• Elastomers and Composites
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• v.44 no.1
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• pp.63-68
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• 2009

Recently, much attention has focused on the permanent deformation of roads in hot summer and cracks in cold winter, which are detrimental to safe driving. This leads to necessity of modification of asphalt to resist those deformation. In this study, a type of modified asphalt was prepared by addition of a photoinitiator which is activated by ultraviolet lay. The mechanical and rheololgical properties of photoinitiator-modified asphalt were examined using UTM and rheometer. Results showed that the modified asphalt was effected by ultraviolet and thus tensile strength and storage modulus increased, due to molecular attraction, with initiator content and irradiation dose. Thermal analysis showed less weight loss upon photoinitiator-modification and this indicated that the molecular attraction is the result of cross linking reaction between asphalt molecules induced by photoinitiator. According to long term ultraviolet curing test, properties of the photoinitiator-modified asphalt did not decrease or even increase for 20 years. This indicates that useful life of the asphalt could be extended by addition of photoinitiator.

• International Journal of Highway Engineering
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• v.10 no.2
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• pp.205-219
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• 2008

The polymers, low-density polyethylene (LDPE) and styrene-butadiene-styrene(SBS) -modified asphalt mixtures are advanced asphalt pavement materials in which $3{\sim}6%$ of them, and/or some other additive, by weight of total binder are added. The purpose of modifying asphalt material is to improve typical weakness such as rutting and cracking resistance of normal asphalt mixtures. These materials have been proved to show many advantages and practical applicability in the plant and field. Wet processed PMA binder and/or dry processed asphalt mixtures are developed as field products for many years. The objective of this paper is to show the characteristics of the LDPE and SBS-modified asphalt mixtures by comprehensive evaluation and comparison with those of normal asphalt mixtures.

• Elastomers and Composites
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• v.43 no.2
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• pp.72-81
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• 2008

Nowadays, modifying asphalt to improve the resistancy of plastic deformation or rutting on roads has been drawing attention. In this study, asphalts were modified with modifying agents and ground rubber from waste tire (GRT), and the effects of modifier and GRT on the properties of asphalt were analyzed. The Marshall stability of modified asphalt was increased by 98% and the tensile strength increased by 43% compared to straight asphalt. GRT played an important role in enhancing these properties. Viscosity tests, penetration tests and TMA analysis showed the deformation resistancy of modified asphalt. IR and GPC tests indicated that asphalt and modifier have similar chemical structures to each other, and chemical bonding between asphalt and modifier have occurred so that the molecular size lengthened.

• International Journal of Highway Engineering
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• v.1 no.1
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• pp.85-96
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• 1999

This study was performed to evaluate performance of polymer-modified asphalt mixtures and specially designed reinforcement techniques against reflection cracking of the asphalt pavement overlay. Selected polymers were used for asphalt modification and polyester fiber, a polypropylene film (vinyl) and a grid were used for mixture reinforcement. Using the asphalt mixture with optimum asphalt content, a slab was made and cut into two pieces of specimen. A layer of grid or vinyl was placed at the bottom of specimen to strengthen the pavement layer against crack. A repeated loading was applied to the asphalt mixture specimen which is Placed on a cement concrete with a pseudo-crack. Crack propagation under repeated loading was monitored and effectiveness of the devised crack retarding techniques was evaluated. From the test results. a significant retardation of mode I crack progress was monitored from some of the modified and reinforced asphalt mixtures.

• Elastomers and Composites
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• v.32 no.3
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• pp.166-172
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• 1997

The objective in this study was investigated temperature susceptibility and low temperature fracture of rubber modified asphalt. A chlorinated polyethylene elastomer, Tyrin CM0730, was added to 200/300 grade asphalt with 3.0 and 5.0wt% to improve campatibility. The elastomer modified asphalts were analyzed for temperature susceptibility relating to penetration index(PI) and penetration-viscosity number(PVN) as well as low temperature fracture relating to fracture energy $(G_{IC})$. These indices were obtained from the measurements of penetration, viscosity, failure load and modulus. The addition of small amounts of elastomer to the asphalt resulted in a significant increase of both the PI and PVN over an unmodified asphalt. Also, the fracture energy increased with the addition of elastomer to asphalt. These significant improvement at both the high and low temperature result in enhanced performance.

