A previous ADOT research project resulted in strong evidence that the use of organo-silane as an asphalt additive was very effective in preventing stripping in asphalt concrete pavements. A test section approximately 2800 ft long and 12 ft wide incorporating a silane agent, Dow Corning 990, was placed on the crossroad of the east Williams T.I. on SR 64 between MP 185.3 and 185.7 in October 1981 to verify that claim. Pave Bond Special (PBS) anti-strip agent was used on ehe remaining portion of the roadway. The PBS sections directly adjacent to the silane test section were designated as control sections. In January 1984, visual observations of the silane test section indicated that the pavement surface experienced slight raveling throughout the section and moderate to severe raveling at several localized areas. The PBS control section was in excellent condition. The experimental test section was overlayed by 1 in. ASCS in October 1984 which prevented further field evaluation. Laboratory tests were conducted on asphalt concrete samples obtained at the time of construction and on cores taken from the silane and PBS sections 5 months and 3 years after construction. The results showed that the PBS treated material has superior properties. However, several factors made the results questionable: difference in bulk densities between PBS and silane cores, clay material was observed in both mixtures and therefore increasing the moisture susceptibility, and long delays between the time the cores were drilled and the time they were tested. Because of the limited field evaluation and the limitations on the validity of the laboratory results, no major conclusions can be drawn regarding the effectiveness of the silane in preventing stripping.

Media Info

  • Pagination: 20 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00622379
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Report/Paper Numbers: FHWA/AZ8101
  • Contract Numbers: PL-1(31) Item 116
  • Created Date: May 31 1992 12:00AM