INFLUENCE OF BLAST-FURNACE CEMENTS ON DURABILITY OF CONCRETE STRUCTURES

Results of investigations in laboratory-scale work as well as long-term experience in practice indicate the special qualification of blast furnace cements, due to their high resistance against alkali-aggregate reaction, sulfate attack and diffusion of chlorides into concrete. Recent research has also shown the high binding capacity of chlorides in blast furnace cement pastes A further aspect of importance for corrosion protection of reinforcement is the comparatively low electrical conductivity of concrete made with blast furnace cement. Because of their low heat of hydration, blast furnace cements help to prevent cracks in mass concrete structures resulting from temperature stresses at early ages. With increasing content of granulated blast furnace slag in cement, the content of capillary pores in the mortar matrix decreases and Inter age strength of the concrete increases. This provides greater reserves with respect to concrete durability.