• International Journal of Highway Engineering
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• v.19 no.5
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• pp.131-141
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• 2017

PURPOSES : The main distress of asphalt pavements in monsoon climate regions are caused by water damage and plastic deformation due to repeated rain season and increased heavy vehicle traffic volume. In this study, the mechanical properties of polymer-modified warm mix asphalt (PWMA) materials are evaluated to use in monsoon climate regions such as Indonesia. METHODS : Comprehensive laboratory tests are conducted to evaluate moisture resistance and permanent deformation resistance for three different asphalt mixtures such as the Indonesian conventional hot-mix asphalt (HMA) mixture, the polymer-modified asphalt mixture, and the polymer-modified warm mix asphalt (PWMA) mixture. Dynamic immersion test and indirect tensile strength ratio test are performed to evaluate moisture resistance. The wheel tracking test is performed to evaluate rutting resistance. Additionally, the Hamburg wheel tracking test is performed to evaluate rutting and moisture resistances simultaneously. RESULTS :The dynamic immersion test results indicate that the PWMA mixture shows the highest resistance to moisture. The indirect tensile strength ratio test indicates that TSR values of PWMA mixture, Indonesian PMA mixture, and Indonesian HMA mixture show 87.2%, 84.1%, and 67.9%, respectively. The wheel tracking test results indicate that the PWMA mixture is found to be more resistant to plastic deformation than the Indonesian PMA. The dynamic stability values are 2,739 times/mm and 3,150 times/mm, respectively. Moreover, the Hamburg wheel tracking test results indicate that PWMA mixture is more resistant to plastic deformation than Indonesian PMA and HMA mixtures. CONCLUSIONS :Based on limited laboratory test results, it is concluded that rutting resistance and moisture susceptibility of the PWMA mixture is superior to Indonesian HMA and Indonesian PMA mixtures. It is postulated that PWMA mixture would be suitable for climate and traffic conditions in Indonesia.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.243-248
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• 2008

Moisture damage of asphalt pavements can usually occur because of the loss of adhesion and cohesion between the asphalt binder and aggregate in the asphalt mixture due to presence of water. And this is one of the causes that is effect on the main distress of asphalt pavement. The objective of this study is to find out moisture damage characteristics of asphalt pavement. Effects of this study changes of the material properties and resistance characteristics of moisture damage on the asphalt mixtures under various temperatures and repeated immersion using indirect tensile test and modify Lottman test were evaluated during this study. The asphalt mixtures were produced using straight asphalt binder, SBS modified asphalt binder and aggregates. The material properties (resilient modulus, indirect tensile strength, failure energy and $DCSE_f$) of the asphalt mixtures were generally decreased with increasing to moisture damage caused by the number of repeated immersion. The decrease ratios of material properties by repeated immersion on SBS modified asphalt mixtures were lower than those of straight asphalt mixtures at all three test temperatures. As a conclusion, current criterion for evaluation moisture damage of asphalt mixtures is difficult for using distinction standard because of the limited evaluation criterion with one time immersion and single material property. Based on this research, to evaluate long term moisture damage on asphalt mixtures, material property tests of various kinds with repeated immersion test are considered.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.113-116
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• 2007

This is a research for evaluated recycled glass powder to add asphalt concrete filler. To make a comparative study, Mechanical performance of lime stone and slag dust Mixtures was evaluated according to test procedure. Lab. performance tests included marshall stability, indirect tensile strength, resilient modulus and wheel tracking. Water resistance tests were evaluated by marshall strength ratio and tensile strength ratio. In conclusion, Results of mechanical performance showed that recycled glass powder mixtures were equivalent to conventional mixtures. Especially, result of tensile strength ratio tested recycled glass powder mixtures was superior to conventional mixtures.

• Journal of the Korean Geotechnical Society
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• v.23 no.11
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• pp.15-26
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• 2007

Los Angeles abrasion loss test has usally been applied to the quarry for the purpose of aggregate hardness estimation. 324 blocks from 25 sites of Kyeongsang basin samples of sedimentary rock were examined and tested in laboratary. This paper found that L. A. abrasion loss test is a good method to estimate engineering index such as uniaxial compressive strength, elastic modulus, indirect tensile strength, point load strength index, Schmidt hammer rebound value of sedimentary rocks with high correlation factor. Engineers will prefer L. A. abrasion loss test to the other one for design and construction as this method is quick and easy.

