This paper presents results regarding the potential of lignosulfonate (LS) to control the swelling of expansive soil.
One-dimensional swell tests were performed on untreated and LS-treated remoulded samples of Australian expansive
soil from the state of Queensland. The test results indicated that LS has significant influence on the swelling
behaviour of this expansive soil. The results were compared with those of identical cement-treated soil samples, and
it was found that LS could be a economical and environmentally friendly alternative to traditional alkaline additives.
In addition, the behaviour of LS-treated specimens during repeated freezing and thawing cycles was measured. The
results indicated significant improvement in the percentage mass loss in LS-treated specimens compared with cementtreated
specimens. The microstructural analysis of the untreated and the LS-treated samples showed soil surface
area reduction in the treated specimens, which in turn reduced the affinity of the specimens towards moisture uptake,
resulting in a reduction in the swell potential of the otherwise expansive soil. The use of LS as a novel non-traditional
stabiliser for expansive soil appears to be a viable solution in view of the sustainable use of waste by-products and