Talking about building thermal insulation material and its application

Shanxi Building talks about building thermal insulation materials and their application Cui Yuliang (Taiyuan University of Technology, Taiyuan 030000, Shanxi, China), the application of the top and basement, pointed out that the application of thermal insulation materials has improved energy efficiency, so the application of thermal insulation materials in construction should be vigorously promoted. .

1 Overview At present, China is developing rapidly with 1 billion m2 of civil buildings per year, and building energy consumption has grown from 11% in the 1970s to 28% today. Therefore, it is imperative to develop energy-efficient buildings, which not only saves energy. To reduce pollution, but also to improve people's comfort and improve the living and working environment. According to incomplete statistics, if the building uses good thermal insulation materials, it can reduce energy consumption by about 25%~51%. Reasonable use of thermal insulation materials can improve the performance of buildings, especially in air conditioning, heating, refrigeration, and freezing. In buildings, it can greatly reduce heat loss and save energy.

The energy loss of building dwellings in China is roughly 50% of the wall, 10% of the roof, 25% of the doors and windows, and 15% of the basement and the ground. The thermal insulation project for building envelopes is used in buildings. The heat loss of the outer guard is large, and the wall accounts for a large proportion.

Therefore, wall energy saving is a key link in building energy-saving development. The development of external wall insulation technology is the main direction and main way of building energy conservation.

2 Classification and characteristics of building thermal insulation materials Insulation materials are usually materials with a thermal coefficient of not more than 0.2. And a wide variety of thermal insulation materials, mainly for organic thermal insulation materials (such as various resins, cork, wood, wood fiber and their products); inorganic thermal insulation materials (such as glass wool and its products, mineral wool and mining Cotton products, microporous calcium silicate, expanded vermiculite and products, aerated or foam concrete, pumice concrete and its products, etc.; metal insulation materials (such as aluminum, aluminum foil, aluminum foil composite light board, etc.). Insulation insulation materials must meet the application requirements and basic requirements of GB/T17369~2006 building insulation materials in the architectural design, use type and construction method. In addition to considering the thermal conductivity of the material, the selection process should also pay attention to the corrosion resistance, flame retardancy, hygroscopicity and strength of the material. Insulation materials with different performance and different characteristics must meet the corresponding specifications.

Exterior walls, doors and windows, roofs and floors are the main parts of building energy loss.

Therefore, thermal insulation technology mainly takes measures from these aspects. It is necessary not only to develop environmentally-friendly and efficient insulation materials, but also to increase the sealing performance of the envelope structure to achieve the desired insulation effect.

1) External wall insulation materials mainly include: rubber powder polystyrene particle exterior wall insulation material, which is characterized by small thermal conductivity, good corrosion resistance, good frost resistance, high compressive tensile strength, strong adhesion, and thermal expansion rate. Small, moisture-proof and waterproof, not hollow, broken, can be used both on the inner wall and the outer wall, the construction is simple, and the thermal insulation performance is stable. Expanded vitrified microbeads external wall insulation materials and inorganic thermal insulation mortars are new types of thermal insulation mortar materials used for painting interior and exterior walls in recent years. They have waste utilization, energy saving and environmental protection, and excellent performance. Excellent in fire and moisture resistance, long service life, and wide range of raw materials, convenient processing and low price. XPS polystyrene extruded board exterior wall insulation material (hereinafter referred to as extruded board), this material is used as the outer wall insulation insulation of the building, XPS extruded polystyrene board thin plastering external wall insulation effect compares EPS effect, has more strength High, and better thermal insulation performance, more airtight and so on. EPS expansion material board (referred to as benzene board), the material has small thermal conductivity and high strength; it has strong acid and alkali corrosion resistance and good heat resistance. Has good waterproof and wind resistance. It can also handle cracks in the exterior wall and water seepage and water leakage. 2) Roof insulation materials mainly include: In low temperature areas or buildings equipped with air conditioning and cooling equipment, the roof of the building is usually designed with an insulated roof. In order to increase the insulation effect of the roof, it is necessary to add a thermal insulation layer to the roof. It is usually a thermal insulation material with good water repellency, poor water absorption, poor thermal conductivity and high tensile strength and compressive strength. Roof insulation insulation materials are usually divided into three types: porous thermal materials (common mineral wool and mineral wool products, asbestos and its products, glass wool and its products, etc.); granular insulation materials (commonly used There are expanded perlite and products, expanded vermiculite and products added with appropriate amount of cementitious materials to mix); porous insulation materials. The overhead ventilation layer is usually made of bricks, tiles, concrete and other materials and products. 3) Door and window insulation materials mainly include: doors and windows in the building mainly play the role of lighting, ventilation and enclosure, while enhancing the aesthetics of the building, is also the main part of heat exchange and energy loss. With the development of modern building technology, in order to improve the aesthetics of the building and improve the comfort of work and life, the door and window area of ​​the building has greatly increased, especially the all-glass curtain wall building. This determines that the energy saving of the envelope structure must adopt a better method and higher requirements. At present, the method for energy saving of the door and window is to improve the sealing performance and improve the thermal insulation performance of the material. In recent years, new door and window materials have emerged.

Among them, UPVC plastic profiles are the most common, and they have wide raw materials, low production energy consumption, less pollution, stable quality, good thermal insulation performance and good sealing performance.

3 The application of thermal insulation materials in construction increases the cost of building envelopes to only 3% to 5% of the total investment cost, while the energy saving effect can reach 20%~40%. The quality of thermal insulation materials and construction quality It is an important factor affecting building energy efficiency.

