• 한국도로학회지:도로
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• v.11 no.2
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• pp.26-33
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• 2009

본 특집기사는 미국 NCAT(National Center for Asphalt Technology)에서 실험한 보고서(Hurley 및 Prowell, Evaluation of Sasobit for Use in Warm Asphalt, 2005)를 정리한 것으로 아스팔트 중온포장에 대해 연구하는 사람들에게 어느 정도 도움을 주고자 일부 내용을 번역하였다. 특히, 골재와 바인더 믹싱 및 현장다짐시 온도를 낮추어 궁극적으로 $CO_2$를 저감하고자 하는 노력이 많은 아스팔트 포장관련 종사자 및 연구자들에 의해 활발히 수행되고 있다. 본 기사에서는 중온에서도 작업성을 원활하게 하기 위해 사용되는 많은 첨가제 중 Fischer-Tropsch 왁스인 Sasobit에 대해 살펴보고자 한다. 여기서 관심을 두고자 하는 점은 중온 아스팔트를 실제로 활용할 시 과연 일반 아스팔트 포장과 비교했을 때 어느 정도의 공용성(Performance)을 확보할 수 있느냐 하는 점이다. NCAT의 실내실험을 통해 알아낸 결과로는 진동다짐기를 이용하는 것이 보다 현실적이라는 것과 중온다짐에 따른 아스팔트의 동탄성 계수의 변화가 적다는 것이다. 또한 APA(Asphalt Pavement Analyzer)를 통해 소형변형의 가능성이 높지 않음을 알 수 있었으며, 중온 아스팔트를 사용함에 따른 일반적인 문제점인 수분민감성이 커지는 현상에 대해서 실험을 통해 검증한 결과, 박리방지제를 쓰는 것이 좋다는 결론을 얻었다. 전반적으로 Sasobit의 실내공용성 평가는 우수하다고 보고되고 있다.

• International Journal of Highway Engineering
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• v.15 no.5
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• pp.1-9
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• 2013

PURPOSES : This study is to develop a method to evaluate lubrication of asphalt binder using WMA additives and compare their lubrication effects on two types of WMA additives and three types of asphalt film thicknesses. METHODS : This study is based on laboratory experiments and rheological analysis of the experimental results. Testing materials are aggregate diskes, asphalt, and WMA additives. The main testing method is stress sweep test by using dynamic shear rheometer (DSR). RESULTS : Sasobit gives more lubrication effects on film thicknesses 0.2mm and under but LEADCAP does on film thicknesses over 0.3mm. CONCLUSIONS : LVE-Limit is a better parameter to discern the lubrication effects on the thin film asphalt thickness. Both Sasobit and LEADCAP WMA additives provide effective lubrication at the compaction temperature.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.111-120
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• 2010

This study evaluated strength properties of recycled asphalt concretes using warm-mix technology. Granite with maximum size of 13mm and penetration grade of 80-100 virgin binder were used for mixing in recycled mixtures. Mix design was performed using 20% and 30% RAP(coarse : fine= 6 : 4) contents. GPC, penetration, absolute viscosity and kinematic viscosity were measured for determining ratio of two warm-mix additives (Evotherm and Sasobit). Low-density polyethylene(LD) used as asphalt modifier for improving stiffness of recycled WMA mixtures in this study. Therefore, a total of 11 mixtures were prepared in this study; 8 warm-mix recycled mixtures(2 RAP contents${\times}$2 warm-mix additives${\times}$2 modifiers), 2 hot-mix recycled mixtures and 1 HMA virgin mixture(control). Deformation strength, indirect tensile strength, moisture sensitivity, permanent deformation by wheel tracking tests were measured out for evaluating fundamental properties of recycled asphalt concretes using warm-mix technology.

• International Journal of Highway Engineering
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• v.15 no.4
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• pp.11-20
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• 2013

PURPOSES : This study is to develop a method to evaluate the compaction effects of asphalt binders using WMA additives and compare their compaction effects on two types of WMA additives, two types of testing temperatures, and three types of asphalt film thicknesses. METHODS : This study is based on laboratory experiments and rheological analysis of the experimental results. Testing materials are aggregate disks, asphalt, and WMA additives. The main testing method is the stress sweep test by using dynamic shear rheometer (DSR). In addition, the testing parameters obtained from the stress sweep results to evaluate lubrication effects are complex modulus and LVE-Limit. RESULTS : At both the first compaction condition ($110^{\circ}C$, 0.3mm) and second compaction condition ($80^{\circ}C$, 0.2mm) assumed, LEADCAP showed better compaction effects than Sasobit. CONCLUSIONS : The temperature $30^{\circ}C$ lower than general compaction temperatures can provide a better sensitivity for the evaluation of compaction effects. If a testing temperature and film thickness are grouped for the proper compaction conditions in the testing results, the compaction performance of each WMA additive can be more clearly discriminated in the grouped testing results matched with the grouped conditions.