Authors:
Taisir Khedaywi; Nabil Al Kofahi;
Abstract:
Stripping is the separation of the asphalt binder film from the aggregate surface due to the action of water. It
results from many factors, but moisture or vapor moisture is considered the major reason. Many methods are
used to predict stripping and effectiveness of anti-stripping agents. This study was a part of a comprehensive
study, which was conducted to solve asphalt road deteriorations in Jordan and conserve natural resources and budgets of road construction and maintenance. To achieve this objective, three types of aggregate (the most used in Jordan) were used: crushed limestone, uncrushed valley gravel and crushed basalt. Asphalt binder of (60/70) penetration and two anti-stripping additives: hydrated lime and a liquid additive (polyamine) were used as well. ASTM (D 3625), Texas boiling test, modified Texas boiling test by stirring and rolling bottle test were run on loose mixtures. Test results have shown that limestone is superior to valley gravel and basalt aggregates.
Moreover, lime additive (1.5-2% by weight of aggregate) is better than polyamine (0.75-1% by weight of AC). It was also revealed that aggregate type was the most significant variable affecting stripping. Anti-stripping agents are recommended to be used by the Ministry of Public Works and Housing where stripping potential is high.
Keywords:
Asphalt, Stripping, Additives, Boiling test, Rolling bottle test, Visual assessment