The Re-use of Existing Bituminous Stabilised Materials for the Rehabilitation of National Route 7 - Case Study
Authors: Glynn Llewellyn1, Azni November2, Craig Bradley3
Conference: 13th Conference on Asphalt Pavements for Southern Africa
Date: October 15-18, 2023
1 Knight Piésold
2 Western Cape Government
3 Hatch Africa
SYNOPSIS
Western Cape Government’s (WCG) Department of Infrastructure recognised the need to rehabilitate the existing N7 (TR11/1) in Cape Town between the Bosmansdam Interchange (km 2.00) and the Melkbosstrand Interchange (km 18.02). WCG tasked the project team with developing a cost-effective, sustainable solution that would minimize disruptions to the traffic and local community during the rehabilitation of the N7. In response, an innovative approach to reprocess the existing bitumen stabilised material (BSM), which behaved somewhere between a published BSM and cement stabilised material, as well incorporating the milled off asphalt for use in the base layer was proposed. The proposal effectively meant re-processing the base material for a third time thereby providing a “third-life-cycle rehabilitation”.
This paper will focus on the materials investigation undertaken on the project that led to the design proposal, design process followed at the time, pavement life cycle evaluation and relook at the design post publication of the TG 2, 2020 BSM transfer function.
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