SILANE PRETREATMENT OF MINERAL AGGREGATE TO PREVENT STRIPPING IN FLEXIBLE PAVEMENTS

Abstract

Debonding of asphalt from mineral aggregates (stripping) was termed a problem as far back as 1938, yet it continues to plague the paving industry today. Commercial antistrip additives are available, but their long-term effects are not well understood. A silane coupling agent was compared with a well-known commercially available liquid antistrip agent (amine) in the immersion-compression and double-punch debonding tests on two Arizona mineral aggregate sources. The silane was used as a mineral aggregate pretreatment, whereas the amine was added to the asphalt. The results of this research are encouraging and indicate that the silane generally performed as well as the liquid antistrip agent or better. Further testing is recommended along with construction of experimental projects to evaluate field performance.