Problems in the research and application of foam concrete

1 Problems in Theoretical Research
                                                                      Foaming agent is one of the key factors that determines the quality of foam concrete. At present, foaming agents are developing very rapidly. There are many varieties of foaming agents on the market, but the quality is uneven. Our country should strengthen the development of high-quality foaming agents, formulate relevant standards for foaming agents for foam concrete, and standardize the performance testing methods of foaming agents so that the test results between various research units and researchers can be better compared and compared. Reference.

(2) At present, domestic research on foam concrete mainly focuses on strength, density and thermal properties. Research on its dry shrinkage performance, permeability and durability should be strengthened, and various research methods should be established. Theoretical formulas for the correlation between properties and material composition, which will further its application in engineering.

(3) Foam concrete has excellent properties such as thermal insulation, mainly because it has a large number of evenly distributed closed pores inside. However, the current work of domestic researchers rarely involves microscopic pore structure. Research on the correlation between pore structure and performance should be strengthened and corresponding models should be established.
2 Problems in Practical Application
(1) Shortcomings such as low strength, large dry shrinkage and high water absorption are the main reasons that hinder the further development of foam concrete. There is a contradictory relationship between the compressive strength of foam concrete and its density. Ultra-light foam concrete with low density (less than 300kg/m3) has good insulation and sound insulation properties, but its compressive strength is extremely low and the surface is easy to crack, resulting in concrete The water absorption rate increases, thereby affecting the quality of the project; foam concrete with higher strength generally has a higher density, so it has lower thermal insulation and sound insulation properties. Therefore, a balance should be maintained between the strength and density of foam concrete, that is, maximizing strength while reducing density. This can be achieved by optimizing cementitious materials and ultra-light aggregates, and selecting high-quality foaming agents.

(2) Production equipment problems. There is no uniform standard model of mechanical equipment for domestic foam concrete production and construction, and the cement slurry ratio, foam mixing ratio and foam slurry wet density are still adjusted manually, resulting in problems such as inability to accurately measure and difficult to control the slurry density. . Our country should develop automated, large-scale and sophisticated production equipment as soon as possible.

(3) Compared with foreign countries, the overall scale of my country’s foam concrete products is small, the technical level is not high, and there are no leading products for mass applications. Therefore, technological innovation of foam concrete in prefabricated and cast-in-place applications should be strengthened, such as steel structure cast-in-place walls and frame structure foam concrete walls, and its application should be promoted in high-tech fields such as electromagnetic shielding, anti-explosion and sound absorption. . </p