• Journal of the Korean Society of Hazard Mitigation
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• v.2 no.2 s.5
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• pp.61-72
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• 2002

The optimum fiber and asphalt binder contents were decided on the base of the Mashall mix design method. To compare the mechanical characteristics between the conventional(dense-graded 20) and the fiber-reinforced mixtures, indirect tension tests were conducted under three temperatures(5, 20, 60$^{\circ}C$). In particular, the wheel tracking tests were performed to evaluate the rutting resistances of the mixtures. Test results showed that the indirect tensile strength of fiber-reinforced asphalt concrete was higher than that of conventional one. The toughness of fiber-reinforced mixture was 1.27 to 1.97 times higher than that of conventional one, depending upon the temperature. In addition, the results of wheel tracking tests and the retained indirect splitting tension tests conducted at $60^{\circ}C$ revealed that the resistance to permanent deformation of fiber-reinforced mixture was stronger than that of the conventional one.

• Structural Engineering and Mechanics
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• v.90 no.5
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• pp.481-492
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• 2024

This research examined the mechanical behavior of fiber-reinforced concrete at unstable environmental conditions. Concrete composites with varying percentages of steel and glass fibers were analyzed. Compressive, indirect tensile, and fracture toughness properties were evaluated using the Edge Notched Disc Bend (ENDB) test under freezing-thawing and acidic environments and the results were compared with normal conditions. Steel fibers decreased the strength in the specified cycles, while glass fibers showed a normal strength trend. The compressive, tensile and fracture toughness of the samples containing 1.5 vol.% fibers showed a 1.28-, 2.13- and 4.5-fold enhancement compared to samples without fibers, after 300 freezing-thawing cycles, respectively.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.269-273
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• 1998

The failure of material structures or mechanical system is considered as a direct or indirect result of fatigue. In the design of mechanical structure for estimating of reliability, the prediction of failure life is the most important failure mode to be considered. However, because of a complicated behavior of fatigue in mechanical structure, the analysis of fatigue is in need of much researches on life prediction. This document presents a prediction of fatigue life of the SAPH45 steel, which is extensively for vehicle frame. The method using lethargy coefficient and stress distribution factor at pediction of fatigue life based on the consideration of the failure characteristics from the tensile test should be provided in this study.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.180-185
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• 1998

The study was conducted to evaluate the fundamental properties of waste tire asphalt concretes using polymer modified hinder that were made by dry process. The specimens of four types of polymer modified asphalt concretes were prepared, then Marshall test and indirect tensile strength tests were performed on these samples. The results showed that polymer modified waste tire rubber asphalt concrete was acceptable for the material of asphalt pavement surface layer.

• International Journal of Highway Engineering
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• v.12 no.2
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• pp.17-23
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• 2010

Since the relatively stiff binder shows a higher tensile strength as well as higher rutting resistance, it is believed that the binder stiffness is an important factor for rutting and tensile strength of asphalt mixtures. The typical tensile property is measured by indirect tensile strength (ITS) test at $25^{\circ}C$ and the rutting resistance is most widely measured by wheel tracking (WT) test at $60^{\circ}C$. The deformation strength ($S_D$) is newly developed property to estimate rut resistance of asphalt concretes at $60^{\circ}C$. The ITS and $S_D$ are very simple to measure by static test techniques, but the WT is measured by repeated loading procedure which requires relatively longer time and more efforts. Since these three properties are highly dependent upon the binder stiffness, it may be possible to estimate one property from another. Therefore, this study investigate the possibility of estimating the rutting characteristics (measured by WT test) by ITS or $S_D$ test, and the ITS by $S_D$. Because of binder stiffness effect, in the WT estimation by ITS, a tendency was observed for the higher ITS mixture to have the lower rut depth, giving $R^2{\fallingdotseq}$0.6, on the average. The ITS estimation by $S_D$ showed $R^2{\fallingdotseq}$0.64, and the WT estimation by SD showed $R^2{\fallingdotseq}$0.84, which is highest correlation among the three. Therefore, it was concluded that there is relatively good possibility of estimating WT result by $S_D$, and even though $R^2$ is somewhat low, there is some correlation between WT and ITS.

• Korean Chemical Engineering Research
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• v.55 no.3
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• pp.395-400
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• 2017

Coke strength was increased by adding ash-free coal (AFC) binder. In this study, the effect of the AFC binder on the physical and chemical properties of coke was experimentally investigated to understand the molecular mechanism for the improved coke strength. For reduced $CO_2$ emission in steelmaking industry, torrefied biomass fuel mixed with coal binder is also considered. The interface between the base coal and AFC was thus examined using Scanning Electron Microscope (SEM). The coke strength was commonly measured by performing the indirect tensile test and Nuclear Magnetic Resonance (NMR) spectroscopy in $^1H$ and $^{13}C$ modes. For comprehensive mechanism study of the enhanced coke strength thus obtained, ordinary coal for thermal power plant use was carbonized with AFC for subsequent SEM examination. The NMR spectroscopy results of coke samples positively revealed that the tensile strength was proportional to the average number of aromatic rings.