Stabilisation is the improvement of a soil or pavement material usually through the addition of a binder or additive. The use of stabilisation means that a wider range of soils can be improved for bulk fill applications and for construction purposes. The most common method of stabilisation involves the incorporation of small quantities of binders, such as cement, to the aggregate.
Stabilisation is used widely in both the construction of new roads and the rehabilitation or recycling of existing roads worldwide. It is used partly as a response to increasing traffic volumes and axle loadings that contribute to premature pavement failures, and partly where other roading materials are unavailable or the cost of material cartage is prohibitive.
The advantages of using in situ stabilisation techniques to upgrade or recycle existing materials in deteriorated pavements include cost savings of between 30 and 50%, faster rehabilitation, maximisation of materials, and reduced noise and dust pollution.*
Compared to other rehabilitation alternatives, in situ stabilisation also saves on landfill space as excavated materials do not need to be disposed of, and minimises the quarrying of replacement materials, which are finite resources.
The other benefits of using cement stabilised roading include reduced rutting, the ability to produce smoother and longer lasting riding surfaces which result in lower fuel usage for transportation, a reduction in the layer thickness and lower maintenance. Recent applications of cement stabilisation in New Zealand have taken place on SH16 in Rodney, and between Hicks and Poverty Bays on SH35.
By allowing premium aggregate to be preserved, and by using marginal aggregate, cement stabilisation’s ability to prolong the service life of New Zealand’s roading network is completely in tune with the principles of sustainable development.
*Wilmont, T. D. (1991). The recycling opportunities in the effective management of road pavements. Proceedings of the Local Government Engineering Conference, Hobart, Australia.