This report presents the results of a literature review carried out in 1996. It includes a discussion on the materials and reactions involved in lime and cement stabilisation. It describes the distinction between modified and cemented material behaviour and discusses the advantages and disadvantages of the two kinds of stabilisation. The report concludes that subgrade stabilisation should be restricted to soil modification as opposed to soil cementation.
Soil modification allows poor subgrade soils to be improved without the disadvantages and vagaries of cemented soil performance. Modified soil generally offers a modest increase in elastic modulus, and improved handling characteristics, e.g. increased resistance to water ingress and volume change. Conversely, cemented soils achieve a relatively high elastic modulus and consequently they attract a large proportion of the applied stress. This makes cemented materials vulnerable to fatigue failure and a subsequent loss of performance. Quantifying the loss of performance in a rational pavement design procedure is an extremely difficult task, and one that has not been satisfactorily addressed in the literature reviewed for this project.
Keywords: AUSTROADS, cemented, design, modified, New Zealand, pavement design, road, soil-cement fatigue, stabilisation, subgrade