The Performance Optimization Experimental Study On Bond Mortar In Polystyrene Board Insulation System

With the advance of urbanization in China and the increasing requirements of people’s living environment, Exterior insulation technology become more mature, especially Polystyrene board thin plastering exterior insulation system has been developing rapidly, however, there are many defects in the application of the system,the unstable adhesion between thermal insulation layer and the base wall cause a series of quality problems such as empty drum,fall off This is mainly because of low bond strength and poor flexibility. Therefore it is necessary to optimize the performance of the polystyrene board insulation system bonding mortar, preparation of a higher-performance bonding mortar.In this paper, we choose four of high cost performance on the market redispersible powder mixed with binding mortar, use the mixing ratio of low dosage prepare binding mortar, analyzed the influence of the binding mortar’s bond strength and flexibility in the lower redispersible power dosage, through testing the fluidity of mortar mixture and hardened mortar’s28d fold compression ratio,28d tensile bond strength and other performance indicators derived each redispersible powder optimal dosage. At the same time, on the basis of the above test, for binding mortar obtained under each powder’s optimal dosage compared with ordinary mortar bond strength select the best power and dosage. Results show that the performance indicators of Taiwandalian powder in only2.3%lower dosage are better than the other three powders.In polystyrene board system, binding mortar need to have some anti-sag performance and operational time, given cellulose ether’s thickening and retarding effect, so this paper select two kinds of cellulose ether commonly used in the market, which viscosities are100,000and150,000, and make it incorporated into the mortar with the redispersible power, through experiment to study binding mortar’s performance changes. Experimental results show that the binding mortar’s performances are better when the cellulose ether which viscosity is150,000in only2.0%lower dosage mixed with Taiwandalian powder.A large amount of cement in binding mortar and lower redispersible powder dosage lead to lower toughness, this paper studies the influence on the performance of binding mortar after the incorporation of the inorganic admixture part replaced cement. From waste utilization, environmental protection and economic point of view, we take a comprehensive analysis to determine the inorganic admixtures optimal dosage. The test results show that the performance of binding mortar after the replacement of cement with30%fly ash and10%slag. is better.Fine aggregate used in the polystyrene board insulation system binding mortar is usually a single mesh quartz sand, the paper optimized the gradation of mortar aggregate, selected the grated better two mesh quartz sand and made a further test of binding mortar’s performance, The results show that the performance of binding mortar is better when the mass ratio of40-70mesh and70-120mesh is2:3.Because cement hydration needs water to form strength and polymer need dry conditions to form film so that the conservation is inconsistent, the paper made a comparative study on the performance of binding mortar under different curing. The test results show that standard curing7d, then the natural curing21d is the best way to develop the tensile bond strength of binding mortar, both standard curing and first natural curing14d then standard curing14d effect is basically bad, natural curing is the most inappropriate way of curing.By optimizing the mixture ratio to prepare binding mortar specimen and making the specimen under the best curing way to maintenance, compared with traditional ordinary binding mortar to research the performance of optimal binding mortar mixture, the bond properties and the frost resistance of hardened mortar. The results concluded that:compared with the normal binding mortar, optimized binding mortar’s various properties are greatly improved.At the end of the paper, SEM scanning electron microscope is be used to do microscopic analysis and modification mechanism for traditional normal mortar and optimized binding mortar, the results show that optimized binding mortar’s internal cement structure shape, cement hydration products, the bonding of water slurry and aggregate are changed compared with normal mortar, the working performance of optimized binding mortar has been greatly improved.