Research On Toughening And Lighting And Preparation Of Cement-based Foamed Insulation Material

Global energy consumption surged rapidly bring about the energy shortage problem, so the energy conservation and emissions reduction has become a research topic in the world. Our country building energy consumption accounts for a third of the total energy consumption, including building exterior energy loss is as high as 40%~ 45%, the proportion of building energy efficiency as the most direct and the most potential energy saving way has attracted extensive attention of the whole society, building external wall thermal insulation material is in focus. The foamed plastic with its light weight and low thermal conductivity occupied larger market share, but they are easy to cause fire disaster. Based on external wall thermal insulation material research status, this paper intends to develop a new foam insulation material which use inorganic gelled material as the basic material, modified by adding admixtures to overcome the defects of foamed concrete such as brittle, water absorption, so as to acquire less weight and good toughness.This article co MPared various properties of two types of foam cement, one is Portland foamed cement prepared by hydrogen peroxide, another is foamed sulphur-aluminate cement which used rosin foaming agent by the physical foaming method. For foamed Portland cement, the best coagulant dosage was 0.4wt% and the best dosage of hydrogen peroxide solution was 5wt%, on this condition The foam specimen density was 460kg/m3, the coefficient of thermal conductivity is 0.060W/(m?K), in the same foaming magnification. For foamed sulphur-aluminate cement, the best coagulant dosage was 0.03wt%, rosin content was 2.5wt%, the foamed specimen density was 408kg/m3, coefficient of thermal conductivity was 0.050W/(m?K). Co MParison between the two foamed cement, bulk density and thermal conductivity of the latter is small. The optimum process parameters is: foam cement slurry temperature was 35℃, the mixing time was 3000r/min, stirring time was 100 s, the best dosage of foam agent was 0.4wt%.Then the paper added the secondary fly ash lightweight aggregate with obturator glass beads in order to reduce the density and thermal conductivity of foamed specimen. Grading results show that: when the beads accounted for about 25%, the air void of lightweight aggregate was the lowest, close to the theoretical value. So the ratio of obturator beads and the secondary fly ash was 1:3, the gradation lightweight aggregate coefficient of thermal conductivity tend to be 0.03W/(m?K). Blending lightweight aggregate and grading sulphur aluminate cement, when grading lightweight aggregate content was 41.3wt%, foam specimen density reduced to 285kg/m3, coefficient of thermal conductivity reduced to 0.038W/(m?K).Using modified urea-formaldehyde resin, polyvinyl alcohol(PVA) fiber, diatomite toughened the foamed cement. When the dosage of modified urea formaldehyde resin was 10wt%, the thermal conductivity of compound foamed specimen reduce to 0.034W/(m?K), the 7d compressive strength of composite foam specimen increases to 0.76 MPa, 28 d compressive strength increases to 1.27MPa; When the amount of PVA fiber was 1.5%, crushing ratio of foamed specimen decreased by 46.53%; After adding 0.5wt% of diatomite, the crushing ratio of foamed cement specimen down to 0.91, decreased by 10%.