Conference on highway engineering in Africa Addis Ababa April 1974: Paper C the design and construction of bituminous road surfacings

Abstract

When traffic on earth or gravel roads increases to a certain level it becomes necessary to provide a surface with lower maintenance and vehicle operating costs and without the dust nuisance in dry weather. In the majority of cases the most appropriate form in Africa is provided by a bituminous surfacing, particularly since this allows a stage construction process of economical road improvements to be adopted.For the first stage a cheap process, a single or double surface dressing (spray and chip treatment) prevents flying dust and surface attrition.The road is'sealed against ingress of rain thus maintaining the road structure in a stronger condition with resultant reduction of need for maintenance.The design and technique of construction of surface dressings for African conditions is discussed in the light of experience in Africa, Europe and Australia.