Development of High Performance Asphalt Concrete Using Nonconventional and Conventional Aggregates

Resumo

The study investigates use of dolomite sand waste as filler or/and sand material
plus BOF steel slag as fine and coarse aggregate for design of high performance asphalt
concrete. Both environmental and economic factors contribute to the growing need for the use
of these materials in asphalt concrete pavements. This is particularly important for Latvia,
where local crushed dolomite and sandstone does not fulfill the requirements for mineral
aggregate in high and medium intensity asphalt pavements roads.
Annually 100 to 200 thousand tons of steel slag aggregates are produced in Latvia.
However, it has not been used extensively in asphalt pavement despite of its high performance
characteristics. Dolomite sand waste, which is byproduct of crushed dolomite production, is
another widely available polydisperse by-product in Latvia. Its quantity has reached a million
of tons and is rapidly increasing. This huge quantity of technological waste needs to be
recycled with maximum efficiency.
Various combinations of steel slag, dolomite sand waste and conventional aggregates were
used to develop AC 11 asphalt concrete mixtures. The mix properties tests include resistance
to permanent deformations (wheel tracking test, dynamic creep test) and fatigue resistance.
Laboratory test results showed that asphalt concrete mixtures containing steel slag and local
limestone in coarse portion and dolomite sand waste in sand and filler portions had high
resistance to plastic deformations and good resistance to fatigue failure.