Optimization of Local Aggregate Use in SMA

Stone-matrix Asphalt (SMA) has exhibited good comparative performance; but is relatively more expensive than standard dense-graded asphalt concrete mixtures. Because SMA relies on stone-on-stone contact of coarse aggregates, it uses high quality coarse aggregate. This may require long-distance hauling in some locations. Hence, if local marginal quality aggregates can be used in SMA, it will be cost efficient and would reduce hauling emissions. To maintain SMA performance, load-carrying aggregate skeleton should be intact when using local coarse aggregate and any breakage be controlled. SMA design, compacted at 50-gyration, were introduced to accommodate dolomite, crushed gravel, and limestone coarse aggregate. Possible aggregate degradation assessment will also be presented.