Experimental Research On The New-type Silicate Thermal Insulation Material For Wall

Energy consumption in China is considerable. Especially with the rapid development of economy and tremendous population growth, the demand of building area is becoming more and more larger. So building energy consumption of resources has become an increasingly important issue. To reduce the use of building energy consumption, the thermal insulation effects of building wall, roof, floor, window and door are very important. And60%of the building structure wall retaining structure is the main parts of heat transmission, with largest proportion of the energy consumption. So the key to building energy efficiency is how to make the wall having good heat preservation performance. And the development of new-type insulation material for wall has serious social and economic benefit.In this study, sepiolite fibers, expanded perlite, alumina fibers and portland slag cement were main raw materials. And a kind of new-type silicate thermal insulation material for wall was prepared by them. According to the porous structures of sepiolite fibers and expanded perlite, they should be treated with acid activation and hydrophobic modification, respectively. The apertures of sepiolite fibers were expanded when it was acid activated by hydrochloric, increasing the porosity. And the hydrophobic treatment was conducted with the expanded perlite by methanesiliconic acid sodium salt to raise their hydrophobicity, with the decrease of thermal conductivity. Both of the activated sepiolite fibers and expanded perlite had low thermal conductivity, improving the insulation effect of thermal insulation material. Sodium hexametaphosphate ((NaPO3)6) and polyacrylamide (PAM) were dispersing agents, dispersing a certain amount of modified sepiolite fibers and alumina fibers, respectively. After they came into being homogeneous dispersion system, some hydrophobic expansion perlite, slag portland cement and foaming agent were added. Then stirred and dried the compound to obtain silicate thermal insulation material for wall. The addition of sepiolite fibers, expanded perlite, alumina fibers and the water cement ratio affected the performance of the heat preservation material, which included heat conductivity, compression strength and volume-weight. According to this, we used orthogonal experiment to analyze the best composition proportion to prepare the new-type silicate thermal insulation material for wall. The results show that when the quality ratio of sepiolite fibers, expansion perlite, and alumina fibers were25%,32%and5%, and the water cement ratio of0.60, respectively, the material had low thermal conductivity and high compression strength. And the optimum thickness of thermal insulation material for wall was35mm. The thermal conductivity measuring apparatus measured the heat conductivity of the new-type silicate thermal insulation material for wall0.055W/(m·K), and the compression testing machine measured the compression strength2.1Mpa. The water absorption and volume-weight of the heat insulating material were2.03%,200.9kg/m3, respectively.The scanning electron microscope (SEM) and X ray diffraction instruments (XRD) were used to characterize the morphology of the materials. After that, the structures, properties and mechanisms of the materials were analyzed. The silicate thermal insulation material for wall not only has low thermal conductivity and high compression strength, but also low-cost, non-poisonous and non-combustible. It will have widespread use and a great foreground.