BLASTFURNACE CEMENT Technical specifications

Blastfurnace cement CEM III /A 42,5 N complies with the European Union norms, EN 197-1, CEM III/A 42,5 N and therefore we can guarantee the highest quality of our product.

Cement constituents

CEM III/A 42.5 N is more environmentally friendly material. Its usage proved to reduce costs, save raw materials and energy for production, and therefore protect our nature.

Hydration

Blastfurnace cement usage causes lower heat of hydration and conduces to pore-blocking effect. Cement paste has a less open hydrate structure and lower permeability in comparison to similar type of concrete containing Portland cement. This leads to high resistance to sulfates, chlorides, aggressive chemicals, acids attacks and penetration of corrosion-inducting chlorides.

Thermal cracking

Concrete with admixture of blastfurnace cement produces lower heat of hydration than Portland cement. It largely limits temperature rise in thick-sectioned pores, critical temperature differences and restricts early age thermal contraction cracking.

Alkali silica reaction

In most cases we can experience alkali silica reaction in concrete between the alkalis in cement paste and silica situated in most of the aggregates. Blastfurnace cement minimizes this risk by consuming alkalis in hydration process, reduces pore size, mobility of alkali and overall reduces alkali in a system.

Sulfate and acid attack

This attack happens when concrete comes to contact with sulfates in water. Sulfates from water react with C3A and Ca(OH)2, which are part of the cement and create expansive crystalline product, which when expanding cracks the concrete. The cracks allow more sulfates come into concrete and speed up process of cracking.

CEM III/A 42,5 N has higher resistance to sulfate attack since it contains less alumina, Ca(OH)2 and does not contain C3A, which means that it guarantees less penetration of sulfate ions.

Strength development

Slower gradual strength leads to better workability, higher compressive and flexural strength. The concrete using CEM III/A 42.5 N at early age has lower strength in comparison to concretes made with CEM I 42,5 R and CEM II/ B-S 42,5 R. But after 28 days CEM III/A 42,5 N strength overcomes strength of CEM I 42,5 R and almost acquires the same strength as the CEM II/ B-S 42,5 R.

Environmental advantages

According to Worldcement.com magazine, blastfurnace cement is marked as sustainable world building material, not only for perfect technical features, but also for consideration of environmental issues.

Reduction of CO2 and other toxic emissions

Typical production of CEM I results in emission of 930 kg of CO2/t of cement, where 50 % is from decarbonation of limestone, 40 % from consumption of fossil fuels and 10 % from electricity production used in the process. Ground granulated blastfurnace cement (GGBS) production normally releases 35 kg of CO2/t of GGBS. This presents less than 4 % from carbon release of normal cement production.

GGBS also reduces other toxic emissions which cause various diseases and therefore it is also protecting our health.

Save natural resources

The production of each tone of normal cement requires 1,6 t of raw material. GGBS with using a blastfurnace slag avoids depletion of natural sources and makes the cement more sensitive to the environment.

Solar reflectance

The concrete that uses blastfurnace cement reflects more sun energy, reduces global warming and contributes to the reduction of heat island effect in urban areas. Studies in US confirm increased by 20 % sun reflection effect when blastfurnace cement is used. Subsequently it also reduces cost for lighting at night and makes the roads more visible and safer. Combination of environmental, economic and health advantages makes blastfurnace cement a unique material which is also confirmed by the leading sustainable building codes (LEED, BREEAM).