개립마찰포장용 아스팔트 혼합물의 소성변형 특성연구 = Rut characteristics of open-graded friction course (OGFC) asphalt mixtures

다국어 초록 (Multilingual Abstract)

The objective of this study was to evaluate rut resistance characteristics of open-graded friction course (OGFC) asphalt mixtures. Two maximum size aggregates (10 mm and 13 mm) with three polymer-modified asphalt mixtures were used to prepare OGFC asphalt mixtures for the strength against deformation (SD) and asphalt pavement analyser (APA) tests. Three polymers included LDPE (low-density polyethylene), CRM (crumb rubber modifier) and SBS (styrene-butadiene-styrene). Six OGFC mix specimens were prepared at optimum asphalt content with the air void ratio of 16.2~17.3% using gyratory compactor. The SD test results showed that LDPE mixes showed approximately 4.2 MPa on average, while CRM and SBS mixes showed 3.6 MPa and 2.7 MPa, on average, respectively. APA test results was similar to those of SD; rut depths of LDPE, CRM and SBS mixtures being 1.35 mm, 3.5 mm, and 4.2 mm, on average, respectively. Therefore, the OGFC mixes using LDPE was found to show strong rut resistance properties in both tests, although SD was slightly lower than 4.25 MPa, which is the minimum limit of 1st class highway dense-grade asphalt pavement in Korea. Since OGFC specimen has air void ratio of 16-17%, which is 4 times greater than dense-grade specimen, instead of applying the dense-grade property limit directly to OGFC, it is suggested to prepare reasonable limits for OGFC mixes in the future. The regression analysis between APA rut depth and SD showed that the two properties has relatively high correlation with R2 > 0.81. Therefore, it will be possible to use SD for estimation for OGFC rut resistance by SD after further studies.