This paper was presented at the session titled `Innovative pavement design and evaluation techniques'. Construction of forestry roads on sites with clayey soils has been a problem for many years in north-western Quebec and north-eastern Ontario. Because of a lack of granular materials for use in road construction, most companies working in these regions must haul their wood in winter, when the roads are frozen. To be able to supply their mills with fresh fiber throughout the year, they are seeking new methods for improving their network of summer roads. Lime has been used to stabilise clays for many years in civil engineering projects throughout the world, and this report evaluates its potential for use in forestry. Lime acts as a hydraulic binding agent, and both binds clay particles together and absorbs water. After a period of "maturation", this reaction increases the soil's shear strength, increases its bearing capacity, reduces its susceptibility to swelling and shrinking, reduces its moisture content, and improves its workability and compaction capabilities. In lab tests, FERIC found that a CBR (California Bearing Ratio) of 56 could be reached by adding only 3% lime by weight to the soil. Preliminary in situ results have also shown potential, with an average CBR of 20 achieved using the same 3% lime application. (A)
Abstract