Research on Low Price Eps Thermal Insulation Mortar with High Performance
|School||South China University of Technology|
|Keywords||EPS insulation mortar Crack resistance High performance Cost|
In view of the increasingly serious energy shortage in China, building energy consumption is growing up, speed up the urgent task of building energy efficiency. EPS insulation mortar insulation effect, the construction is simple and convenient and many other advantages to people of all ages, and is widely used in exterior insulation and finish systems, to meet the 65% energy saving requirements of the national \building energy efficiency one of the mainstream. EPS insulation mortar engineering application and promotion process, there are still some problems, in particular in: (1) easy hollowing, cracking; (2) high thermal conductivity, high cost; (3) EPS insulation mortar main The mechanism of the the organic admixtures cellulose ether and redispersible powder is not yet clear, the existence of errors caused by these two expensive material to use in practical applications. This paper compares the research at home and abroad several representative cellulose ether, redispersible latex powder products of EPS insulation mortar consistency, security water-based, strength and performance, and SEM observation, assay methods cellulose ether redispersible polymer powders mechanism. The results showed that the same dosage under domestic cellulose ether than imports of cellulose ether thickening poor water retention effect, domestic redispersible powder and imported redispersible powder compared sticky (less than 1%) in the low-dosage The knot strength is equivalent, but the dosage is more than 1%, but reduces the adhesive strength of mortar. The cellulose ether has a certain air entraining effect, introduction of the bubble diameter between 0.3 ~ 0.7mm; cellulose ether can effectively improve the water retention rate of the mortar, so that the natural curing conditions cement hydration sufficiently cellulose ether dosage Etsu high, the higher the degree of hydration of cement; mechanism of cellulose ethers is: the adsorption of large amounts of water dissolved in water to form a continuous film structure, with the conduct of the cement hydration, the film structure is gradually thinned release moisture, and the formation of large holes , retains water film role at the same time exist simultaneously. Redispersible latex powder dispersed film forming around the cement particles, the higher the dosage, the thicker the film structure, to the mortar hardening 12h after the redispersible powder film is not completely hardened film-forming; the polymer powders film early water resistance poor; bentonite can absorb some of the latex powder to thinning of the membrane structure; redispersible latex powder mixing does not change the type of hydration products, but can reduce the orientation and enrichment of calcium hydroxide, as redispersible powder doped increase in the amount of mortar hydration products increasingly dense structure. By adjust EPS ash particles, mineral admixture material type and reasonable mixed guarantee the EPS insulation under the premise of the mortar strength, reduce the thermal conductivity, its requirements to meet the national standard of 0.06 W / (m · K) EPS insulation mortar; mixed with the right amount of water repellent can reduce saturated water absorption, increase its compressive strength and tensile bond strength softening coefficient to improve the bonding between the EPS particles and slurry, thereby enhancing the EPS insulation mortar anti-empty shedding drum capacity; cracking test results show that the water retention larger EPS insulation mortar early cracking, drying shrinkage values, adjust the water rate in more than 85%, EPS insulation with good crack resistance can be obtained mortar, and has good weather resistance. EPS insulation mortar developed the performance to meet the national standard GB / T 20473-2006 \The mortar the problems is a high-performance EPS insulation mortar. Lignocellulose, modified bentonite and modified poly (ethylene oxide) crumb performance of EPS insulation mortar water retention, strength. The lignocellulose with 0.3% (percentage of cementitious material quality), 4% modified bentonite, 0.5% poly (ethylene oxide) polymer powders instead of 0.2% cellulose ether and 1% redispersible powder, EPS insulation mortar performance meet the standard type I requirements, the cost of production compared to the commonly used formula on the market per ton reduced by about 4.7% per square costs about 450 yuan, while the the type Ⅰ EPS insulation mortar market price of 800-1200 yuan / square, with a larger space and good prospects. Select wood cellulose, modified bentonite and lime as water thickening material, orthogonal experiment to study its impact on the performance of surface mortar, as well as cracking test, and compared with the common market on the surface mortar. The results showed that the optimum ratio of the lignocellulose 0.4% modified bentonite 4% and lime 15%, the mortar prepared according to the ratio of resistance to cracking good; compared to commonly used surface mortar properties on the market, water retention, strength performance such obvious advantages; relatively low cost of the mortar, the only commercially available with 78% of the costs of the kinds of mortar, and has broad market prospects.