Influence of gradations on performance of emulsified asphalt cold recycled mixture produced using vertical vibration compaction method

In this study, the effects of virgin aggregate content, such as mineral filler, machine-made sand, and coarse aggregate, on the performance of emulsified asphalt cold recycled mixtures (ECRMs) produced using the vertical vibration compaction method (VVCM) are evaluated. The optimum virgin aggregate contents are proposed based on the results. The results show that with increasing mineral filler content (mass fraction <5%), the mechanical strength, rutting resistance and crack resistance of the ECRMs gradually increase, whereas the moisture sensitivity increases initially but gradually decreases, and 3% mineral filler demonstrates the optimum moisture sensitivity compared to reclaimed asphalt mixtures. Further, as machine-made sand content increases, the mechanical strength, rutting resistance, crack resistance and moisture sensitivity of the ECRMs increase initially and decrease gradually, and the aforementioned performance of the ECRMs reaches the peak values when 20% machine-made sand is added, compared to mixtures without the machine-made sand. The mechanical strength, rutting resistance, crack resistance and moisture sensitivity of the ECRMs initially increase and then gradually decrease with the addition of the coarse aggregate. When the coarse aggregate content is 10%–30%, the ECRMs show a good performance, compared to mixtures without the coarse aggregate. To effectively improve the engineering properties of the ECRMs, the proposed optimum content of the mineral filler, machine-made sand and coarse aggregate are 3%, 20% and 10–30%, respectively.