Portlandtsement 500 D0

In the JSC Qizilqumsement enterprise are issued a portlandtsement 500 D0

The grinding subtlety, water requirement, skhvatyvaniye terms, uniformity of change of volume and durability (brand) belong to the main properties of a portlandtsement (GOST 10178 — 85): cement. If necessary estimate also other properties: density and bulk density, a thermal emission, firmness in various conditions of the environment, etc.

Grinding subtlety — one of the factors defining speed of curing and durability of a cement stone. The usual portlandtsement is crushed quite thinly — the rest on a sieve No. 008 (4900otv/cm2) should not exceed 15% that corresponds to the specific surface of cement 2500... 3000 em2/g.

Water requirement of a portlandtsement is characterized by an amount of water (% of mass of cement) which is necessary for obtaining the cement test of normal density, i.e. in advance set standard plasticity determined by immersion in dough of the cylinder of a pestle of the device of Vick. Water requirement depends on mineral composition and a subtlety of a grinding of cement and fluctuates within 22... 26%.

Terms of a skhvatyvaniye and uniformity of change of volume of cement define on the test of normal density. The beginning of a skhvatyvaniye of the cement test has to come not earlier than 45 min., and the end of a skhvatyvaniye — tie is later than 10 h. Terms of a skhvatyvaniye determine by Vick's device by immersion of a needle of this device in dough of normal density. For obtaining normal terms of a skhvatyvaniye at a grinding of clinker enter additive of two-water plaster, and in case of need — special additives — delay mechanisms or accelerators of a skhvatyvaniye.

Process of curing of a cement stone is followed by volume deformations: swelling when curing in water, shrinkage when curing on air. These inevitable changes of volume are considered in production of construction works, providing the device of shrinkable seams. Uneven change of volume of a cement stone when curing is connected with existence in clinker of free oxides of calcium and magnesium which at hydration extend, causing local deformations. By the standard uniformity of change of volume is determined in the samples flat cakes made of the test of normal density which in 24 h preliminary curing boil 3 h in water. Flat cakes should not be deformed, on them radial cracks are not allowed.

The cement which does not have uniformity of change of volume cannot be applied in construction.

Other goods: cement, slate, slag stones, plates, brick, electrodes, crushed stone.