Author(s)

Z J Yi, Q G Yang & K Peng

Abstract

Fracture analysis of cement concrete pavement and a new idea, of pavement design Z. J. Yi, Q. G. Yang & K. Peng Department of Bridge & Structure Engineering, Chongqing Jiaotong University, P.R. China Abstract A new concept of \“transition layer” is introduced in this paper. The \“transition layer” is located between the surface course and the base course. The research of \“transition layer\“, from the viewpoint of fracture mechanics, shows that there exist a large number of defects and cracks in the ”transition layer” before the external service loads act. Theoretical explanation and experimental research indicate that the pavement-base interface and transition layer as well as their damage impose grave influence on the pavement failure, and through improving the condition of interface could the strength and fatigue strength (or life) be promoted. According to the theoretical and experimental conclusions, the author put forward a new idea of pavement design based on the principle of fracture mechanics. 1 Introduction According to the traditional theory of strength, the typical pavement theoretical models involve the Winkler’s foundation slab model, the elastic half-space foundation slab model and several other models [l]. No matter what model is employed, it is assumed that the surface course and the base course are smoothly contacted along their interface, which implies that the interaction between the surface course and the base course is vertical only, there allows relative tangential slide with negligible tangential shear. The traditional pavement theory takes the flexural strength and the flexural fatigue strength as the main design parameters. Once there appear visible cracks in the pavement, the pavement is considered to have been cracked and failed. In other words, the appearance of fracture cracks marks the critical state of the structural destruction of concrete surface course. However, the actual cement concrete pavement structures in different countries are always constructed by casting the cement concrete on the base

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