Problems existing in foam concrete in my country

Theoretical research

(1) Foam concrete has excellent properties such as light weight and thermal insulation, mainly because Foam concrete does not contain coarse aggregates and has a large number of closed cavities inside. Most scholars at home and abroad have done a lot of research on the macroscopic aspect of concrete, but there is a lack of research on the microstructure of foam concrete. There is a systematic lack of research on the correlation between the excellent properties, constituent materials and microstructure of foam concrete.

(2) In recent years, there has been relatively in-depth research on the density, strength and thermal properties of foam concrete in China. However, in terms of durability, permeability, dryness and There is still a lack of research in areas such as shrinkage performance.

(3) The current density of foam concrete in my country ranges from 400 to 1600kg/m3, which is still far behind the density of polystyrene foam boards. . The density of ultra-light foam concrete is generally less than 100kg/m3, and its thermal conductivity is roughly close to that of inorganic insulation boards, about 0.04. Foam concrete of about 100kg/m3 can be produced in the laboratory, but how to produce it stably in industry and how to break the density to about 70kg/m3 are two issues that scholars will strive for in the next stage.

(4) Domestic authoritative departments lack various implementation standards and testing methods for foam concrete. Different development units use their own tests based on their own research status. Methods and technical indicators.

Practical application

(1) Production equipment problems. Up to now, domestic machinery and equipment for the production of foam concrete and foam concrete construction lack consistent models, and the foam mixing ratio, foam slurry wet density and cement slurry ratio need to be prepared by manual experience, which cannot be determined. Achieve precise control of slurry density and measurement.

(2) Defects such as high water absorption, large drying shrinkage, and low compressive and flexural strength are common problems with current foam concrete. When the bulk density of foam concrete is about 830 kg/m3, its compressive strength is mostly below 2.0MPa. The compressive strength is too low to be used in engineering applications. When the apparent density of foam concrete is not greater than 400kg/m3, its compressive strength as a thermal insulation material is below 0.4MPa.

(3) Application issues in high-tech fields. In my country's high-tech field, the application fields of foam concrete are relatively limited, such as electromagnetic shielding, nuclear facility engineering, offshore engineering, explosion resistance, etc. Research on the microstructure and properties of foam concrete is a top priority, and its research efforts should be strengthened to tap its potential and develop high-performance foam concrete products [34].

(4) In recent years, great achievements have been made in the application of foam concrete in China. However, compared with foreign countries, the overall scale of foam concrete products is small, the technical level is low, and there are no leading products that are widely used.

At present, with the development and growth of our country's economy, the country is paying more and more attention to aspects such as ecology and energy conservation. Foam concrete has been widely used in building materials in recent years because of its various excellent properties. It has replaced organic insulation materials in thermal insulation materials and has broad application prospects. Although there are still certain problems in theoretical research and practical application, as long as we continue to strengthen in-depth research on the theory of foam concrete, optimize and upgrade its production equipment, production technology, etc., and combine the functional advantages of foam concrete with construction With the domestic development situation of energy conservation, foam concrete will definitely become the most important "green" functional material for construction in our country. </p