The Study And Application Of Hydrophobic Energy-saving Material In Building

With the aim to resolve the most of thermal insulation materials absorbing water and humidity,sequentially thermal conductivity augmented,and water interacted with materials as mortars,plasters,etc,so causing their deterioration (detectable through exfoliation, scaling,crumbling,etc),a hydrophobic building thermal insulation material was studied in this paper.The effect of two adhesives(EVA and PVA) addition on flexural strength and compressive strength,the influence of water- repellent agent addition on water absorption, the relationship between the dry density and the thermal conductivity and between the thermal conductivity and water absorption were investigated,the conclusion was obtained that optimum addition of adhesive PVA was 4.5%,the optimal addition of water- repellent agent was 300g and the density of EPS thermal insulation mortar shuld be controlled below 250 Kg/m3.The optimal compositioin of hydrophobic EPS thermal insulation mortar was:cement 300g,EPS30g,water- repellent agent300g, PVA14g,water360g, polypropylene fibers 2g.The performance measurement of the insulation product were:the wet density was 394 Kg/m3;The dry density was 244 Kg/m3;the compressive strength was 460 KPa;the thermal conductivity was 0.058 W/(m·k);the heat accumulating coefficient was 1.5 W/(m2·k);The line contraction rate was 0.3%;the softening coefficient was 0.6.With the aim to the utilization of coal fly ash,hydrophobic modification of coal fly ash was studied.Coal fly ash was modified by carboxylic acid surface treatment agent.The microstructure and the chang of properties of the modified coal fiy ash and unmodified coal fiy ash were investigated by means of TEM,IR,contect angle,et al.Contact angle results showed that surface energy of coal fly ash was reduced and wettability was reversed;TEM photographs revealed that modifying agent adsorption layer was formed on the surface of coal fly ash;it was concluded by IR that the surface treatment agent was attached to coal fly ash by chemical bond and the main adsorption mode was chemical adsorption but was not physical adsorption.In addition,the optimum insulation thickness of the thermal insulation material and the construction technology of the outer wall heat preservation was introduced in the paper, and its good enegy-saving effect has been comfirmed in the engineering application yet.