CALIBRATED MECHANISTIC DESIGN PROCEDURE TO PREVENT TRANSVERSE CRACKING OF JOINTED PLAIN CONCRETE PAVEMENTS

Abstract

A comprehensive design procedure for jointed plain concrete pavements to control transverse cracking has been developed. A rigorous mechanistic procedure to compute the slab edge stress at the critical location was developed. The design procedure directly considers the following design components: - slab thickness, length .and width to prevent repeated load and thermal curling stress related cracking - shoulder lane joint load transfer system - base support of the slab - transverse joint load transfer system to prevent faulting - transverse joint sealant system to prevent spalling - subdrainage of the cross section. The analysis system can include a two or three layer system subjected to different axle load configurations: single, dual, dual-tandem, and tridem. Different boundary conditions or shoulder types can be analyzed including bituminous, tied concrete, or widened outer lane. Thermal curl stress is considered assuming a linear temperature differential through the slab thickness, which makes it possible to directly consider its effect on joint spacing. The structural thickness and length design of the concrete slab is based on a fatigue damage analysis. The main improvement in this procedure is the development of a fatigue relationship based on field slab tests. Selected sections of the AASHO Road Test and the accelerated traffic tests performed by the Corps of Engineers were utilized in developing the above relationship. A user friendly computer program was developed that computes fatigue damage and estimates transverse cracking as well as joint faulting, joint spalling and PSR.