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The majority of the road networks in developing countries and large percentages in most developed countries are currently unpaved. This results in the road surface being directly exposed to traffic and the environment with a consequent continual loss of gravel, which needs to be replaced at regular intervals. This has severe environmental and sustainability implications and is totally unacceptable in these respects in the long term. Alternatives to this need to be developed such that the materials are either protected against environmental loss or are treated to an extent that the annual loss is significantly reduced. The optimum solution is to pave all roads with either a bituminous or concrete surfacing such that the material imported into the road is preserved against loss by erosion and abrasion. This is, however, probably not financially viable in most developing countries. The alternative is to treat the materials in some way that will reduce the annual loss. Research has indicated that, firstly by selecting the most appropriate materials and secondly, by improving construction methods, significant reductions in material loss are possible. To supplement this, methods of chemical or physical treatment can be considered to minimize material loss. Essentially, the status quo is no longer sustainable and a paradigm shift in this respect is urgently necessary. The impact of the use of water during the construction and maintenance of unpaved roads should also not be neglected.
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AASHTO. (2008). T180: Moisture-density relations of soils using a 4.54 kg (10 lb) rammer and a 457 mm (18 in.) drop. Washington, DC: American Association of State Highway and Transportation Officials.
Bennett, C. R., Paterson, W. D. O. (2000). A guide to calibration and adaptation. In: The highway development and management series. international study of highway development and management (Vol. 5). Paris: World Road Congress (PIARC).
Committee of State Road Authorities (CSRA). (1990). The structural design, construction and maintenance of unpaved roads. Draft TRH 20. Pretoria: Department of Transport.
Giummarra, G. J., Martin, T., Hoque, Z., Roper, R. (2007). Establishing deterioration models for local roads in Australia. Proceedings of 9 th International Low Volume Roads Conference, Austin, Texas. Washington: Transportation Research Board.
Gourley, C. S, Greening, P. A. K. (1999). Performance of low volume sealed roads: Results and recommendations from studies in Southern Africa. Report PR/OSC/167/99. Crowthorne: Transport Research Laboratory.
Henning, T. F. P., Giummarra, G. J., Roux, D. C. (2008). The development of gravel deterioration models for adoption in a New Zealand gravel road management system. Land Transport New Zealand research Report 348. New Zealand: Wellington.
Highways Development and Management (HDM-4). (2000). World Road Association (Vols. 1–5). Paris, Washington, DC: World Bank.
https://www.cia.gov/library/publications/the-world-factbook/fields/2085.html. Retrived August 2013.
http://pubs.usgs.gov/gip/deserts/what/world.html. Retrived August 2013.
Jones, T. E. (1984). The Kenya maintenance study on unpaved roads. TRRL laboratory Report 1111. Crowthorne: TRRL.
Jones, D., Bolander, P., Paige-Green, P. (2013). New developments in selecting chemical treatments for gravel roads. Paper presented at 92nd Transportation Board Annual Meeting, TRB, Washington.
Leyland, R., Paige-Green, P. (2009). Minimising groundwater extraction for infrastructure construction. Proceedings of Ground Water Conference. Retrived November 2009. Stellenbosch.
Louw, K., Schoeman, S. (2004). Performance of sand seals in the Kruger National Park. Proceedings of 8th Conference Asphalt Pavements for Southern Africa (pp. 906–913). South Africa: Sun City.
Meigs, P. (1953). World distribution of arid and semi-arid homoclimates. In UNESCO: Reviews of research on arid zone hydrology (pp. 203–201). Paris: UNESCO.
MEA (Millennium Ecosystem Assessment) (2005). Ecosystems and Human Well-being: Wetlands and Water Synthesis. Washington, DC: World Resources Institute.
Overby, C. (1999). A guide to the use of Otta Seals. Oslo, Norway: Publication 93, Directorate of Public Roads.
Paige-Green, P. (1989). The influence of geotechnical properties on the performance of gravel wearing course material. PhD Thesis, University of Pretoria.
Paige-Green, P. (2011). Sustainability issues related to the engineering geology of long linear developments. Journal of Mountain Science, 8(2), 321–327. CrossRef
Paige-Green, P., Bennett, H. (1993). The use of sulphonated petroleum products in roads: State of the art. Proceedings Annual Transportation Convention (Vol. 4C), Pretoria.
Paige-Green, P., Pinard, M. I. (2012). Optimum design of sustainable sealed low volume roads using the Dynamic Cone Penetrometer (DCP). Proceedings 25th ARRB Conference. Perth, Australia.
Pinard, M. I., Paige-Green, P. (2013). A new approach for the optimal design of sealed low volume roads using the Dynamic Cone Penetrometer (DCP). 6thAfrica Transportation Technology Transfer (T2) Conference (pp. 187–203). Botswana: Gaborone. March 2013.
Sabita (2012). Bituminous surfacings for low volume roads and temporary deviations. Manual 10, South African Bitumen Association (Sabita), Cape Town.
Thornthwaite, C. W. (1948). An approach toward a rational classification of climate. Geographical Review, 38(1), 55–94.
van Zyl, G., Henderson, M., Uys, R. (2007). Applicability of existing gravel road deterioration models questioned. 9 th International Conference on Low-Volume Roads, Austin, Texas, June 2007.
Visser, A. T. (1981). An evaluation of unpaved road performance and maintenance. PhD Thesis, University of Texas, Austin.
- Sustainability Issues Surrounding Unpaved Roads
- Springer Berlin Heidelberg
- Chapter 11