PURPOSES : The objective of this study is to analyze the significance of binder aging in a hot-mix asphalt (HMA) mixture in an insulated camber for a long duration for repair works, where the absolute viscosity level and service life reduction (SLR) are assessed based on the haul time, as well as to suggest a methodology for reducing the aging level.
METHODS : Because the HMA mixture is stored in an insulated box carriage at high temperature for repair works, if the binder in the mix is severely oxidized, then the repaired pavement will not exhibit a long service life. Therefore, the 13-mm dense-graded HMA mix with PG64-22 was aged in an oven at 160 °C for 1, 2, 4 and 8 h to evaluate its aging level. Gel-permeation chromatography was performed on the mixture particle without binder recovery to measure the large-molecular size ratio, from which the estimated absolute viscosity (EAV) was computed using a best-fit regression model. The SLR values of aged and repaired mixes were estimated to determine the amount of deterioration in the mixes caused by severe aging. Hydrated lime (HL) was introduced into the mix at a ratio of 1.5 wt% of the total mix. The aging level and SLR were compared with those of the repaired mix without HL.
RESULTS : The binder EAV of the HMA mix increases significantly with the mixture aging duration. In particular, the binder EAV level of a 4-h aged mix is similar to the asphalt viscosity level of a pavement with approximately 7 years of service life. The service life expressed based on the aging level is interpreted as the reduced service life of the aged mix, which is already oxidized before it is used. Meanwhile, the binder of an 8-h aged mix without HL aged significantly and its SLR is approximately 11 years. However, its aging level and SLR reduced significantly when HL. is incorporated.
CONCLUSIONS : The binder aging level of the repaired mix increases significantly with its storage duration in a hot chamber for carriage. However, since the aging level decreases significantly by the incorporation of HL, the use of HL is highly recommended when preparing new mix for repair works to be performed in a hot-chamber for a long duration.

ABSTRACT
1. 서론
2. 재료 및 방법
    2.1. 사용 재료
    2.2. 시험 방법
3. 결과분석 및 고찰
    3.1. 노화 시간에 따른 Asphalt 특성변화
    3.2. 노화 억제
    3.3. 보수용 아스팔트 혼합물의 노화
4. 결론
REFERENCES

• 김영삼(강원대학교 지역건설공학과 박사수료) | Kim Yeongsam
• 김성운(강원대학교 석재복합건설신소재연구소 책임연구원) | Kim Sungun
• 이종섭(한국아스콘공업협동조합연합회 품질기술연구원 책임연구원) | Lee Jong-Sup Corresponding author
• 김광우(강원대학교 지역건설공학과 명예교수) | Kim Kwang W