Properties of recycled asphalt

The cost of flexible pavement construction, rehabilitation and maintenance is largely determined by the cost of the aggregate and binder (bitumen or asphalt cement) components. The soaring cost of petroleum products since the early nineteen sixties has made the bitumen contribution to the cost disproportionately large. Tanzania being one of the countries which do not produce petroleum, spends about 81 per cent of its foregn exchange (1989/90 budget) on purchase of petroleum products. The cost of production of aggregates in Tanzania is also very high. Under these circumstances recycling of bituminous materials on existing road and airport pavements, most of which need major rehabilitation, will save the country a lot of foreign exchange. The aim of the research therefore is to investigate the possibility of recycling bituminous materials, based on assessment of three major mechanical properties: the elastic stiffness, resistance to permanent deformation (creep) and fatigue [continued]…