The deteriorating condition of paved-road networks, the need to upgrade gravel roads to bituminous standards, and the limited resources available are challenging highway administrators and managers indeveloping countries, as well as donor agencies, to find less costly solutions to establish efficient and integrated transport systems.Information on the behavior and performance of bituminous-surfaced road pavements with a base built from as-dug laterite has been obtained from several countries. Most of these roads, carrying a wide range of traffic from the lower end of low-volume roads to about 2, 400 veh/day/lane, have performed well for 10 or more years; in many cases, their useful life can be extended by simple resealings. Data analysis included long-term variation of pavement condition (e.G., Roughness and cracking) and deflection, influence of load and temperatureon deflection, correlation between benkelman beam and dynaflect deflections, lateritic gravel characteristics, and strength parameters.The conclusion is that laterite bases can perform as well as crushed-stone or stabilized laterites under a wide range of circumstances, at a cost of about 20 to 30% of these more expensive materials. Thekey factors in the performance of laterite bases appear to be a high degree of compaction, well-drained subgrade, and rigorous materialselection in the borrow pits for application in the road. Further research is needed for more precise definition of the relationships between laterite characteristics, traffic loading, environment, and pavement performance. This paper appears in transportation research record no. 1291, Fifth international conference on low-volume roads, may 19-23, 1991, raleigh, north carolina, volume 2.
Abstract