Traditional energy intensive cement production is making way for a new alternative that offers improved soil properties and stabilisation at a reduced financial and environmental cost.

Deep Soil Mixing (DSM) is an innovative technology that blends existing soils with cement grout creating ‘soil-crete’ columns underground. A research paper published on the Civil Engineering Journal identifies pozzolans and filler materials as possible supplements to DSM's predominant binders; Portland cement and Lime.

Mixing soil with a binder such as cement, fly ash or lime can enhance soil properties including strength, stability and stiffness. However, the inclusion of pozzolans including fly ash, silica fume, slag, rice husk ash, kaolin and metakaolin in treated soil strength also prove effective, low cost and sustainable.

The paper explains the binder reaction process and the potential to supplement or substitute traditional binders. Optimum percentage of the pozzolan was determined where improved strength peaked. As a result, the paper states “Aluminosilicate pozzolans perform better over siliceous pozzolans with Metakaolin (MK) identified as the most effective pozzolan for enhancing compressive strength.”

View the pozzolan test summaries here.