As the average particle size of Ewende micro silica powder (silica fume) is 0.1um, which is only a few hundredths of the average particle size of cement, the physical properties of micro silica powder (silica fume): the tiny particles of micro silica powder (silica fume) have a high degree of dispersion, which can be sufficiently filled between the cement particles to improve the denseness of the slurry after it hardens, thus improving the strength and service life of the concrete.
Aerated concrete is a new type of building material that is lightweight and porous, heat preservation and insulation, good fireproofing performance, can be nailed, sawed, planed and has a certain seismic capacity. As early as in the early thirties, China began to produce this product, and widely used in Shanghai International Hotel, Shanghai Tower, Fuzhou Building, People’s Bank of China Building and other high and low-rise buildings. It is an excellent new building material. And it has the advantages of environmental protection and so on. Thus aerated concrete adding a certain amount of micro silica powder (silica fume) has the following characteristics:
1. Light weight
Aerated concrete block generally weighs 500-700 kg/m3, which is only equivalent to 1/4-1/3 of clay and gray sand bricks, and 1/5 of ordinary concrete, which is one of the lighter ones in concrete, and is suitable for the filler wall of high-rise buildings and the load-bearing wall of low-rise buildings. The use of this material can make the self-weight of the whole building is more than 40% lower than the self-weight of ordinary brick-concrete buildings. As the self-weight of the building is reduced, the earthquake destructive force is small, so it greatly improves the seismic capacity of the building.
2. Good thermal insulation performance
The thermal conductivity of gray sand aerated concrete is generally 0.11-0.18 kcal/m? Hour? Degree, only clay bricks and gray sand bricks 1/4-1/5, (the thermal conductivity of granular clay bricks is 0.4-0.58 kcal/m? Hour? degree; gray sand brick thermal conductivity of 0.528 kcal/m? Hour? Degree), for ordinary concrete about 1/6. Practice has shown that: 20 cm thick aerated concrete with micro-silica powder silica fume wall insulation effect is equivalent to 49 cm thick clay brick wall insulation effect, thermal insulation performance is also much better than 24 cm brick wall. This greatly reduces the thickness of the wall, accordingly, it will expand the effective use of the building area, saving the thickness of building materials, improve construction efficiency, reduce the cost of the project, reduce the weight of the building.
3. High strength
Experimentally, the compressive strength of silica fume silica fume for aerated concrete is more than 25 kg/cm2, which is equivalent to the compressive strength of 125 clay bricks and gray sand bricks.
4. Good seismic performance
In the magnitude of 7.8 Tangshan Fengnan and other places in the earthquake, according to the post-earthquake investigation, aerated concrete with micro-silica silica fume silica fume building with only a few new cracks, while the brick structure of the building all almost collapsed, so that the two not far from each other, the same structure and different materials in the building to form a stark contrast. Analysis that this is because of aerated concrete with micro-silica powder silica fume has a light weight, good overall performance, small inertia force during earthquakes, so it has a certain seismic capacity. This will be of great benefit to our earthquake-prone country.
5. Good processing performance
Silica fume for aerated concrete has good processing performance. It can be sawed, planed, nailed, milled and drilled. And it can add steel reinforcement in the manufacturing process. It brings great convenience and flexibility to the construction.
6. Silica fume for aerated concrete has certain high temperature resistance
Aerated concrete at a temperature of 600 ℃ or less, its compressive strength slightly increased, when the temperature is about 600 ℃, its compressive strength is close to the compressive strength at room temperature, so as a building material of aerated concrete fire performance to reach the national level of fire standards.
7. Aerated concrete with microsilica powder (silica fume)sound insulation performance is good
From the aerated concrete pore structure can be seen, due to the internal structure of aerated concrete like bread, uniformly distributed with a large number of closed pores, so it has a general building materials do not have the sound-absorbing properties.
8. Favorable to mechanized construction
As far as the current situation is concerned, precast aerated concrete assembled slabs can save the finished product stacking site; save masonry labor; reduce the wet work; speed up the site construction progress and improve the construction efficiency.
9. Strong adaptability of micro-silica powder and silica fume for aerated concrete
It can be customized according to different local raw materials and conditions. Raw materials can be selected from river sand, fly ash, mineral sand, silica fume silica fume, etc., according to local conditions. And it can be utilized as waste, which is beneficial to environmental protection and really turns waste into treasure.
Therefore, aerated concrete with micro silica fume silica fume has many advantages and cost-effective, is widely used in the building materials industry, from large to key projects, as small as the current private housing.