• International Journal of Highway Engineering
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• v.11 no.4
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• pp.153-160
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• 2009

Falling Weight Deflectometer (FWD) tests were performed to evaluate the structural capacity of glass fiber reinforced (GFR), polymer modified (PM), and unmodified asphalt pavement in Korea-LTPP (Long Term Pavement Performance) section. FWD tests showed that the tensile strains of GFR and PM asphalt pavements at the bottom of asphalt layer were 29% and 21% less than that of unmodified asphalt pavement. The structural capacity was then used as a performance criterion for calculating the cost effect of GFR and PM asphalt pavements. From the results, 5cm of asphalt layer thickness was reduced by applying GFR asphalt, and 3cm by applying PM asphalt. However, construction cost of PM and GFR asphalt pavement were increased due to the higher GFR and PM asphalt price. Life cycle cost analysis showed that the initial construction cost of GFR and PM asphalt pavement were higher but the management and user cost were less than those of unmodified asphalt pavement.

• Journal of the Korean Ceramic Society
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• v.27 no.7
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• pp.833-840
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• 1990

For the development of multi-functional materials which has water reducing power, air entraining power and waterproofing power as well as blending additive in cement mortar the coal ash was modified with asphalt-stearic acid or asphalt-boiled oil mixtures by mechanical treatment. And the physical properties of cement mortar blended with modified coal ashes were compared with those of the water-tightness-cement mortar and the ordinary-portland-cement mortar added with AE.water reducing agent. The mortar of coalash-blend-cement modified with asphalt-stearic mixture was increased acid about 20% in initial strengths and decreased about 20% in water absorption ratio than those of ordinary coalash-blend-cement. The mortar of coalash-blend-cement modified with asphalt-bolied oil mixture was similar to the cement mortar added with AE.water reducing agent in water reduction ratio, air entraining conents and the initial strengths, also was similar to the water-tightness-cement mortar in water absorption and water permeability ratios.

• Journal of the Korea Concrete Institute
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• v.17 no.3 s.87
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• pp.467-472
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• 2005

Asphalt emulsion is manufactured by the emulsification of asphalt, and is considered as an energy-saving, ecologically safe material because it does not need any heating processes with gas emission and fire hazard in its use. This study is concerned with evaluating the feasibility of the use of an asphalt emulsion as a poly-meric admixture. Asphalt-modified mortars using an experimentally manufactured asphalt emulsion were prepared with various polymer-cement ratios, and tested far the mechanical properties such as strengths and adhesion and the properties related to durability such as water absorption, permeation, carbonation and chloride ion penetration. As a result, the waterproofness, carbonation resistance and chloride ion penetration resistance of the asphalt-modified mortars were markedly improved with an increase in the polymer-cement ratio, but their compressive strength and adhesion to mortar substrates were reduced with increasing polymer-cement ratio. Therefore, it is recommended to control their polymer-cement ratio to be $10\%$ or lower in their practical applications. Further study to improve their compressive strength and adhesion is needed.

• 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.

• Elastomers and Composites
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• v.44 no.3
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• pp.282-289
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• 2009

The pressure-sensitive adhesive(PSA) tapes are widely used as floor-sealing material in Korean constructive industry. However, the general PSA tapes can not seal the apertures completely. This is one of main reasons to cause imperfect finishing. In order to solve the problems, the asphalts were modified by FKM powder and SBS in this study. The physical properties of modified asphalts were examined by measuring the softening point, viscosity, tensile strength and adhesion strength of FKM and SBS modified asphalt. The softening point of SBS modified asphalt was increased greatly due to the formation of network structure in asphalt. Also, the change of adhesion strength of SBS modified asphalt with temperature was not so great comparing to those of pure asphalt and FKM modified asphalt. The best results of pressure-sensitive adhesion could be obtained by the SBS(linear) modified asphalt containing 6 wt.% of linear type SBS.