New lightweight wall will become the mainstream of the building

A senior Chinese leader pointed out at the Copenhagen World Climate Change Conference that by 2020 China will achieve a quantitative reduction of carbon dioxide emissions per unit of GDP by 40% to 50% from 2005. According to the forecast of authoritative organizations, if this goal is achieved, the state will pay up to 300-500 billion yuan in economic costs, and the corresponding social cost investment is even more difficult to estimate. This shows that the Chinese government is saving energy and reducing emissions. determination. In energy-saving and emission-reduction, building energy-saving has always been a key point, and in building energy-saving, the research and development of wall technology is extremely important. In fact, the construction department has been working hard to promote the related work of wall material reform and has achieved certain results.

Recently, the Ministry of Housing and Urban-Rural Development pointed out in the “Circular on the Supervision and Inspection of Building Energy Conservation in the National Construction of Residential and Urban-Rural Areas in 2010” that at present, China’s wall material innovation work has achieved positive results. According to incomplete statistics, in 2010, the country’s output of new wall materials exceeded 400 billion standard bricks, accounting for about 60% of the total output of wall materials, and the application of new wall materials reached 350 billion standard bricks, accounting for a total of wall materials. About 70% of the application volume has fully completed the development goals of the wall materials innovation determined by the State Council. In recent years, under the background of building energy-saving and emission-reduction, the Ministry of Housing and Urban-Rural Development has paid more and more attention to the renovation of wall materials. With the increase of state support, the effectiveness of wall materials innovation has gradually become apparent.

According to the deputy director of the Steel Structure Design Committee of the Zhejiang Steel Structure Industry Association, most of the load-bearing walls in traditional buildings are mainly made of single materials. Such walls are often difficult to meet high insulation and heat insulation requirements. Therefore, Need to do another insulation layer to form a composite wall. The composite wall is generally made of brick or reinforced concrete as the bearing wall and compounded with the insulation and heat insulation materials. The composite wall mainly includes the exterior thermal insulation composite wall and the inner thermal insulation composite wall. In many years of engineering practice, due to materials, construction, construction and other reasons, the internal thermal insulation composite wall also exposed some defects, such as many internal thermal insulation composite wall decorative layer caused by thermal expansion and shrinkage easily lead to cracking; occupied indoor The use of space, households have low room rate; due to ring beams, floors, structural columns, etc. will form a thermal bridge, heat loss, thermal insulation effect is not good, so the inner thermal insulation composite wall is gradually replaced by the outer thermal insulation composite wall.

In the exterior thermal insulation composite wall, the currently used thermal insulation materials mainly include organic materials such as polystyrene foam panels and rigid polyurethane foam panels, which are fixed to the outer surface of the outer wall in the form of external stickers to achieve the effect of thermal insulation. Compared with the inner thermal insulation composite wall, it has the advantages of protecting the main structure, prolonging the service life, eliminating the influence of the thermal bridge, improving the wet condition of the wall, and keeping the indoor temperature constant. However, after years of engineering applications and tests, some of its problems have gradually become exposed. Problems such as cracking have caused concern in the industry, especially after the “11·15” fire in Shanghai. These problems have once again become a hot topic. In this context, it is urgent to develop and promote a new type of wall with good energy-saving effect. At the same time, all other performance indicators that meet the national standards are imminent.

It is understood that from the 1980s onwards, the former Ministry of Construction began to work on building energy-saving work, and has successively issued a series of documents related to building energy-saving design standards. In 1986, civil building design standards applicable in northern regions were promulgated, requiring energy conservation to reach 30%; in 1996, 50% of energy conservation standards were introduced; in 2000, the “Regulations on Energy Efficiency of Civil Buildings” promulgated by the Ministry of Construction was also implemented. In November 2006, the former Ministry of Construction issued a notice requesting that by 2010, 50% of new buildings in urban areas in China will be energy-efficient. The promulgation of this series of documents shows the importance and urgency of building energy conservation. The thermal performance of the enclosure structure plays an important role in building energy conservation. This requires that the wall material used in the building envelope must have good thermal performance. The thermal performance of the wall includes both thermal insulation and thermal insulation. Due to the vastness of China's territory and the large differences in climate between regions, severe cold regions and cold regions need to meet the winter insulation requirements; summer and winter warm regions need to meet the summer heat protection requirements; while hot summer and cold winter regions meet the summer heat protection requirements, Also take into account the winter insulation.