Ultra thin continuously reinforced concrete pavement research in south Africa

Abstract

Ultra thin continuously reinforced concrete pavements (UTCRCP), in literature also referred to as Ultra Thin Reinforced High Performance Concrete (UTHRHPC), have been used in Europe successfully as a rehabilitation measure on steel bridge decks and reported on at the 5th International CROW workshop in Istanbul (2004). This concept has been explored further in South Africa constructing experimental sections of 50 mm UTCRCP directly on top of both natural gravel and cement-treated natural materials. The sections were tested using the Heavy Vehicle Simulator (HVS) and rendered structural lives that varied from 5 million to 90 million equivalent standard (80 kN) axles. Distress that developed indicated sensitivity to the bond between UTCRCP and the support, thickness of the UTCRCP layer, concrete strength, the development of cracks and the presence of water. In order to further explore the applicability of this concept under different conditions, use was made of 3D-finite element modelling of a pavement under a moving load.. The thickness of UTCRCP layer, placed on top of a support system with varying degrees of bonding, the presence of voids, varying concrete properties as well as the position of and different quantities of steel reinforcement were also modelled. The paper discusses the similarity of pavement response between HVS loading and modelling.