This paper examined conceptual approaches for incorporating shrinkage cracking in the mix design of cement stabilised pavements. The approaches were discussed in three levels depending on their sophistication. The Level 3 approach, which is amenable to routine calculations, was elaborated in some detail on the basis of the author's research on this topic. Many assumptions were made due to lack of factual data on shrinkage of stabilised materials under variable climatic conditions. The field pavement behaviour was idealized so that it achieves an equilibrium moisture content beyond which the pavement moisture content fluctuates seasonally around this equilibrium value. The relationship between the effective shrinkage strain and the moisture loss was idealized in linear or bi-linear models. The effective strain was defined as the free shrinkage minus the creep strain, which is an important component in shrinkage of cemented materials. The concept of cracking potential was introduced quantitatively, which was then used to compute the cracking severity giving crack spacing and likely crack widths. The application of Level 3 approach was elaborated using a hypothetical example. Further research is needed to make the conceptual approaches reliable for application to mix design of cement stabilised pavement materials. (a) For the covering entry of this conference, please see ITRD abstract no. 0612AR242E.
Abstract