The effect of rubber powder on the performance of flexible thermal insulation mortar Zhang Zhijun, Cao Luchun (Xuzhou Institute of Technology, Xuzhou 221008, Jiangsu, China) Performance research and testing proves that the use of a rubber powder can reduce the strength of mortar and improve the folding pressure ratio of mortar and make the insulation The ability of the mortar to resist deformation increases and the crack resistance of the thermal insulation mortar is improved.
The traditional mortar insulation material exposed many defects during use, such as wall hollowing, cracking, falling off, etc., which caused the wall leakage, ventilation, peeling, seriously affecting the quality of the project and the normal use of the building. It also restricts the popularization and application of insulation mortar. Therefore, how to solve the cracking problem of the system has become the focus of common concern in the industry. With the implementation of energy-saving and emission-reduction work in China, the use of external thermal insulation systems in buildings is becoming more and more common, and higher requirements are placed on the performance of thermal insulation mortars, especially crack resistance. In view of this, it is necessary to develop a high performance flexible thermal insulation mortar.
The flexible thermal insulation mortar we studied abandoned the traditional "rigid crack resistance technology route" in thermal insulation structure design, and adopted the "climbing layer-by-layer gradient, flexible release stress" crack resistance technology route. Practice has proved that the establishment of this kind of flexible anti-crack system can effectively absorb and absorb the thermal stress deformation 121, thus solving the technical problem that the domestic and foreign thermal insulation mortars are prone to harmful cracks. It is currently a good anti-cracking effect. External wall insulation material.
According to research, rubber powder can replace part of the fine aggregate in the mortar to enhance the flexibility of the mortar. In the mortar strength test, the insulation mortar sample with rubber powder shows a ductile failure mode, unlike the ordinary mortar. Sudden rupture indicates that the flexible mortar specimen can tolerate large failure weights and large deformations. 131. This paper mainly studied the effect of rubber powder on the physical and mechanical properties of mortar.
1 Preparation and Testing of Flexible Thermal Insulation Mortar 1.1 Raw material 32.5R ordinary Portland cement, produced by Zhonglian Julong Huaihai Cement Co., Ltd.; fly ash, produced by Xuzhou Huarun Power Co., Ltd.; expanded perlite, produced by a company in Xinyang, Henan; EPS Granules, using a special crusher processing, particle size less than 5mm, a good gradation; polymer powder, polypropylene fiber (diameter 201 * length 18mm), admixtures are commercially available.
1.2 Preparation EPS particles are first wetted with a surfactant and a coupling agent, and then an appropriate amount of cement is added and stirred to coat the surface of the particles with a layer of cement paste, and then cement, fly ash, expanded perlite, polymers and fibers are added. The raw materials are mixed uniformly according to the mixing ratio shown in Table 1, and the consistency of the control mortar is about 8cm. After the test piece is formed, it is cured in the curing box for 28 days, and the performance is tested. 14.1.3 Testing the performance of the thermal insulation mortar Refer to JCJ70-90. The test method for performance was carried out. The compressive strength and flexural strength test were performed using a triple trial of 40 mm×40 mm×160 mm, and the molded rice of the test specimen was subjected to mechanical vibration.
The flexural strength adopts the flexural testing machine, and the compressive strength test adopts the YAW-2000D microcomputer-controlled electro-hydraulic servo pressure testing machine.
Fund Project: Jiangsu Provincial Natural Science Research Project Grant Project (06KJD560176) Table 1 Ratio of Thermal Insulation Mortar Cement Fly Expanded Perlite Polypropylene Fiber EPS Particles Polymer Powder Water-retaining Agent Expansion Agent 2 Test Results and Analysis 2.1 Effect of Rubber Powder Content on Mortar Water-cement Ratio Rubber powder was added to the mortar. In order to meet the construction requirements, the water-cement ratio was controlled by controlling the fluidity of the mortar. In the test, the mixture has good cohesion during the stirring process, but it tends to form a mass and makes the mortar not easy to flow. Therefore, in order to maintain the fluidity of the mortar, the following table 4 shows the influence of the fineness of the rubber powder on the water-cement ratio and fluidity of the mortar. No. The ratio of the rubber powder powder to the water/cement ratio of the stock/mm is shown in the table above, and the sinking degree of about 70 mm is maintained. There is no obvious difference in the water-cement ratio of the 80 mesh and the 100-mesh rubber powder. Into the 200-point rubber powder, to maintain the same submersion, water demand increased, the water-cement ratio increased by 5%, indicating that the finer the rubber powder, the greater the amount of water required.
Table 5 Strength of mortar mixed with different fineness rubber powder No. 28d Flexural strength/Mpa 28d Compressive strength/Mpa folding pressure ratio It can be seen from Table 5 that a mortar with a fineness of 200 mesh of rubber powder is resistant for 28 days. The flexural strength and compressive strength are the highest, and the flexing ratio is also the highest. Therefore, it can be seen that the fineness of the 200-mesh rubber powder is advantageous for the performance of the mortar.
3 Conclusions Through the test of mortar performance, the following conclusions can be drawn: Under the condition that the fluidity of the mortar remains unchanged, the water-cement ratio increases with the increase of the amount of rubber powder; the compressive strength of the mortar increases with the amount of rubber powder The decrease of the increase; () The flexural strength of the mortar decreases with the increase of the rubber powder content; (4) With the increase of the rubber powder content, the folding pressure ratio of the mortar first decreases and then rises; () Rubber powder The finer, the greater the amount of water required for the mortar, the more favorable it is to the strength and folding ratio of the mortar.
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