Evaluation of the use of antistripping additives in asphaltic concrete mixtures.

PDFTech Report46Research Project No. 68-3B(B)Louisiana HPR 1 (7)Stripping (Pavements)Asphalt cementAntistrip additivesAsphalt mixturesLouisianaLouisiana. Dept. of HighwaysArena, Philip J.Ashby, J. T.Louisiana. Dept. of Transportation and DevelopmentUnited States. Federal Highway AdministrationUS Transportation Collectionstripping is not a major problem in Louisiana. However there has been isolated instances of stripping occurring within the state and this study was initiated to ascertain if antistripping additives would have any benefical effect in combating stripping.A preliminary laboratory investigation was conducted on seven different commercially avilable additives to select one for field use. Based solely on the laboratory tests, tedicote 80-S was selected for field use.A four mile test section was constructed on State Route La. 3092 in November, 1968. Approximately one mile of this project was constructed with the antistripping additive added to the asphalt cement in the amount of 0.5 percent by weight. the remainder of the project was used as a control section.Comparative tests were conducted on the asphaltic cement and hot mix with and without the additive to ascertain if the antistripping additive had any effect on the asphalt or hot mix.The results of these comparatives indicated that the additive had a negligible effect on the properties tested.In addition to the comparative tests conducted, the control and test sections were visually compared six months and one year after construction to ascertain if any raveling or pitting was occurring in either section.At the end of the allotted time for study, no raveling or pitting had occurred in either the test or control section. A slight textual difference did develop between the sections in the form of a more open texture in the control section.Based on this study alone, it is not possible to recommend the used of antistripping additives on a state-wide basis. However it is recommended that additional periodic visual checks be made on this project to ascertain if the slight textural difference that now exists between the test and control section develops into any indication of stripping. If any stripping should occur and the test section indicates that the antistripping additive has had a benefical effect, a supplemental report will be issued