Lime stabilisation of glacial clay : Barnes, G E; Reynolds, W S Highways TranspV36, N6, June 1989, P26–32

Abstract

Although lime stabilisation has been adopted in road building in Europe and the USA, only recently has it been used in the UK for capping layers. The paper examines the effect of lime stabilisation on the density, unconfined compression strength, moisture condition value, and modulus of a gravelly clay (glacial clay). A project to investigate the effects of initial moisture content, gravel content, lime content and compaction energy on the unconfined compressive strength is described. Moisture condition value and Proctor compaction tests were carried on a number of lime stabilised mixes. Results show that the strengths achieved are likely to make lime stabilisation suitable only for subgrade improvement of glacial clays, particularly those of law plasticity. Density is not a good measure of performance as it is affected by variable properties of the soil such as plasticity, moisture content and stone content. Strength is controlled by the initial moisture content, with an optimum for maximum strength. For wetter soils the strength is not increased significantly with increasing lime content, but for drier soils the stabilised matrix is more brittle with a moderate amount of gravel producing a weak, honeycombed structure. Glacial clays are sensitive to moisture content change because of their low plasticity and variable stone content.