Aerated concrete in China is the earliest developed and most productive type of new wall materials. After nearly 50 years of development, it has formed a complete industrial system of material production, equipment manufacturing, supporting material supply, design and scientific research. According to incomplete statistics, the output of aerated concrete in China is close to 70 million cubic meters, ranking first in the world.
In the process of wall material innovation, Aerated concrete block It has become the main force to replace small pieces of clay bricks. 98% of the aerated concrete in the country is massive, which is used to build internal and external walls. Its bulk density is 500~800kg/m3, which is equivalent to 1/3~1/5 of ordinary sandstone concrete and 1/2.5~1/3.5 of clay solid brick. Of course, its compressive strength cannot be high, only 2.5~10MPa. It can be used as a non load-bearing infill wall, or it can be used as a load-bearing wall after special structural treatment, or even used as a load-bearing wall with rustproof reinforcement.
However, the vast majority of domestic aerated concrete products are blocks, which are moved up and down manually and then built manually on site, which can not guarantee the quality of the wall, but also increase the labor cost. In foreign countries, the ratio of aerated concrete blocks to slabs is almost 6:4. Aerated concrete slabs are commonly used in high-rise buildings, not only for internal and external walls, but also for reinforced aerated concrete slabs for floors and roof slabs. The author has cooperated with Shenzhen Architectural Design and Research Institute to analyze different types of residential buildings. In addition to the reinforced concrete frame system, the total volume of internal and external wall panels and floor slabs accounts for 46%~59% of the volume of structural components. In other words, if we learn from foreign experience and change the internal and external wall panels and floor slabs into aerated concrete slabs, the structural dead weight of the whole building will be reduced by about 1/4, and the resources saved will be huge. We should also consider the savings of steel reinforced concrete load-bearing structures due to the use of aerated concrete internal and external wall panels and floor slabs.
The degree of standardization of aerated concrete slabs is very high, and its specifications and dimensions are completely available for production in aerated block factories at present. However, the weight of single component plus lifting appliance is less than 1t, which is quite different from the current situation that ordinary concrete entire exterior wall panels and floor slabs are often 5t and even have to be installed with 10t cranes.
Aerated concrete slats of different specifications are cut from large green bodies, and there is no problem of manufacturing, depreciation and scrap of reinforced concrete component molds, which is also a contribution to energy conservation and emission reduction. Strictly speaking, only by changing the internal and external wall panels and floor slabs to use standardized components, rather than concrete components "tailored" for specific projects, can we truly achieve standardization, finalization and industrialization, which is the biggest advantage of aerated concrete panels.
