Application of Alkali Resistant Glass Fiber Mesh Cloth in External Wall Thermal Insulation System
According to relevant literature reports, the area of houses built in my country every year is as high as 1.6-2 billion square meters, almost exceeding the sum of the annual construction areas of all developed countries. Among these new buildings, only 10-15 can meet the national energy-saving standards, and more than 80 are high-energy-consuming buildings, and the energy consumption per unit building area is 2-3 times that of developed countries. Therefore, my country's building energy conservation is imminent. In July 1996, the "Civil Building Energy Conservation Standard (Heating Residential Buildings)" was promulgated and implemented. The "Standard" takes my country's residential energy consumption in the 1980s as the benchmark, and requires new residential buildings to save 50% of heating energy consumption, of which 30% is achieved by improving the thermal insulation performance of the building envelope. In the building envelope, walls account for the largest proportion of heating energy consumption, accounting for about 32.1 to 36.2 of the total energy consumption. Therefore, how to improve the thermal insulation performance of the wall becomes the top priority. It is on the basis of this understanding that people realize that it is necessary to comprehensively develop and promote new high-efficiency wall insulation systems and insulation materials.
External wall insulation technology
At present, the external wall insulation of energy-saving houses in my country is divided into four types of thermal insulation: internal thermal insulation, sandwich thermal insulation, external thermal insulation and comprehensive thermal insulation. External thermal insulation of external walls is the main thermal insulation form advocated and promoted by the Ministry of Construction. Well, it is the most widely used building insulation technology in our country. This building thermal insulation technology is to place the thermal insulation system on the outside of the outer wall, so that the temperature difference effect of the main structure is greatly reduced, the temperature deformation is reduced, the structural wall is protected and the cold (heat) can be effectively blocked. ) bridge, which is beneficial to prolong the life of the structure. Today, external wall insulation systems (eifs or etics) have been applied to building exterior walls all over the world, which not only achieves the energy saving effect of saving 30-70% of the energy consumption of heating and cooling systems, but also provides a healthier and more comfortable environment for human beings. Living Environment. Therefore, in the wall insulation method, the external wall insulation technology has been widely used.
1. my country's existing external wall insulation system
The Ministry of Construction's "External Wall External Thermal Insulation Engineering Technical Regulations" recommends five external thermal insulation systems for external walls: EPS board thin plaster external thermal insulation system; rubber powder EPS particle thermal insulation slurry external thermal insulation system; EPS board cast-in-place concrete external thermal insulation system ( Including net and no net two); mechanical anchoring eps steel wire mesh frame board external insulation system. Other external wall insulation systems under development include xps board external insulation system, polyurethane rigid foam external insulation system, insulation block and prefabricated insulation board external insulation system and rock wool external insulation system, etc.
In recent years, among many technical systems of external wall thermal insulation, EPS board thin plaster external thermal insulation system is the most popular in the market. Not only in China, but also in developed countries and regions such as Europe and the United States, the EPS board thin plaster external insulation system is also the preferred system. The basic structure of the thin plaster external thermal insulation system is briefly introduced.
2. Construction of EPS board thin plaster external insulation system
(1) Basic wall
The outer wall of a building that acts as a load-bearing or enclosure. Exterior walls must be strong and dry, and mold must be removed before installing external insulation.
(2) Adhesive
Composed of a certain proportion of bonding mortar and polymer, it is used to bond the insulation material to the base wall. Therefore, it is required to have good bonding properties for both exterior walls and insulation materials.
(3) Form of adhesive
At present, two types of adhesives, one-component type and two-component type, are widely used in construction: the one-component type is a dry powder adhesive that is pre-mixed during production, and a certain proportion of water is added and stirred according to the instructions on the construction site. That is, its construction and operation are convenient, the material performance is stable, and it is an environmentally friendly material; the two-component type refers to the production of liquid adhesive (component a) and special powder (cement, quartz sand, additives, component b). The construction site can be put into use after mixing evenly according to the instructions for use. Its bonding strength is higher than that of a single component, but the storage, transportation and construction operations are more cumbersome, and human errors are prone to occur during use, which is not environmentally friendly.
(4) The key component of the adhesive - polymer
At present, the adhesive polymers used in the external insulation system of polystyrene insulation boards in China include pure acrylic emulsion, styrene-acrylic emulsion, vinegar-acrylic emulsion and vinyl acetate-ethylene copolymer emulsion (vae emulsion, called eva abroad), etc. Abroad mainly for acrylic and vinyl acetate copolymer emulsion. From the emulsion type products that enter the Chinese market, there are products from the United States, the products of a South Korean company, etc., all of which are made of acrylic; while the dry powder products that enter the Chinese market, whether they are products from the United States, Germany, France, Japan, or South Korea Vinyl acetate copolymer emulsion dry powder is mostly used. Compared with acrylic products, vinyl acetate copolymer emulsion dry powder products have better overall performance, mainly in:
①High initial viscosity. It is beneficial to the positioning of the polystyrene board and preventing the glass fiber mesh from warping during construction.
②Comprehensive bonding performance is good. In the external thermal insulation system, the wall matrix and the alkali-resistant mesh are polar materials, and the polystyrene board is a non-polar material. Acrylic acid polymer is polar, so it has better bonding performance with wall substrate and alkali-resistant mesh cloth and lower bonding performance with polystyrene board; in vinyl acetate copolymer emulsion, its structure has both Polar groups, there are also polar groups, so that better comprehensive bonding performance can be obtained.
(5) Eps board
Eps board as insulation material.
