The Experimental Study Of Coupling Of Rice Husk And Geopolymer As Thermal Insulation Materials For Buildings

Industry,transportation and construction are three main parts of energy consumption in China.With the rapid development of social economy and the improvement of people's living level and working environment,the building energy consumption is increasing.It is estimated that building energy consumption accounts for 33%of total energy consumption in China by 2016,which makes saving building energy an urgent requirement for our society.It is one of the important ways to achieve the building energy saving by improving the thermal insulation performance of building envelope to reduce the loss of cooling or heating load in building,such as adding thermal insulation materials.At present,there are two kinds of building insulation materials widely used.The organic thermal insulation materials,such as Polystyrene foam,polyurethane foam and phenolic foam,they have low thermal conductivity and good thermal insulation effect,but with poor fire resistance performance and hidden danger;the inorganic thermal insulation materials,such as glass wool,rock wool,and aerated concrete,they have good fire resistance performance,but with poor thermal insulation effect.Therefore,the development of a green,safe,environmentally friendly,energy-saving and renewable novel building insulation material has attracted more and more attention of scholars.In order to achieve the above purpose,in this study,rice husk and geopolymer are used as the raw materials,and a novel energy saving thermal insulation material for buildings is developed by combining experiment and theory methods.The main contents of the research and results are as follows:1.The completion of experiment on optimum selection of raw material ratioSpecific experimental ratio:the total mass of rice husk and metakaolin is 100g;rice husk content is 0,5%,10%,15%,20%,25%,30%,35%,40%,45%,and 50%,respectively;the dosage of hydrogen peroxide is 0,1%,2%,3%,4%,and 5%,respectively;the mass ratio of sodium silicate to solid sodium hydroxide is 5.46(n=1.2);the total mass ratio of water to rice husk and metakaolin is 50%;the mass ratio of the stabilizer and the metakaolin is 5%.2.The determination of the process of material and sample preparationFirstly,mixing the rice husk and metakaolin proportionally;secondly,adding the alkali activator and mixing;next,adding water,hydrogen peroxide and stabilizer sequentially and continuing to mix,pouring paste into the mold after a certain time;finally,demoulding after 1d at room temperature,curing 2d at 70?,that is,the sample is obtained.3.The measurement and analysis of the performance of experimental samplesThe performance parameters include density,thermal conductivity,high-temperature resistance,compressive strength,water absorption and moisture content.It was tested and the test data are analyzed.The experimental results show that,for the composite insulation material with different rice husk content,the thermal conductivity is less than 0.12W/(m.K)when the rice husk content is 0-20%and 35-50%,the density is 0.33-0.47g/cm3 and 0.32-0.41 g/cm3 respectively,and the compressive strength is 0.91-2.59MPa and 1.33-1.39MPa respectively;for the composite insulation material with different hydrogen peroxide dosage,the thermal conductivity reaches the minimum(0.097W/(m.K))when the hydrogen peroxide dosage is 2%,the density is 0.41 g/cm3 and the compressive strength is 2.59MPa correspondingly.In this study,the composite insulation material of coupling rice husk and geopolymer has not only light weight,good thermal insulation and compressive strength,but also pollution-free and low cost.Meanwhile,it also achieves the waste utilization and has a good application prospect in the field of building thermal insulation.