Preparation And Properties Of Gypsum-Based Exterior Wall Thermal Insulation Materials

There are many kinds of building insulation materials on the market at present, but little can meet the requirements of non-combustion, volume stability, firm bonding for the external wall insulation system. The influence of composite additives made of soap powder, cement, air entraining agent and aluminum putty on the setting performance, water resistence,strength and thermal insulation property of foam gypsum were studied by orthogonal and single factor experiments. Through the experimental research explore the principle and method of preparing the external wall insulation materials which have Water resistance, heat preservation and fireproof performance. Through the above work, The main research results are listed as follows:1.Composite additives not only can produce a moderate bubbles, and can adjust the setting performance of gypsum effectively. soap powder has biggest effect on the initial setting time, followed by cement, again is the air-entraining agent, aluminum paste is smallest. When the composite additives for cement is30%, soap powder is0.35%, and air-entraining agent is50%, aluminum paste mixing ratio1/2600, the comprehensive properties of gypsum is better, its initial setting time is33minutes, final setting time of48min.2. Soap powder has significant effects on the strength of the foam composite gypsum, with the increase of soap powder content foam composite gypsum strength dropped substantially, but greater than0.3Mpa, it meets the requirements of thermal insulation materials on the strength. Cement, air-entraining agent, aluminum paste has little influence on the strength of foam composite gypsum.3. Composite additives can effectively improve the water resistance performance of gypsum, the softening coefficient of foam gypsum modified by composite additives distribution between0.50-083, and the influence of four factors is soap powder> aluminum paste> cement> air-entraining agent, soap powder has the most significant influence on the water resistance of gypsum. With the increase of soap powder, softening coefficient of gypsum increase. with the increase of cement, air-entraining agent, aluminum powder, the softening coefficient of gypsum changes different.4. Composite additives can reduce the thermal conductivity of foam gypsum and increase the thermal insulation performance. The thermal conductivity of foam gypsum modified by composite additives distribution between0.129w/m.k-0.088w/m.k. The influence of four factors is soap powder> cement> aluminum paste> air-entraining agent. So soap powder is main foaming agent.5. When the composite additives are made of cement of10%, soap powder of0.38%, air-entraining agent of100%content and aluminum putty of1/2600ratio, the foam gypsum has a better comprehensive performance, namely, the flexural strength is0.50Mpa, the compressive strength is0.83Mpa, wet strength is0.47Mpa, softening coefficient is0.57, dry apparent density is630kg/m3, coefficient of thermal conductivity is0.077W/k.m. It has a better comprehensive performance.