Researching The Mix Design Of Polymer Modified Thermal Insulation Mortar And Its Testing Method

At present, organic insulation materials is mainly used in China's exterior insulation system. Although this type of insulation material has good insulation properties, it has poor weatherability, vulnerable aging, and the existence of 25 years constraints.Compared to organic insulation materials, inorganic insulation mortar has a higher strength, durability and fire-proof,which offers good comprehensive performances and green environmental protection, its popularization and application particularly suited in cold winter and hot summer areas. However, its application time is short, and the corresponding systematic research lacks, it is necessary to carry out the system of research, to develop appropriate standards to provide technical support.This paper uses Portland cement as the main cementing material, glazed hollow bead for the aggregate, with fly ash, calcium hydroxide, fiber, cellulose ethers and latex powder, to develope the mortar with mineral binder and using lightweight inorganic granule as aggregate; research the factor which impact the thermal conductivity and the impact of test conditions.This paper studies the effect of each component when the mix amount of mix amount changes. The results show that: With the amount of glass beads increasing, dry density and thermal conductivity decreases, shrinkage rate decreased,too; the suitable amount of fly ash and calcium hydroxide, can improve the workability of the mortar ; Latex powder increase the tensile bond strength and reduce shrinkage; appropriate amount of cellulose ethers fresh mortar can improve the performance of construction, reduce insulation mortar shrinkage;the fiber can improve the tensile bond Strength.Two reasonable ratio of inorganic polymer light-weight thermal insulation mortar was determined by the research.The thermal conductivity of I mortar is 0.0689 W / m·K, compressive strength reached 0.98 MPa, tensile bond strength to 211 kPa, softening value of 0.71, compared GB/T20473 I mortar compressive strength of 390 percent increase, raising softening coefficient 42%;the thermal conductivity of II mortar insulation for 0.0803 W / m·K, compressive strength reached 1.41 MPa, tensile bond strength to 320 kPa, softening value of 0.74, compared GB/T20473 II mortar increase of 252 percent strength, Softening coefficient increased 48 percent. This paper provides technical support for the new local standard of Zhejiang. Mortar holding the scanning electron microscope and found: cement hydration products and the formation of a polymer IPN structure, thermal insulation mortar aggregate and cement paste interface more closely connected. After the morphology analysis: cement hydration products and the formation of a polymer IPN structure, the aggregate and cement paste interface more closely connected.The thermal conductivity is an important indicator of insulating mortar, so far the research of mortar insulation thermal conductivity is little. In this paper, the quantitative relationship of the inorganic polymer light-weight thermal insulation mortar dry density and thermal conductivity has been established , and determining the thermal conductivity of insulation mortar revised to 1.2,by the curves of the thermal conductivity and moisture content.To Determine the mixture ratio by considering the Composite performance of the thermal insulation mortar. Test result shows that the performance of the thermal insulation mortar met standard requirements.By examining the conditions of insulation mortar and the test results, the more reasonable Conservation approach is determined:, 14 d parcels conservation and 14 d standards conservation in 20±3℃, relative humidity of 55% -65%;It is found that broken glass-bead volume will increase if stirring time is more than 3 min, and dry density increase;The softening coefficient of thermal insulation mortar reaches the minimuminin when the water soaking time is 24 h. This paper also found that the methods of antifreeze test which provided by GB/T20473 is not suitable for thermal insulation mortar, and set a reasonable test method.