A Framework For The Appropriate Use Of Marginal Materials

There is a growing awareness of the socio-economic and technical reasons for developing rural infrastructures based on low volume sealed roads within the appropriate environments. There are significant challenges to be met, however, not only technically but also in convincing governments and funding agencies of the whole life economic advantages. The technical issues may be dealt with by taking on board the concept of appropriate or environmentally optimised design. Although the standard road design methods and standards remain largely appropriate for trunk roads, their applicability to low volume trunk roads and much of the secondary and feeder road network is questionable. The utilisation of locally available and task-suited pavement materials is a fundamental issue within the concept of appropriate design. Locally available materials may be out-specification with respect to standard sealed road design; however, the concept of fitness for purpose within a specific road environment may allow many of these non-standard materials to be designated both acceptable and suitable. Their use needs to be justified in terms of cost and engineering risk to sceptical consultants, government agencies and donors and a verifiable evaluation sequence will give credence to their investigation and use. The UK's Department for International Development (DFID) and others have funded, over a number of years, research on the selection and use of locally available "marginal" materials for road construction. These studies, based on both the construction and long term monitoring of full-scale trials as well as detailed investigation of selected sections on existing road networks, show that there is considerable scope for relaxation of current material selection standards. A recent review of much of this research has led to the development of an evaluation framework that recognises the needs of the road design environment. The approach is founded on a synthesis of current knowledge and the practical experience gained over many years by TRL and others working largely within tropical and sub-tropical regions. It is suggested that the principles of the approach, which are outlined in this paper, are also valid for other regions and also for many different types of materials. For the covering abstract see ITRD E135448.

• Authors:
  • COOK, J R
  • GOURLEY, C S
• Publication Date: 2004

Language

• English

Media Info

• Pagination: 21p
• Serial:
  • PROCEEDINGS OF THE 22ND PIARC WORLD ROAD CONGRESS,19-25 OCTOBER 2003, DURBAN, SOUTH AFRICA - C12 TECHNICAL COMMITTEE ON EARTHWORKS, DRAINAGE AND SUBGRADE

Subject/Index Terms

• TRT Terms: Base course (Pavements); Conferences; Costs; Economics; Life cycle analysis; Local materials; Low volume roads; Pavements
• ITRD Terms: 4577: Aggregate; 2267: Attitude (psychol); 4563: By product; 8525: Conference; 224: Cost; 255: Economics; 9020: Evaluation (assessment); 5950: Life cycle; 2986: Low cost road; 2774: Low traffic road; 233: Natural resources; 2955: Pavement; 3055: Pavement design; 9063: Quality; 3665: Road construction; 2961: Roadbase; 328: Rural area
• Subject Areas: Economics; Finance; Highways; Materials; Pavements; I20: Design and Planning of Transport Infrastructure; I30: Materials;

Filing Info

• Accession Number: 01084066
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Jan 7 2008 3:09PM