عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Stripping is one of the major distresses that occur in asphalt pavements. This will then results in complete pavement disintegration. Various studies have shown that moisture damage results in some 25% decrease in mix modulus and 60% increase in wheel tracking; plus 30% reduction in fatigue life of HMA mixes. Researchers have shown that hydrated lime, if used in the amount of 1 to 2%, is one of the most effective anti stripping additives in reducing moisture susceptibility of asphalt mixes.
This research aimed at studying stripping resistance of asphalt mixes containing various amounts of hydrated lime. The testing method and the testing temperature were the two key factors that were considered in the research. The aggregates, selected from a quarry in west of Tehran were of siliceous type and the binder was a 60-70 penetration grade from Isfahan Refinery. Mixes containing 0, 1, 1.5 and 2% hydrated lime were prepared and were compacted. The testing program consisted of performing boiling water (ASTM D-3625), indirect tensile (AASHTO T-283) and wheel tracking (AASHTO T-324) tests. In addition, Marshall Quotient (ASTM D-1559) of the various mix compositions was determined. The tests were performed at two temperatures of 40 and 60oC. The testing results were analyzed using MiniTab software. These, performed both at dry and saturated conditions, resulted in determination of the optimum amount of hydrated lime in mixes. In addition, it was shown that at increased temperatures moisture susceptibility of mixes were increased.