An investigation into the benefits and risks of the integration and application of Reclaimed Asphalt (RA) and Warm Mix Asphalt (WMA) technology into the South African asphalt industry

Stander, A. H. (2014-04)

Thesis (MScEng)--Stellenbosch University, 2014.

Thesis

ENGLISH ABSTRACT: Hot Mix Asphalt (HMA) plays a large role in the transportation infrastructure and is used to construct highways, runways, parking areas, foot paths and cycle paths. Asphalt is thus being produced in massive amounts around the world. The latest figures on asphalt production indicate that 1.6 trillion metric tonnes of asphalt are produced annually worldwide. This vast quantity of asphalt produced annually has a significant effect on the environment, economy and the surrounding society. According to Mike Acott from the National Asphalt Pavement Association (NAPA) the key strategy to improve HMA is to continuously strive to improve the health safety and environmental practices of HMA. He also emphasises the importance of engaging improvements and innovation in the design and operation phases of HMA as it will result into more health, safety and environmental benefits. (Acott, 2007) It is thus important to improve the sustainability of HMA as it will be used for generations to come. The purpose of this study is to investigate the potential benefits and risks of applying new technology to the current methods of design and construction of asphalt by the South African asphalt industry. The technologies that are investigated in this study are Warm Mix Asphalt (WMA) technology and the use of Reclaimed Asphalt (RA). WMA is asphalt that is designed to be manufactured at a lower temperature than HMA. RA is the use of recycled asphalt material in Hot Mix Asphalt (HMA) thus replacing virgin aggregate and virgin bitumen with recycled components. Both these technologies can have an effect on the sustainability of HMA. This study investigates the benefits and risks of the integration and application of WMA technology and RA into HMA industry in South Africa. The study uses interviews along with environmental and cost analyses to investigate this integration. The findings show that these technologies have definite environmental and cost benefits and that the magnitude of these benefits cannot be ignored. The current use of these technologies is a cause for concern as they are used in limited projects and limited authorities have warmed up to the use of these technologies. The risks involved in using these technologies are caused by a lack of experience and knowledge of these technologies which is aggravated as there are no standard specifications for their use. It is important that the right strategy is put into place to integrate these technologies into the South African asphalt industry in such a way that minimal risk and monetary losses are achieved.

AFRIKAANSE OPSOMMING: HMA speel 'n groot rol in vervoer-infrastruktuur en word gebruik om paaie, aanloopbane, parkeerareas, voet en fiets paaie te bou. Asfalt word dus wêreldwyd in groot hoeveelhede geproduseer. Die nuutste syfers toon dat 1.6 triljoen kubieke meter asfalt jaarliks wêreldwyd geproduseer word. Hierdie groot hoeveelheid asfalt wat geproduseer word het ‘n beduidende effek op die omgewing, ekonomie en die omliggende gemeenskap. Volgens Mike Acott van die Nasionale Asfalt Plaveisel Assosiasie (NAPA) is die voortdurende strewe om die gesondheids, veiligheids en omgewings impakte van HMA te verminder die sleutel-strategie om HMA te verbeter. Hy beklemtoon ook die belangrikheid om verbeterings en innovering in die ontwerp en bedryf fases van HMA aan te bring wat kan lei tot meer veiligheids, gesondheids en omgewings voordele. (Acott, 2007) Dit is dus belangrik om die volhoubaarheid van HMA te verbeter as dit bewaar wil word vir toekomstige geslagte te kom. Die doel van hierdie studie is om die potensiële voordele en risiko's van die gebruik van nuwe tegnologieë op die huidige ontwerp en konstruksie metodes in Suid-Afrika se asfalt bedryf te ondersoek. Die tegnologieë wat in hierdie studie ondersoek word is Warm Mengsel Asfalt (WMA) en die gebruik van Herwonne Asfalt (RA). WMA is asfalt wat ontwerp is om teen ‘n laer temperatuur as konvensionele HMA vervaardig te word. RA is die gebruik van herwinde asfalt in HMA wat lei tot die besparing van nuwe aggregaat en bitumen. Beide hierdie tegnologieë kan 'n invloed op die volhoubaarheid van HMA hê. Hierdie studie ondersoek dus die voordele en risiko's van die integrasie en gebruik van WMA en RA tegnologie in die HMA-industrie in Suid-Afrika. Die studie maak gebruik van onderhoude asook omgewings en koste impak analises om hierdie integrasie te ondersoek. Die bevindinge in die studie toon aan dat hierdie tegnologie definitief voordelig is vir die omgewing en die ekonomie en dat hierdie voordele groot genoeg is om nie geïgnoreer te word nie. Die huidige gebruik van hierdie tegnologieë is 'n rede vir bekommernis, want dit word slegs in ‘n paar projekte aangewend en daar is slegs ‘n paar owerhede wat die tegnologieë ondersteun. Die risiko's wat betrokke is in die gebruik van hierdie tegnologieë word veroorsaak deur 'n gebrek aan ondervinding en kennis van die tegnologieë wat verder vererger word deur die gebrek aan standaard spesifikasies vir die gebruik daarvan.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/86323
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