1986

Häkkinen, Tarja

The study consists of a literal survey of the structure and properties of alkali-activated slag concrete and an experimental study of the properties of the so-called F-concrete. F-cement is finely ground glassy slag to be activated by a combination of alkali metal compounds and rendered consistent in its fresh state by means of lignosulphonates. Many investigations have been conducted in order to study the possibility of accelerating the strength development of slag when using activators other than Portland cement (or calcium hydroxide) or gypsum. Chemicals frequently used are strongly alkaline compounds such as hydroxide, sodium carbonate and sodium silicates. The results have not usually led to major industrial use. F-cement is developed in order to produce low porosity concrete. The water-cement ratio of a fluid F-concrete mix is about 0.35. According to the tests performed, typical properties of hardened F-concrete appeared to consist of high early strengths in accordance thermal treatment, continuous strength gain to advanced ages and good chemical resistance. Deformation properties and physical resistance did not differ much from those of the reference concrete made of Portland cement.