The Challenging Rehabilitation of the Antwerp Ring Road in CRCP 2004 – 2005

The rehabilitation of the Ring Road of the city of Antwerp is the largest and most discussed road construction project undertaken in Belgium within the last decades. The Antwerp Ring Road is one of the most trafficked urban freeways of European importance. Six radial freeways are tying into it and traffic volumes on its busiest sections are nearing 200000 vehicles per day, 25% of which are heavy trucks. The dual carriageway of the Ring is 14.2 kilometers long. The number of lanes varies from four to seven in each direction. Along with 30 kilometers of access and exit ramps on the interchanges, the project comprises a total of 100 hectares of pavement requiring renewal and full recycling. Considering the economic importance of the Ring for the Port of Antwerp, the rehabilitation works envisaged a safe, modern and efficient Ring Road, having a low maintenance pavement with a service life of at least 35 years. Based on a Life Cycle Cost Analysis and a Multi Criteria Analysis, a continuously reinforced concrete pavement has been chosen for the main part of the Ring Road. The complete pavement structure is being renewed and consists of 23 cm of CRCP, a 5 cm thick bituminous inter-layer, 25 cm base of cement stabilized granulated asphalt rubble and 15 cm subbase of granulated lean concrete rubble. A fine exposed aggregate surface combines a good skid resistance with a low level of rolling noise. This project was also unique due to the extremely short execution period and because of the large scale of traffic alleviating measures. The construction period was split up into two main periods of 5 months each. The outer ring was reconstructed in 2004 and the inner ring in 2005. This provided the possibility to improve the organisation and the methods of execution during the second construction period based on the experience gathered during the construction first period. The paper describes the presently applied common practice in Belgium in general and highlights the most important innovative techniques (such as: a new type of terminal joint, the design and construction of CRCP with variable width on the auxiliary lanes), applied with regard to the execution of the CRCP on this project in particular. The paper further presents the technical consequences of the traffic alleviating measures (such as: the provisions of leave outs, the large scale recycling of broken-up material of the existing pavement) and the improvements made during the second construction period. The experience in designing and constructing this ambitious project will certainly contribute to a further development of the technique of CRCP in Belgium and in other countries.