EVALUATION OF SA-1 PROCESS FOR REDUCTION OF HYDROCARBON USAGE IN BITUMINOUS PAVEMENT CONSTRUCTION
The evaluation consisted of laboratory processing of SA-1 treated and untreated experimental mixtures at high and low temperatures. Four replicate samples of each of the four resultant categories of mixture were tested for pertinent mixture properties and the results compared. Mixture properties of core samples, representative of the SA-1 treated and the untreated portions of a short field test section, were determined to evaluate the possible beneficial effects of SA-1 treatment. The quantities and properties of asphalts recovered from these cores were also determined and compared. In addition, comparisons were made of field and laboratory, SA-1 treated and untreated aggregates by examination with a scanning electron microscope (SEM) and energy dispersive X-ray analyses (EDAX), foaming tests, and infrared analyses of methanol extracts. On the basis of these test results, the SA-1 process does not appear to have a significant beneficial effect on the mechanical properties of asphalt concrete mixtures. Also, the study could not substantiate the claim that the process allows both a reduction of the percentage of asphalt required and a lowering of the mixing temperature in the manufacture of a paving mixture. These results may be due in part to the difficulty in preparing mixtures at specified moisture conditions at elevated temperatures in the laboratory. In view of these results and a comparison of the effects of ACRA-500 and SA-1 treatment on the properties of a bituminous mixture, it would appear that SA-1 would best be classified as an anti-stripping agent, the effectiveness of which remains to be determined. Recommendations for construction of field projects suitable for experimental evaluation are included in this report. /Author/
- Sponsored by the Federal Highway Administration.
Washington, DC United States 20590
- Smith, R W
- Publication Date: 1977-9
- Pagination: 52 p.
- TRT Terms: Aggregates; Alternatives analysis; Antistrip additives; Asphalt concrete; Bituminous pavements; Electron microscopes; Evaluation; Hydrocarbons; Mix design; Temperature; Testing; X ray analysis
- Subject Areas: Geotechnology; Highways; Materials;
- Accession Number: 00172040
- Record Type: Publication
- Source Agency: Federal Highway Administration
- Report/Paper Numbers: FHWA-RD-77-126 Final Rpt., FCP 34G1-034
- Files: TRIS, USDOT
- Created Date: Mar 29 1978 12:00AM