Alkali-activated cements for ground improvement

The paper studies alkali-activated (AA) slag cements for soil stabilisation, as alternatives to traditional binders such as Portland cement or lime. A number of alkali activators were considered, containing also a range of salts and a material retrieved from waste (Paper Sludge Ash, PSA). The results are discussed in terms of unconfined compressive strength (UCS) at two different curing times. In general alkali-activated cements based on the use of alkali salts only had a modest performance in terms of strength improvement; a material that showed promise however as slag activator was the PSA. Further analysis is recommended in order to gain a better understanding of the complex mechanisms involved towards engineering uses for soil stabilisation.