The use of cement-treated materials, such as cement stabilized aggregate bases, subbases and subgrades treated with cement, lime or other materials, is common practice in many states in the United States and numerous other countries including Australia, France, Spain, and South Africa. Althougha great deal of research has been performed on the properties of these materials and their performance in the laboratory, limited research in the U.S. has been conducted to relate the properties of such materials to theirshort- and long-term performance in the field. The AASHTO Interim Mechanistic-Empirical Pavement Design Guide Manual of Practice (MEPDG) developedunder NCHRP Project 01-37A provides a methodology for estimating the response and performance prediction of pavements with cemented layers. However, the behavior of these materials differs substantially depending on the material type, the amount of cement, the position of the treated layer, environmental conditions during and after construction, and the traffic characteristics such as wheel load and tire inflation pressures. However, it isacknowledged that the mechanistic characterization of cement-treated materials and their principal modes of distress have not been adequately addressed in the current version of the MEPDG. There are also limited field andlaboratory data locally available that correlates the properties of thesematerials with their expected field performance. To address these aspects, this paper summarized the South African experience because it can provide a sound basis for future developments in this area.
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