Study On The Compounding And Performance Of Anti-crack Mortar For External Thermal Insulating Rendering Systems Made Of Mortar With Mineral Binder And Using Ex-panded Polystyrene Granule As Ag-gregate

The building energy consumption occupies one third in our society. The total amount of building energy consumption in China increases year by year, the proportion in total energy consumption is increasing from ten percent to 27.45 percent. Combined with the design of energy saving outer wall in hot in summer and cold in winter areas, by comparison of exterior wall outer thermal insulation in nowadays, it is economical , rational, convenient construction and coincident energy saving to use External Thermal Insulating Rendering Systems with Mineral Binder Expanded Polystyrene Granule in hot in summer and cold in winter areas; what's more, it is the good performance price ratioto use flexible gradual releasing stress in every layer. The basic structure of ETIRS: the lateral sideof wall is constituted by interface mortar, ETIRS, anti-crack protective layer, facing layer. protective effects of crack-resistance mortar is:①avoiding insulation board aging;②avoiding rain erosion in insulation board;③improving impact resistance;④smaller steam permeability resistivity;⑤providing base for external facing. Study on anti-crack mortar is important and signality for building energy.This paper studies the effect of superfine sand and admixture for ETIRS anti-crack mortar, for increasing mortar total properties, which determines superfine sand parameters and the variety and the optimum mix amount of admixtures.①Sand resources in Chongqing is mainly superfine sand which fineness modulus is less than 1.0. The preparation of anti-crack mortar uses P.O42.5 cement, C/S is 1:2.8.②The study result displays: superfine sand is smaller fineness modulus ,larger mud content and harder; it's fineness modulus improves shrinkage , the ratio of compression strength and flexural strength (C/F) and so on. Superfine sand's mud content effect workability. Superfine sand's fineness modulus suitable range is 0.7-1.0,it's mud content is 0%-3%. Rubber powder improves flexibility;the test characterses crack resistance by fracture energy, max-deformation, caking property and so on. Rubber powder use three-dimensional Shanxi, the mixing amount is 6kg/m3which is 1.67%of cement. Fibre solves plastic shrinkage; the test characterses C/F, impact resistance;shrinkage; fracture index and so on. Wooden fibre's mixing amount suitable range is 7 kg/m3 which is 1.94%of cement. The mixing amount of Polypropylene fiber is 1-1.5kg/m3, the optimum mix amount in test is 1.3kg/m3 which is 0.36%of cement and fiber length is 9mm. Cellulose ether improves water retention, bond strength, crack resistance.This paper characterses segregation degree, bleeding rate: anti-crack mortar uses Shandong HPMC, the mixing amount is 1.2 kg/m3 which is 0.33%of cement. According to the test results, mortar to be made is good properties, no crack. The result meets JG158—2004 ETIRS.Cracking in ETIRS is the serious problem in building quality common faults. If surface mortar crack appears in protective layer,it's to be decreased that insulation in ETIRS, water resistance, frost resistance and durability;so it must be studied to strengthen crack resistance and measures. Application results show, anti-crack mortar developed with technological innovation,which crack resistance and crack resistance is better than normal mortar. Anti-crack mortar which can use ETIRS greatly promotes technical performance of traditional mortar and satisfies the anti-crack requests of external insulation building wall.