Research On The Properties Of Heat Preservation And Thermal Insulation Materials Used In Buildings

The construction energy conservation is a basic way to solve the energy question in our country. And the direct and effective method for energy efficiency in buildings is to use heat preservation and thermal insulation materials. Colloid powder polyphenylene grain thermal insulation mortar, EPS foam and XPS foam have become three major heat preservation and thermal insulation materials, moreover, the mono-component polyurethane foam (PU) sealing agent also becomes the main sealing and thermal insulation material used in buildings. However, it is also limited to study heat conduction performance about the above materials, lacking the data and the empirical formulas of the thermal conductivity in particular (only empirical formulas of the traditional thermal insulation materials, such as vermiculite and inflated pearlite, included in existing design handbook). So it is necessary to study the several materials in deep for improving the project quality and energy efficiency and satisfying the energy -saving design and the product acceptance testing.Research on the properties of colloid powder polyphenylene grain thermal insulation mortar: To test the main properties' changes and influence on each other during the experiment cycle (28d) ,and conclude:(1) It is discovered through the experiment that how much Water poured has tremendous influence on the density, the thermal conductivity and the compressive strength of the thermal insulation mortar. Therefore, the mortar preparation and the construction should be under the material factory's ingredient proportion and requests. (2) The main properties of the thermal insulation mortar, such as the moisture content, the thermal conductivity and the compressive strength, have remarkable changes during the experiment cycle (28d).The research indicated: the moisture content affects supremely the changes of the thermal conductivity and the compressive strength. In actual construction, it should maintain at least 14 days after the plastering procedure of thermal insulation mortar, then carries on the next step armor layer construction. Only thus can the mortar, as the heat insulating layer, fully display its good heat preservation and thermal insulation, high mechanical strength and so on. (3)After experiment, the mortar's moisture content is still high (above 10%), and is influenced by the natural environment. Therefore, the experiment data of thermal conductivity and compressive strength are very different from that of product instruction on the dry condition. So design and computation should take the scene actual data.Performance research on the mono-component polyurethane foam (PU) sealing agent: Through testing repeatedly, to determine the frequency of swaying the bucket," the best using period after swaying the bucket, as well as the best spraying column diameter. The research indicated that the best density value of polyurethane foam plate is 22～26 kg/m~3. Whereas, the densityρ<15kg/m~3 orρ>29.69kg/m~3, thermal conductivity is bigger than 0.05 W/(m·K) at the average temperature 35℃, which does not satisfy the correlation standard. Basing on the linear regression analysis to the empirical data, functions of conductivity versus temperature were obtained for PU foam boards of different density, which provides the convenience for the project survey.Heat conduction performance research on EPS foam and XPS foam: With tests and theoretical analysis about heat conduction, functions of conductivity versus temperature were obtained for different dry densities of EPS foam and XPS foam, as well as functions of conductivity versus temperature at containing certain water. To a certain extent, the test also demonstrates that there are massive unqualified products in the thermal insulation material market. Therefore, suggestion of "closing the good thermal insulation material quality and guaranteeing the project quality from the source" is given.