Aggregate Gradation - Getting the Road Surface Right

Authors: Simon Fairbrother
Publication: New Zealand Journal of Forestry, Volume N.Z.J.For. 2010, Issue N.Z.J.For. 55(4) 2011, pp 11-12, Jan 2011
Publisher: New Zealand Institute of Forestry

Abstract: Construction of forest roads is an expensive undertaking. The road corridor needs to be located, the formation excavated and shaped, culverts placed, and aggregate spread and compacted to create a strong road surface. For many forest road engineers, this latter element is the most problematic. The winning or purchase of a suitable aggregate and transporting the material to the forest road site can cost over $60/m3, often representing 60-70% of the total cost of road construction. Forest managers faced with the need to control roading costs inevitably seek to reduce the cost of aggregate by substituting with lower-cost and/or locally available materials. However, when choosing lowcost aggregates for forest roads it is important that the right material is selected, or else money may be poorly spent.