Laboratory evaluation of Sasobit and Aspha-Min Additives in Warm-Mix Asphalt
Document Type : Original Article
Authors
1 Department of Civil Engineering, Malard Branch, Islamic Azad University, Malard, Tehran, Iran
2 Department of Civil Engineering, Malard Branch, Islamic Azad University, Malard, Tehran, Iran.
Abstract
Warm-mix asphalt (WMA), which reduces the production temperatures
(mixing and compaction), while maintaining the advantages of hot-mix asphalt (HMA), is becoming an attractive paving material. In this study, rheological properties of two commonly used performance grade (PG) binders (PG 64-22 and PG 70-28) were evaluated, with and without Sasobit and Aspha-Min additives. For PG 64-22, 2%, 3%, and 4% Sasobit additive reduced the mixing temperature of the pure binder from 163°C to 147°C (i.e., by 16°C). In case of the PG 70-28, the reductions are 10°C, 12°C and 13°C, respectively, for 2%, 3%, and 4% Sasobit additive. No significant decrease in mixing temperature by the Aspha-Min additive was observed in using the rotational viscometer. Evaluation of the binders on the basis of G*/sin () demonstrates no negative effect on high-temperature grading due to
high-temperature viscosity reduction. With the addition of 4% Sasobit additive,
the high-temperature binder grading of PG 64 (actually PG 65) increases to PG 69, while 4% Sasobit additive improves the PG 70 (actually PG 75) to PG 80. No significant changes in grading were observed with the addition of the Aspha-Min additive. In fact, reduction in binder viscosity and improvement in binder grading with- out increasing the viscosity indicate
two-way reductions (both direct and indirect) in production temperatures by the Sasobit additive. Finally, the Sasobit additive is found to decrease the asphalt pavement analyzer rut depths significantly, and these rut depths correlate well with the rutting factor G*/sin(). It was also observed that rutting potential decreases with decreasing mixing and compaction temperatures. Comparatively, a smaller reduction in rut depths was observed by adding the Aspha-Min additive.
(mixing and compaction), while maintaining the advantages of hot-mix asphalt (HMA), is becoming an attractive paving material. In this study, rheological properties of two commonly used performance grade (PG) binders (PG 64-22 and PG 70-28) were evaluated, with and without Sasobit and Aspha-Min additives. For PG 64-22, 2%, 3%, and 4% Sasobit additive reduced the mixing temperature of the pure binder from 163°C to 147°C (i.e., by 16°C). In case of the PG 70-28, the reductions are 10°C, 12°C and 13°C, respectively, for 2%, 3%, and 4% Sasobit additive. No significant decrease in mixing temperature by the Aspha-Min additive was observed in using the rotational viscometer. Evaluation of the binders on the basis of G*/sin () demonstrates no negative effect on high-temperature grading due to
high-temperature viscosity reduction. With the addition of 4% Sasobit additive,
the high-temperature binder grading of PG 64 (actually PG 65) increases to PG 69, while 4% Sasobit additive improves the PG 70 (actually PG 75) to PG 80. No significant changes in grading were observed with the addition of the Aspha-Min additive. In fact, reduction in binder viscosity and improvement in binder grading with- out increasing the viscosity indicate
two-way reductions (both direct and indirect) in production temperatures by the Sasobit additive. Finally, the Sasobit additive is found to decrease the asphalt pavement analyzer rut depths significantly, and these rut depths correlate well with the rutting factor G*/sin(). It was also observed that rutting potential decreases with decreasing mixing and compaction temperatures. Comparatively, a smaller reduction in rut depths was observed by adding the Aspha-Min additive.
Keywords
-Adding a Synthetic Zeolite”, June, www.asphamin.com.
-Corrigan, M., (2005), “Warm Mix Asphalt Technologies and Research”, FHWA, May www.fhwa.dot.gov/pavement.
-Day, J. A., and P. Naidoo, (2004), “Warm Mix Asphalt in Overnight Airport Runway Paving and Emergency Pavement”, Presented at 41st Annual Meeting of the Petersen Asphalt Research Conference, Cheyenne, Wyo., and June, pp. 21–23.
-Hamid, W.B. Use of Raw Chatin, (2004), “Hot Mix Asphalt Employing Superpave Design Methodology, MS thesis, University of Oklahoma, Norman.
-Hurley, G. C., and B. D. Prowell, (2005), “Evaluation of Aspha-Min Zeolite for Use in Warm Mix Asphalt”, NCAT Report 05-04, National Center for Asphalt Technology, Auburn, Ala., June.
-Hurley, G. C., and B. D. Prowell, (2005), “Evaluation of Sasobit for Use in Warm Mix Asphalt”, NCAT Report 05-06, National Center for Asphalt Technology, Auburn, Ala., June.
-Roberts, F. L., P. S. Kandhal, and E. R. Brown, (1996), “Hot Mix Asphalt Materials, Mixture Design, and Construction”, 2nd ed., NAPA Research and Education Foundation, Lanham, Md.
-Sisko, A.W., and L.C.Brunstrum, (1969), “NCHRP Report 67: Relation of Asphalt Rheological Properties to Pavement Durability”, HRB, National Research Council, Washington, D.C.
-Stuart, K. D., and R. P. Izzo., (1995), “Correlation of Superpave G*/sin δ with Rutting Susceptibility from Laboratory Mixture Tests”, In Transportation Research Record 1492, TRB, National Research Council, Washington, D.C., pp. 176–183.
-Sherwood, J. A., N. L. Thomas, and X. Qi., (1998), “Correlation of Superpave G*/Sin δ with Rutting Test Results from Accelerated Loading Facility”, In Transportation Research Record 1630, TRB, National Research Council, Washington, D.C.,
pp.53-61.
pp.53-61.