JOINTS IN CONCRETE PAVEMENTS

This paper was presented at session 19 - pavement design 1. Increasing traffic loads and volumes, the need for low maintenance pavements and some concern about the cost and availability of bituminous materials has resulted in renewed interest in concrete roads. Significant lengths of plain, reinforced and continuously reinforced concrete roads have been built in Australia since 1970. Joints are a critical factor in concrete road performance. Poor performance of joints in some of our 30- to 50- year-old pavements has resulted in doubts about the suitability of concrete for roads. The elimination of wide expansion joints, a greater appreciation of the role of the sub-base, better sealant materials and improved design techniques, has led to vastly improved jointing systems. Current jointing practice is reviewed in this paper. First, the necessity for joints is discussed. The magnitude of movement at joints is analysed and methods of accommodating this movement are presented. Load transfer across joints is discussed, together with the properties of current joint sealants. Slab reinforcement is essentially determined by the jointing system employed, therefore plain, reinforced and continuously reinforced concrete pavements are also considered. (TRRL)