Proper mix design, adequate thickness, and diligent constructionand control techniques are prerequisites to the successful performance of a cement-treated base (ctb) layer and, in turn, the entire pavement structure. A critical review and verification of the structural design procedures are presented. Highlighted are the structural characteristics relevant to the design procedure and design criteria, including distress modeling. Structural characteristics paramount to the thickness design procedure are discussed. On the basis of those properties only the predominant failure modes of ctb and the governing failure criteria are discussed. A short description highlighting the failure criterion of various design methods, six in all, is also discussed. Those methods vary widely in their use of mechanistic principles: for example, three methods are strictly fatigue-based and two others rely on precedent and experience. The validity of each design procedure is assessed by performance history of pavements in service, which is compiled from the literature. A coparison of ctb pavements for a typical sun-belt area for a range of traffic indicates that the structural thicknesses mandated by the six design procedures are different. The most conservative design is approximately 30% thicker than the least conservative design. This paper appears in transportation research record no. 1288, Geotechnical engineering 1990.
Abstract