Hydrated lime effect on moisture susceptibility of warm mix asphalt

Beneficial effects of using hydrated lime to reduce moisture susceptibility of Hot Mix Asphalts are well recognized and widely used in industry. In present study, the effect of varying percentages of hydrated lime (from 0% to 2%) on the moisture susceptibility of warm mix asphalt was evaluated. Based on the obtained results it was shown that increasing hydrated lime content reduces the moisture susceptibility of dense graded warm mix asphalt. However, 80% of tensile strength ratio was reached without utilization of hydrated lime in some prepared samples with gap grading, using polymer modified bitumen.

► Dense graded WMA mixes achieved the desirable TSR criterion with 2% hydrated lime.
► Gap graded mixes with 1% hydrated lime and Aspha-min passed the 80% criterion.
► WMA gap graded mixes made with Sasobit satisfied the criterion without any lime.
► TSR value of control mix decreased when more than 1.5% hydrated lime was added.
► Adding more than 1.5% lime to WMA gap graded mixes marginally increased the TSR.