ISTRA 40 and ISTRA 50 are normal-setting, fast-setting alumina cements with high strength at the early stage of setting.
In terms of production technology, chemical composition and hardening characteristics, it differs significantly from conventional calcium silicate cements such as Portland cement and slag cement.
ISTRA 40 consists mainly of calcium aluminates, which give it the following characteristic qualities
high early strength
fire resistance;
resistance to biogenic and sulfuric acid corrosion.
ISTRA 40 complies with the British standard BS 915 for high-aluminate cements and is subject to continuous monitoring in accordance with EN 196. The shelf life of ISTRA 40 cement is six months, provided it is stored in dry conditions.
ISTRA 40 is produced by the joint melting of bauxite and limestone in special furnaces.
Physical properties of the cement:
- Residue on the sieve at 90 microns < 5%;
- Blaine fineness of grinding about 3000-3500 cm2/g;
- Bulk density of about 1.15 g/cm3;
- Specific gravity 3.2 – 3.3 g/cm3;
- The fire resistance of cement is about 1270 degrees.
Corrosion resistance
High resistance to wastewater with extremely high friction strength and high resistance to biogenic sulfuric acid corrosion make ISTRA 40 cement an ideal material for the construction of sewage networks and water treatment plants.
Fire resistance
When heated, mortars and concretes based on ISTRA 40 release moisture slowly and continuously, which is why dehydration takes place without destroying the structure. At high temperatures (>10000 C), a ceramic bond forms between alumina cement particles and refractory aggregates. This makes ISTRA 40 an excellent choice as a binder for refractory concretes and masses.
Quality assurance
The production of ISTRA 40 cement is subject to strict quality control. Continuous quality monitoring of all components guarantees consistent performance. The manufacturing plant is certified according to EN ISO 9001 certificate No. CH99/0297, as well as EN ISO 14001 (environmental management system) certificate No. CH02/0862.
