Bituminous Surfacing Options for Low Volume Roads Constructed by Labour-Based Methods
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Since labour-based road construction was introduced on a large scale with the Rural Roads Access Programme in the early 1970’s, this and all similar programmes throughout Africa and elsewhere have concentrated on earth- and gravel road construction and improvement.
The Gundo Lashu programme in Limpopo Province, South Africa, which started in 2001 was designed along the same lines. However, it soon became apparent that continuing with gravel road construction would not be sustainable for various reasons (most gravel sources not meeting specifications for good wearing course gravel resulting in high maintenance costs due to corrugation and ravelling, depletion of and uneconomical use of existing gravel deposits, dust pollution particularly in built up areas etc.). A life cycle cost analysis conducted by CSIR (Council for Scientific and Industrial Research, South Africa) showed that constructing to a low volume sealed road standard in most cases would be more cost effective (Paige-Green, P and Cassiem, I. 2003. Alternatives to Conventional Gravel Wearing Courses on Low Volume Rural Roads: Phase 1. Pretoria: CSIR-Transportek. (Contract Report CR-2003/30)).
Ongoing contracts were revised to include construction ofa proper base layer and bituminous surfacing and the contractors given additional training in the required construction techniques. This posed new challenges in terms of workmanship, quality assurance and adherence to specifications and efforts are continuing toensure quality of the works in line with the current specifications and public demand.
The purpose of this article is to share information with other labour-based practitioners who may want to go in the same direction as the Gundo Lashu programme.
The Gundo Lashu programme in Limpopo Province, South Africa, which started in 2001 was designed along the same lines. However, it soon became apparent that continuing with gravel road construction would not be sustainable for various reasons (most gravel sources not meeting specifications for good wearing course gravel resulting in high maintenance costs due to corrugation and ravelling, depletion of and uneconomical use of existing gravel deposits, dust pollution particularly in built up areas etc.). A life cycle cost analysis conducted by CSIR (Council for Scientific and Industrial Research, South Africa) showed that constructing to a low volume sealed road standard in most cases would be more cost effective (Paige-Green, P and Cassiem, I. 2003. Alternatives to Conventional Gravel Wearing Courses on Low Volume Rural Roads: Phase 1. Pretoria: CSIR-Transportek. (Contract Report CR-2003/30)).
Ongoing contracts were revised to include construction ofa proper base layer and bituminous surfacing and the contractors given additional training in the required construction techniques. This posed new challenges in terms of workmanship, quality assurance and adherence to specifications and efforts are continuing toensure quality of the works in line with the current specifications and public demand.
The purpose of this article is to share information with other labour-based practitioners who may want to go in the same direction as the Gundo Lashu programme.