PROBLEMS AND FAILURE OF ASPHALTIC CONCRETE WEARING SURFACE CAUSED BY TRANSVERSE SAW CUT JOINTS

Abstract

This paper recommends construction technique for asphaltic concrete wearing surface without using transverse saw cut sealed joints. It points out that the transverse saw cut joints are the problems and causes for the observed failure of asphalt wearing surfaces seen in present day US highways. The paper presents the first observed failure of this type of joints on a 17-km long concrete bridge expressway in Bangkok, Thailand, 40 years ago. Since that lesson learnt, no saw cuts have ever been used on the pavement construction in Thailand with positive results. Presently in the US and elsewhere, saw cut seal joints are still used by some sectors of engineers, despite the observed failure of the asphalt wearing surface all over the country wherever the transverse saw cuts are used. This paper demonstrates the pictures of typical failure seen on actual structures. Pictures of good pavements without using transverse saw cuts are also shown for comparison. Brief discussions of the adverse effects caused by the saw cuts are given.