Ultra Thin Continuously Reinforced Concrete Pavement Development in South Africa

Abstract

Ultra thin continuously reinforced concrete pavements (UTCRCP), in literature also referred to as Ultra Thin Heavy 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 for use as a road strengthening measure by constructing experimental sections of 50 mm UTCRCP directly on top of both natural gravel and cement-treated natural materials. During the experiment the composition of the UTCRCP layer was varied in terms of mix design, steel fibre type and content, reinforcing steel mesh diameter and spacing. To date a total of 10 experimental sections have been tested using the Heavy Vehicle Simulator (HVS) and rendered structural lives that varied from 5 million to 90 million equivalent standard (80 kN) axles on medium to weak support structure. The results obtained were then evaluated through 3D-finite element modelling and the design was refined using laboratory tests. The refined UTCRCP design was then subjected to further HVS testing. The paper discusses the above process in more detail.