Optimizing the steel fibre and mesh combinations used in repairing existing pavements with Ultra Thin Continuously Reinforced Concrete Pavements (UTCRCP)

Author(s): E.P. Kearsley, H.F. Mostert
Paper category: Conference
Book title: Concrete Repair, Rehabilitation and Retrofitting III (ICCRRR)
Editor(s): M.G. Alexander, H.-D. Beushausen, F. Dehn, P. Moyo
Print ISBN: 978-0-415-89952-9
Publisher: Taylor & Francis Group
Pages: 365- 366
Total Pages: 2
Language: English

As part of the National Highway renewal programme currently in progress in South Africa, full-scale experimental trial sections of Ultra Thin Continuously Reinforced Concrete Pavements (UTCRCP) have been constructed. The UTCRCP consists of a 50 mm thick layer of 90 MPa concrete containing approximately 100 kg/m3 of steel fibre as well as a steel mesh of 5.6 mm reinforcing bars at a spacing of 50 mm to 100 mm centre to centre. The UTCRCP can handle high deflections and it is intended for use as an overlay to rehabilitate weakened pavement structures. The design, construction and quality control of the material has proven to be a challenge. Pavement design engineers normally see concrete pavements as rigid pavements that fail in a brittle manner. The un-reinforced concrete pavements with closely spaced movement joints built in the past were rigid brittle structures, but the use of continuously reinforced concrete pavements, has resulted in both a reduction in the volume of concrete required for any given pavement, and a more flexible behaviour of the pavement. Optimization of the concrete mix composition through the use of modern superplasticizers and steel fibres can not only significantly enhance the flexural strength of the concrete, but also result in a more ductile failure. UTCRCP can result in a significant saving in the volume of material required for a pavement designed to take a given traffic load. Since 2006 researchers at the University of Pretoria have been involved with analyzing and testing materials for use in these pavements and in this paper an overview will be given of design, construction and quality control issues encountered. Conventional design procedures cannot be used to determine the required reinforcement diameter and spacing or suitable fibre content. This paper focuses on the optimization of the combination of mesh reinforcing and fibres in the UTCRCP.

Online publication: 2014
Publication Type: abstract_only
Public price (Euros): 0.00