Experimental demonstration of liquid antistrip in hot mix asphalt pavement.

PDFTech ReportTechnical Report 17- 07Antistrip additivesHot mix paving mixturesMaineUnited StatesMaine. Dept. of Transportation. Transportation Research DivisionMaine. Dept. of Transportation. Transportation Research DivisionUS Transportation CollectionIn 2010, the Maine Department of Transportation constructed two projects with the use of Liquid Antistrip.The intent of these projects is to determine if an anti-strip admixture will improve the pavementquality in Northern Maine as well as other areas.In recent years, the Department has noticed many areas, particularly in Northern Maine, experiencing lossof aggregate in the wheel paths on recently placed HMA. This project has been selected due to its closeproximity to other previously constructed projects that have exhibited premature failure and durabilityissues, most generally raveling and loss of aggregate from the wearing course. It has generally beenaccepted that the use of ant-strip additives was not a requirement when using virgin aggregate mixtures,but there is evidence from other State and Canadian Province studies that indicate that moisture damageand aggregate stripping incidence increases proportionally with the increase in recycled asphalt (RAP)percentages. This study is being conducted to determine which criteria determines liquid anti-strip use,and if anti-strips will be required.The occurrence of aggregate raveling and stripping is not isolated to Region 5, but is also evident in otherparts of the state. This indicates that the issue may be related to not only aggregate sources, but RAPquality and percentages.As previously stated, liquid anti-strip has been used extensively by our Canadian neighbors in NewBrunswick. Their aggregates are very similar in nature to those in Northern Maine as well as similarclimatic conditions. They have been using this admixture for approximately 10 years. Irving Oil, as wellas All States Asphalts, supply this material. Thus, material availability is not an issue. Anticipated addedcosts for this material to be incorporated in our Hot Mix Asphalt is estimated to be in the range of $1 to $2/HMA ton