Evaluation of asphalt mix with dolomite aggregates for wearing layer

Abstract

Bearing capacity and durability of road pavement structure depends on design solution, transport loads, climate, materials and construction quality. But the main factors are selected materials for road pavement structure and their properties. Typically, there are selected high quality aggregates for asphalt wearing layer of heavy duty pavement. In Lithuania, granite aggregates are often used for asphalt wearing layer, but this magmatic rock is imported from other countries. Dolomite is one of the most available sedimentary rocks in Lithuania and quarries contain hundreds million tons of this material. Either, high quality dolomite is produced applying special extraction technology, and the mechanical properties of this material are similar to granite. The aim of this research is to evaluate high quality dolomite as aggregates for asphalt wearing layer and to design rut resistant asphalt mix with dolomite aggregates. Test results showed good bitumen-aggregate adhesion properties. There were designed asphalt concrete (AC) mixes using granite and high quality dolomite aggregates and stone mastic asphalt (SMA) mixes using high quality dolomite aggregates based on fundamental properties in accordance to standard EN 13108-1 and EN 13108-5. Resistance to permanent deformation of asphalt mixes is achieved by designing coarser gradation mixes with higher content of air voids (3–4%) comparing to traditional asphalt mixes for wearing layer (2–4%). Designed asphalt mixes were tested using empirical and performance based tests, which showed promising results for asphalt mixes with high quality dolomite aggregates.