1) Application of insulation materials in the wall. It is no longer necessary to increase the thickness of the wall by means of a single material to increase the thickness and achieve the purpose of heat preservation. In order to adapt to environmental protection, comfort and energy saving, composite walls have become the mainstream of modern buildings. Composite walls are usually made of reinforced concrete or other block materials for load-bearing components, together with thermal insulation materials, in frame structures or shears. The wall is made of thin-walled material for thermal insulation. Among the wall insulation materials, the most commonly used rubber powder polystyrene pulp. It is formed by solidifying the polystyrene particle aggregate with water, and rubbing it on the outer surface of the wall to form a dense insulating layer. Most of the polyphenylene granule aggregates are formed by recycling waste polystyrene board and rough processing. Incorporating fly ash into the production process not only reduces costs, but also realizes waste utilization. The wall insulation is comprehensively considered from the inside, the insulation layer, the sandwich insulation layer and the external insulation layer to achieve the desired effect to the utmost extent. In this respect, there are also differences in various countries around the world. In China, the sandwich insulation method is more common, and most of the methods used in Europe and America use foamed benzene board. For example, German exterior insulation buildings account for 80% of the total, and 70% of them use foam polystyrene board. 2) Insulation materials are applied on the top of the building. The roof is an important part of the energy loss of the building. Firstly, it must be waterproofed, and the effect of curing in the thermal insulation material under the roof waterproof layer on the durability of high performance concrete Wang Zhiming (Lüliang Highway Construction Co., Ltd., Luliang 033000, Shanxi) The effect of internal curing on the durability of high performance concrete yields some instructive conclusions.

Table 1 Concrete mix ratio test piece No. Cement consumption kg/m3 Water consumption ratio Curing water kg/m3 Light aggregate kg/m3 Slump cm Fine aggregate kg/m3 Coarse aggregate In recent years, high performance concrete due to its superior machinery And durability 1 has received much attention. High performance concrete can significantly reduce maintenance costs and increase service life. Compared with ordinary concrete, high-performance concrete can adapt to various harsh environments. It has been widely used in marine engineering construction, high-rise buildings, bridge decks and piers, thin-walled shells, and airport pavements. However, high performance concrete is prone to cracking at an early age. In order to reduce the self-shrinkage and cracking of high-performance concrete, many researchers have introduced high-performance mixed pre-saturated lightweight aggregates. Saturated lightweight aggregates can provide internal curing water to counteract self-drying 4, so this method is known as internal curing.

The amount, type, particle size and saturation of the curing medium have a considerable influence on the internal solidification of high performance concrete. M. In addition, the effectiveness of curing depends on the permeability of the cement slurry, ie the water to cement ratio. It can be seen that the water-cement ratio is the main factor affecting the durability of concrete. In the current research of high performance concrete, the main research is its adsorption capacity, gas permeability, resistance to chloride ion penetration, strength, dynamic elastic modulus and shrinkage.

1 Sample preparation and test methods 1.1 Raw material cement: Conch brand P.042.5 ordinary Portland cement. Aggregate: coarse aggregate ~4.5mm and 4.5mm~8.5mm gravel, water absorption rate is controlled at 1.5wt.%. Fine aggregate adopts ordinary medium sand, water absorption rate is controlled at 0.5wt.%. Light aggregate adopts 2.0 Mm ~4.0mm Yichang shale round spherical ceramsite.

Materials, such as expanded perlite, glass wool, etc.; the insulation of the sloping roof is arranged between the tile and the purlin or above the ceiling. Flat roofs are usually placed under the waterproof layer and above the structural layer due to the gentle slope of the roof. Ventilation and heat insulation is usually to set up an overhead ventilation layer on the top of the building to block the sun exposure, and use hot pressing and wind pressure to exchange the space with the outside world by hot air, which can solve the circulation of air and play ―The fixed insulation effect. There are usually two ways to set up the ventilation floor: one is to make an overhead ventilation and insulation layer on the roof, and the other is to use the space inside the ceiling to make the ventilation floor. In addition, you can lay mineral wool felts and mats on the ceiling, or directly lay loose insulation cotton in this space, or directly hang the insulation made of glass wool or rock wool insulation materials or decorative veneers. ceiling. 3) Application of insulation materials in the basement. Modern buildings have basements or underground spaces, and the floor of the living space is not directly exposed to the outside environment, which provides favorable conditions for the insulation of living spaces. Most of the basement or underground space is not a heating zone, admixture: naphthalene-based high-efficiency water reducer powder.

1.2 Mixing ratio design In order to systematically study the effect of internal curing on the durability of high performance concrete, the cured samples and ordinary samples with different water-cement ratios were designed. The specific configuration is shown in Table 1.

1.3 Experimental methods 1) Transport performance. The adsorption performance was tested in accordance with the ASTM C1586-05 standard, and the sample was made into a cylinder having a diameter of 200 mm and a height of 80 mm. The gas permeability was measured using the same sample, first cured under (30 2)T: sealed conditions, and then exposed to 70T at 1d, d and 28d ages to dry to constant weight for testing. The measured sample was subjected to a water bath, sealed on the side and the top, and the bottom was submerged under water 3 mm to 5 mm. The chloride ion permeability of the concrete was tested according to ASTM C1202~97.

In the winter, there is still a certain amount of heat lost through the underlying floor. Therefore, under the subfloor of the building, high-performance insulation materials must be filled.

4 Conclusion Insulation insulation of buildings is the key link in China's future construction projects. At the same time, the quality of thermal insulation materials and products is a key factor affecting building energy conservation, and it is also a new topic in the development of building materials, which has been valued by countries all over the world. The building's thermal insulation material not only improves the comfort of living, but also improves the energy utilization rate, which is of great significance for mitigating energy pressure.

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