the composite wallboard has little effect on the shrinkage performance of the surface GRC decorative layer,and has a greater impact on the shrinkage performance of the concrete structure layer.(4)The finite element analysis method of "equivalent temperature difference" was used to simulate the shrinkage strain of PC-GRC composite wallboards of different sizes,and compared and analyzed with the test values.The results showed that the composite wallboard simulation values and tests The values are basically consistent,which further verifies the rationality of using the "equivalent temperature difference method" to analyze the shrinkage strain of the composite wallboard and the reliability of the test results.Figure [84] table [11] reference [51]... |
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