Assessing the Impact of Aggregate Quality on Flexible Pavement Perfotmance

Abstract

The construction of cost-effective flexible road pavements is depend on appropriate design and using quality materials for pavement construction. Road Flexible pavements are intended to limit the stress created at the subgrade level by the traffic traveling on the pavement surface, so that the subgrade is not subject to significant deformations. At the same time, the pavement materials themselves should not deteriorate to such an extent as to affect the riding quality and functionality of the pavement. These goals must be achieved throughout a specific design period. Pavements do deteriorate, however, due to, several factors can affect the pavement performance. Among these factors quality of materials and its deviation from specification. The objective of this research is, to assess the effects of aggregate quality on pavement performance in Jimma zone; this was achieved by conducting laboratory tests which were started visiting quarry sites and pavement aggregate production sites, then samples was extracted and brought to Ethiopian Road Construction Corporation laboratory, where qualities of aggregates investigated and finally marshal mix design were taken place.There are two source of aggregates for wearing course and one source also for base course aggregate. Aggregates from both sources each have its own deficiency in size distribution (gradation), in some basic properties of an aggregate supposed to be and with sever temperature the hot mix asphaltnot strong enough to resist the upcoming traffic loads, and these problems leads to the pavement not perform with expected durability, skid resistance and fatigue resistance, impose their impact on pavement performance or durability of the pavement.

Keywords: - Absorption; Particle Shapes; Pavement Performance; Size Distribution; Strength.