Ternary cements in Iceland
Producing cement in Iceland is a unique experience. The scarcity or even absence of traditional raw materials on this volcanic island requires some inventive thinking. In addition, exposure to water, particularly seawater, heavy winds and cold weather makes special demands on the concrete and hence, the cement used in construction. This led to the development of ternary blended cement, using locally-available pozzolans. Dr Guðmundur Guðmundsson, former manager of the Iceland State Cement Works, explains the development of ternary cements in the country.
An emerging technology shows that 50-70 per cent of Portland cement can be replaced with one or several complementary materials, such as coal fly ash, granulated blast furnace slag (GGBS), natural pozzolans, silica fume and rice husk ash with dramatic improvements in the properties of concrete. This can be achieved either by blending in a cement plant or during concrete batching.