• International Journal of Highway Engineering
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• v.6 no.4 s.22
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• pp.65-73
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• 2004

Marshall stability and flow don't reflect mechanical property of asphalt mixtures and have little correlation with rutting-related performance. There is often rutting occurred on the asphalt pavement which was constructed using a mixture passing the specification for stability and flow. This study dealt with comparison of volumetric properties of mixtures from Marshall mix design and from Superpave mix design. This study used one binder, three aggregates and two gradations. The mixtures were manufactured by each mix design method. Result showed that OAC, VMA and VFA by Marshall mix design were higher than those by Superpave mix design. This is because Mashall mixture has the gradation prone to rutting and it should be further investigated whether or not the high OAC is direct cause of rutting in asphalt pavement.

• International Journal of Highway Engineering
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• v.18 no.2
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• pp.1-9
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• 2016

PURPOSES : The performance properties (indirect tensile strength, rutting resistance, and resilient modulus) of recycled aged CRM mixtures and their correlation with Superpave binder properties (viscosity, high failure temperature, $G^*sin{\delta}$, and stiffness) were investigated. METHODS: A series of Superpave binder tests was performed by using a rotational viscometer, DSR, and BBR to evaluate the performance properties. In addition, the CRM mixes were artificially aged through accelerated aging processes, and their properties were evaluated. The correlation between the properties of recycled aged CRM binders and the engineering properties of recycled aged CRM mixtures was experimentally determined. RESULTS : The rut depth values decreased and the ITS values increased with increasing high failure temperature. In general, the resilient modulus properties seemed to be poorly correlated with the high-temperature values, regardless of the aggregate source. CONCLUSIONS: The recycled aged CRM binders and mixtures can lead to satisfactory performance, and the properties of these binders are strongly correlated with the engineering properties of the mixtures.

• International Journal of Highway Engineering
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• v.6 no.4 s.22
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• pp.45-53
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• 2004

This study dealt with correlation analysis between deformation strength and rut resistance of asphalt concretes based on binder grade in Superpave specification with changing submerging time. Currently, Mashall mix design is known to have little correlation with rutting related performance. Therefore, some agencies started to use the Superpave method for asphalt mix design. But this method has a weak point in that it can not distinct mechanical property of the asphalt mixtures designed. For solution of these problem, this study used deformation strength, $S_D$, of Kim test which is a new approach under development for finding property which represents rut resistance characteristics of asphalt mixtures under static loading. This study used two aggregates from two regions and five PG asphalt binders. Final rut depth (DR) and dynamic stability (DS) from wheel tracking (WT) test were obtained. and $S_D$ value of the same mixture specimen which was made by gyratory compactor was obtained using loading head [4(1.0)]. Three submerging times 30min, 40min, 50min were used as a test variable at $60^{\circ}C$. Correlation analysis of DR and DS with $S_D$ were performed based on PG grade. It was found out that the $S_D$ has a high correlation with DR and DS of superpave mixtures. The highest $R^2$ was found from the $S_D$ values of 30min. submerged specimen.

• 한국도로학회지:도로
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• v.2 no.2
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• pp.51-64
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• 2000

• International Journal of Highway Engineering
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• v.14 no.5
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• pp.47-55
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• 2012

PURPOSES: SUPERPAVE binder grade tests including Multiple Stress Creep and Recovery(MSCR) test are applied to evaluate rheological properties of four polymer modified binders. METHODS: To evaluate grade of four modified binders, PG testing protocols, such as DSR, BBR and MSCR are employed. RESULTS: It is observed that MSCR test shows different performance grades especially on modified binders. Both DMP and EG binder show similar high temperature performance to SBS 5% modified binder. CONCLUSIONS: Binder Grading system in Korea need to be reviewed to properly reflect the performnace of modified binders. The binders modified with DMP and EG can be possible alternatives SBS 5% modified binder considering its performance and cost.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.135-147
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• 2007

Segregation in asphalt pavements occurs as a result of the non-uniform distribution of coarse and fine aggregates and causes premature distresses, such as cracking, raveling, and stripping. The effect of segregation on rutting, however, has not been clearly identified. Experimental and analytical work performed in this study indicates that rutting performance is affected by segregation of mixtures. However, the aggregate structure of mixtures appears to be a more critical factor that determines the rutting performance, rather than the level of segregation. Based on the field mixtures evaluated, an increase of coarse aggregate volume in an asphalt mixture is an important factor that results in good rutting performance. This effect holds true for mixtures with lower levels of air voids, but for mixtures with higher levels of air voids, the air voids effect becomes dominant, resulting in a reduction in rutting performance. An air void content of 10% appears to be a threshold that determines the rutting performance of Superpave mixtures. Once the air void content exceeds 10%, the rutting performance of Superpave mixtures decreases significantly, despite the coarse aggregate volume.

