Paper and Presentation by Anna-Carin Brink from ASCP 4th Concrete Pavements Conference 2017
The aim of this paper is to present an overview of the routine maintenance conducted on continuously reinforced concrete pavement (CRCP) sections on two of the national routes in South Africa. The majority of the freeway system in South Africa has been subdivided into contracts that are being monitored and managed by a main civil engineering contractor, appointed following standard tendering procedures. Simultaneously, on each Routine Road Maintenance (RRM) contract, the owner of the freeway system, the South African National Roads Agency (SANRAL) operates with the assistance of a consulting engineering team; also appointed following standard tendering procedures. The duration of a RRM contract is generally three years, with a maximum of eight years in exceptional cases. Generally, due to a lack of specialised expertise within the RRM contractor’s organisation, failed areas in concrete pavement sections are repaired with asphalt. These asphalt patches do not last long, which requires frequent re-repairing of certain areas. The number of asphalt patches in concrete pavement sections on National Route 3 (N3) in the vicinity of Pietermaritzburg, Kwazulu-Natal increased to such an extent that it warranted the compilation of a specialist sub-contract under the RRM contract. Jointed concrete pavement (JCP), as well as continuously reinforced concrete pavement (CRCP) sections were repaired during the subcontract. In this paper the focus will be on the repair of the CRCP sections. The only CRCP, of substance, that used to exist in South Africa, is the Ben Schoeman freeway; a section of National Route 1 (N1), between Pretoria and Johannesburg in Gauteng (with the upgrade of the Gauteng Freeway system, the length of road covered by CRCP has increased substantially). Local repair work to failed sections was required after 20 years of service. On the N3 it was possible to close off sections of the freeway to conduct the repair work and a conventional concrete mix could be used, however on the N1 the high traffic volumes on an already congested commuter route necessitated night work and the use of rapid-hardening concrete. This paper presents inter alia the background to the rehabilitation measures specified and an overview of the repair work conducted. The challenges that faced the subcontractors to repair concrete pavement sections, while keeping two lanes open to traffic at all times, are also highlighted.
KEYWORDS: ROUTINE ROAD MAINTENANCE, CONTINUOUSLY REINFORCED CONCRETE, RAPID-HARDENING CONCRETE, ACCOMMODATION OF TRAFFIC.