Research Of Vitrified Expanded Perlite Thermal Insulation Mortar And Insulating System

Made of cement as the cementious material, expanded polystyrene granule or ex-panded perlite as the thermal insulation material, the traditional insulation mortar, for large shrinkage , produce cracks in itself easily. Due to high water absorption, expanded perlite insulation mortar is not recommended or forbidden in many building construc-tions. Expanded polystyrene granule is flammable, resulting in poor fire performance of insulation mortar, and UL flame class is only B. Substituting vitrified expanded perlite for expanded polystyrene granule, using gypsum and cement as cementitious materials, modifying prosperities with redispersible powder, cellulose ether and polypropylene fiber, this thesis research the inorganic thermal insulation mortar ,which meeting the standard GB/T 20473-2006, to solve cracking and poor fire performance of traditional thermal insulation mortar. This paper also studied gypsum plaster for finish coating which mating gypsum-based insulation mortar, and interface treating agent and finish-ing coat mortar which mating cement-based insulation mortar. Referring to JGJ158-2004, the external thermal insulation system was tested.The results show that the initial setting time of gypsum is only 10 minute and the operating time is very short. Mixed in 0.1% citric acid, the initial setting time extended to 0.5 hours and final setting time extended to 2 hours. Operation time was greatly ex-tend and could satisfy the construction requirements. Because the properities of cement-based thermal insulation has large surplus according to GB/T 20473-2006, part of cement can be replaced by admixture. The volume of fly ash to replace 30%, compressive strength and bond strength are still capable to meet the standards. Substitution of 30%, the compressive strength is less than 0.2MPa, Shear bond strength is close 50KPa, strength below standards. When ash calcium powder replaced a small amount cement, the ratio of compressive strength and flexural strength and brittleness of mortar was reduced, so that the cracking resistance increased. While exceeding 10%, the ratio of compressive strength and flexural strength and brittleness increased.When the aggregate and cementitious material ratio reaching 4.5L~5L: 1Kg,dry density of mortar meetsⅡ-type mortar requirements of GB/T 20473-2006, and when reaching 7L~7.5L: 1Kg, meetsⅠ-type mortar requirements. Redispersible powder can significantly improve bonding strength of thermal insulation mortar. Bonding strength has linear relationship with the content of redispersible powder. According to gyp- sum-based mortar, when the content of redispersible reaching 2%, bonding strength can excess 50KPa, meeting requirements of GB/T 20473-2006. Cellulose ether can increase the consistency and maintain the water of mortar, so that segregation can be prevented and uniform plastic body can be attained. When the content of cellulose ether increasing from 0 to 0.6%, water retention rate increased from around 60% to 90% above. Polypropylene fibers arranged in the stray mortar, can digest the internal contraction of the stress in all directions, thermal insulation mortar toughness and crack resistance has been greatly improved, as the role of the fiber network connection. 56d linear shrinkage of thermal insulation mortar significantly lower with Polypropylene fiber content increasing. When reaching 0.6%, the lowest linear shrinkage of mortar was attained.Based on the study, the proportioning of gypsum-base and cement-base inorganic thermal insulation was determindered. For typeⅠgypsum-based insulation mortar , gypsum: vitrified expanded perlite: citric acid: redispersible powder: cellulose ethers: polypropylene fiber was 1000: 0.05: 820: 20: 6: 6, and for typeⅡ1000: 0.05 :530 :15: 6: 6. For typeⅠcement-based insulation mortar , cement: fly ash: ash calcium powder: vitrified expanded perlite: redispersible powder: cellulose ether: polypropylene fiber was 850: 100: 50: 880: 15: 6: 6, and for typeⅡ800: 150: 50: 590: 10: 6: 6.The operating time, water retention, compressive strength, flexural strength and bond strength performance of preparation of gypsum plaster for finish coating met the relevant requirements of JC/T 517-2004. The adhesive strength and ratio of compressive strength and flexural strength of preparation of interface treating agent and finishing coat mortar, the relevant requirements of performance met JGJ 158-2004. Preparing typeⅡinsulation cement-based mortar and supporting interface treating agent and fi-nishing coat mortar, the composed inorganic thermal insulating rendering system met the requirements of JG 158-2004.Inorganic thermal insulating rendering system is suitable for the region of hot summer and cold winter and the region of hot summer of and warm winter. 10~40mm thick inorganic insulation mortar can make heat transmission coefficient of exterior wall in 2.0~1.2 W/(m~2·K), and material fees is 13 ~ 32 RMB/m~2.