• International Journal of Highway Engineering
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• v.2 no.3
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• pp.129-144
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• 2000

This paper presents the characteristics of viscoelastic properties and fatigue performance of SBS modified asphalt mixtures depending on the aggregate gradation. Dynamic shear rheometer (DSR) and uniaxial tensile creep tests are performed to analyze the thermomechanical behavior of asphalt binders and mixtures, respectively. Uniaxial tensile fatigue tests for seven different asphalt mixtures are conducted to evaluate the effects of aggregate gradations and SBS modifier on the fatigue performance of the mixtures. DSR and uniaxial tensile creep tests results show that the SBS modified asphalt mixtures have better rutting resistance than the unmodified mixtures at high temperatures regardless of the aggregate gradations used. Fatigue factor $G^*sin\delta$ in Superpave binder specification may not be adequate for evaluating the fatigue Performance of asphalt mixtures. It is observed from uniaxial tensile fatigue tests that SBS modified asphalt mixtures compared to unmodified mixtures have ten times longer fatigue lives regardless of the aggregate gradations(dense, SMA, and Superpave gradations) used in the mixtures. The better fatigue performance of the SBS modified mixtures is observed even after long-term aging process. The effect of aggregate gradations on the fatigue performance is not as significant as the SBS modifier. The cellulose fiber added in the SMA mixture has negligible effects on the viscoelastic Properties and fatigue performance of the mixture, but is effective in reducing draindown. Although the SBS modified asphalt binder is used, it may be necessary to add the cellulose fiber into the SMA mixture to prevent the draindown.

• International Journal of Highway Engineering
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• v.3 no.2 s.8
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• pp.113-121
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• 2001

Among the currently available binder specifications, Superpave Performance Grade asphalt specification is regarded as a superior specification on its theoretical background as well as pavement performance relationship. Many difficulties are expected; however, for Superpave implementation in Korea because of heavy burden of equipment cost as well as lack of trained personnel in asphalt industry, which may too much barrier to overcome in Korean situation. As an effort to improve qualify of asphalt binder, recently, people discuss about a possibility of constituting a performance-based asphalt specification using rather easy-to-measure asphalt properties. The objective of this paper is to determine the possibility of constituting a performance-based asphalt specification using an empirical asphalt properties, such as penetration ring and ball softening point rather than using fundamental properties of asphalt. Nine straight asphalts, that covers entire straight asphalt from all Korean refineries, and eighteen modified asphalts that were modified from two modifiers were included in the study. An analysis was made through a comparison between empirical properties and Superpave PG criteria. This study concluded that it may possible to constitute a pseudo-Superpave-like specification using an empirical asphalt properties as a specification criteria. Therefore, more systematic research is needed to constitute the asphalt specification.

• 한국도로학회:학술대회논문집
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• 2002.10a
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• pp.75-80
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• 2002

• 한국도로학회지:도로
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• v.2 no.4 s.6
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• pp.37-49
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• 2000

이 보고서는 수퍼페이브의 개념으로 설계된 혼합물이 시방규정에 만족하기 위하여 꼭 필요한 혼합물의 생산, 포설 및 다짐에 대한 내용을 정리한 것이다. 이 보고서 단독으로는 큰 의미가 없으며, 기존의 일반적인 혼합물에 사용되었던 훌륭한 시공기술이 동시에 사용되어야한다. 수퍼페이브가 적용됨으로 해서 발생되는 혼합물의 가장 큰 변화는 굵은입도의 혼합물사용 및 보다 많은 양의 모난골재사용 그리고 개질아스팔트의 사용 등이다. 이러한 변화들은 약간의 시공순서의 수정을 필요로 하게 된다. 이 보고서는 이러한 것에 대한 몇 가지 제안을 포함하고 있다.