Preparation And Basic Performance Studies Of Recycled Plastic Foamed Concrete

With China’s extensive development of the rapid expansion for a long time,environmental problems are increasingly prominent and pollution is more and more serious.The blue sky and white clouds,green hills and clear water of the former days disappeared gradually because of the aggravation of pollution.The national haze outbreaking every year after the winter is also revealing the seriousness of China’s environmental pollution and the fragility of ecology.To implement sustainable development and reduce the damage to the ecological environment has become the inevitable way for China to survive and develop in the future.Foamed concrete as a new type of wall insulation material,not only products with low energy consumption,but also can make use of industrial waste,reduce the buildings’ energy consumption of cooling in summer and heating in winter because of its excellent insulation properties,so it conforms to the future direction of low carbon and energy consumption and green building materials.Plastic is one of the indispensable material,but these waste plastic can’t be natural degradation and will also bring pollution to the environment only relying on burning or landfill.Recycled waste plastic cleaned and broken into particles by researchers at home and abroad were mixed into the concrete for performance research,which opened up a new way for the recycling of waste plastics.In this paper,recycled waste plastic was incorporated into foamed concrete as a lightweight aggregate,and the research on its preparation and basic properties was carried out.The main research results are as follows:(1)The effect of stirring rate,stirring time and admixture content(water reducing agent and foam stabilizer)on the performance of recycled plastic foamed concrete in the physical foaming process was studied by single factor test,and then the mix proportion was determined.In addition the range of multiple factors of subsequent orthogonal test was determined by the foaming agent test and the plastic content test.The result indicated that the stirring rate of the foaming agent diluent is 500 r / min preferably,and the stirring time is not fixed at the optimum value,which is related to the amount of the foaming agent added.The optimum content of water reducing agent and foam stabilizer is 1.25% and 0.04% respectively.(2)The effects of plastic type,plastic content and foaming agent content on the dry density,water absorption,compressive strength and thermal conductivity of recycled plastic foamed concrete were studied by orthogonal test.The results showed that the effect of foaming agent on the performance is more significant than the effect of plastic type and plastic content.The dry density,compressive strength and thermal conductivity decrease with the increasing of the amount of the foaming agent,and the water absorption continues to rise.In the case of increasing the amount of plastic,the dry density and compressive strength curve first increase and then decrease,while the water absorption and thermal conductivity show the opposite trend.When the plastic content is 15%,the comprehensive performance of the test block is the best.Among the five kinds of plastics,the range of dry density of the test block added ABS increase greatly and the other properties are strengthened too.The different properties of the test block respectively added HDPE,MDPE,unmodified PP and modified PP are changed.After the comparison,the performance of ABS is the best.(3)The relationships of dry bulk density and compressive strength,dry bulk density and porosity,thermal conductivity and dry bulk density of recycled plastic foamed concrete are obtained by curve fitting,and based on the results of thermal insulation test data,the three-phase thermal conductivity model of recycled plastic foamed concrete is deduced and verified.