Raw Material
from silicate cement clinker and fly ash, plus proper amount of gypsum after mixing. Code P.f
Any hydraulic gelling material made of silicate cement clinker, fly ash and appropriate amount of gypsum, called flourish silicate cement, code P.f. The participation of fly ash in cement is 20% to 40% by mass percentage. Allows 1/3 of the particle blast furnace slag that do not exceed the total amount of mixed materials. At this time, the total amount of mixture can reach 50%, but the amount of pulverized coal gray is still not less than 20% or more than 40%.
Features
The cement structure is relatively dense, the inner ratio is small, and the adsorption capacity of water is much smaller, and the water consumption of cement hydration is small, so The dry shrinkage of fly ash cement is small, and the crack resistance is good. Further, similarly to the cement of the general doped mixture, low hydration heat, strong corrosion resistance.
Performance
The uniqueness of the flyshite cement is as follows:
(1) Early strength low-end strength enhancement rate: fly ash cement The early strength is low, and the increase in early strength decreases with the increase of the increase in the ceremonial grease. Because the glass body in the fly ash is extremely stable, the fly ash particles are very slow and the rate of failure of Ca (OH) 2 is very slow, so the strength development of fly ash cement is mainly reflected in the later period. The late intensity increase rate is large, and even the late intensity of the respective silicate cement.
(2) is good, and the dry shrinkability is small: due to large fly ash particles, it is closed, and the inner surface area and monoena adsorbed water, so that the fly ash cement is Sex, small dry shrinkability, high tensile strength, good anti-crack performance. This is the obvious advantage of fly ash cement.
(3) The corrosion resistance is good: the flysh cement has higher anti-fresh water and anti-sulfate corrosion capacity, due to the formation of water formed in the active SiO2 and Ca (OH) 2 in the fly ash The limit concentration (i.e., liquid phase alkalinity) required (i.e., liquid phase alkalinity) is much lower than the lower limit concentration required for the hydrated silicate balance in the conventional silicate cement, so that in the fresh water, the leaching rate is remarkable Reduce, thereby increasing the corrosion resistance of cement resistance and anti-sulfate.
(4) Hydrogen and low: the hydration speed of fly ash cement is slow, low hydration heat, especially when the coal ash doping is large, the hydration heat reduction is very obvious.
Silicate cement
Any silicate cement clinker mainly calcium silicate, 5% or less limestone or granulated blast furnace slag, a proper amount of gypsum The hydraulic gelling material is collectively referred to as Portland Cement, which is known as Portland cement.
Classification
Silicate cement is divided into two types, no mixed materials, called type I silicate cement, code number P · I; blending does not exceed cement quality 5% limestone or granulated blast furnace slag mixture is called II silicate cement, code p · II.
Mineral composition
The main mineral composition of silicate cement is: trical calcium silicate, dioxcium silicate, trical calcium aluminate, ferro-aluminate. The silicate triester determines the strength of the silicate cement for four weeks; the calcium silicate is four weeks to play strength, about one year to achieve three weeks of three weeks of silicate; aluminate three calcium strength Play faster, but low strength, its intensity of silicate cement from 1 to 3 days or slightly longer; the strength of iron-aluminate four calcium is faster, but the strength is low, the silicon The intensity contribution of the acid salt cement is small.