influence of environment on microsilica for concrete-pg电玩城

microsilica - also known as silicon micropowder - also known as silica fume - or silica ultrafine powder, which is rapidly oxidized and condensed by the sio2 and si gases generated during the smelting of ferrosilicon and industrial silicon and oxygen in the air. an ultrafine siliceous powder material formed.

physical and chemical properties of microsilica:

1. microsilica : appearance is gray or gray-white powder, refractoriness >1600 ° c. volume density: 200-250 kg / m3.

2. the fineness of microsilica : the fineness of silica fume is less than 1μm, accounting for more than 80%, the average particle size is 0.1-0.3μm, and the specific surface area is 20~28m2/g. its fineness and specific surface area are about cement. 80 to 100 times, 50 to 70 times the fly ash.

3, particle morphology and mineral phase structure: in the formation process of silica fume, due to the surface tension in the process of phase change, the formation of amorphous phase spherical particles, and the surface is relatively smooth, and some are multiple circles agglomerates in which the spherical particles are stuck together. it is a kind of volcanic ash material with large specific surface area and high activity. the material with micro-silica powder can play a role of lubrication.

effect of environmental conditions on the carbonization rate of microsilica fume concrete:

(1) light and temperature. concrete carbonation is directly related to light and temperature. as the temperature increases, the carbonization reaction and the co2 diffusion rate increase, so the carbonization rate increases. the direct sunlight accelerates its chemical reaction and accelerates carbonization.

(2) relative humidity. the relative humidity determines the degree of saturation of the pore water. carbonization is a liquid phase reaction, and it is difficult to carbonize concrete in air having a relative humidity of less than 45% (dry state); concrete in a humid air having a relative humidity of more than 95% or in water is difficult to carbonize due to small gas permeability. in the range of ambient relative humidity of 45%-95%, as the relative humidity of the environment increases, the carbonization rate of concrete decreases.

(3) co2 concentration in the environment. the higher the co2 concentration, the faster the carbonization rate. it is generally believed that the carbonization rate of concrete is proportional to the square root of the co2 concentration.

microsilica is an excellent material with broad application prospects in high-tech fields at home and abroad, and can be widely used in chemical, metallurgical and other industries. used in cement or concrete to improve the performance of cement or concrete, and to prepare special concrete or composite cement with super high, high strength, wear resistance, erosion resistance, corrosion resistance, penetration resistance, frost resistance and early strength to adapt to oil field solids. special requirements for wells, offshore oilfield drilling platforms, seaport terminals, railway bridge highways, airport runways, tunnels and urban high-rise buildings; used in rubber to improve the ductility, tear resistance and tensile strength of rubber; used in refractory materials and ceramic products to effectively improve the strength and durability of the product.