• Journal of the Society of Disaster Information
• /
• v.7 no.1
• /
• pp.32-42
• /
• 2011

Many researches have been conducted to evaluate the performance of modified asphalt concrete mixtures. The research was conducted to estimate the laboratory mechanical characteristics of Elvaloy-modified asphalt concrete mixture. To achieve its intended objective, indirect tensile test and resilient modulus test were performed. The rest results revealed that indirect tensile strengths and resilient moduli of the Elvaloy-modified asphalt concrete mixture were higher than those of the conventional dense-graded. As a result, within the limits of the tests conducted in this research, it is predicted that the performance and stability of the Elvaloy-modified asphalt concrete mixture are better than that of the conventional dense-graded one.

• International Journal of Highway Engineering
• /
• v.7 no.4 s.26
• /
• pp.49-56
• /
• 2005

The effect of modified asphalts is evaluated by simple comparison of a single parameter (i.e., tensile strength, stiffness, etc.) between modified asphalt mixture and unmodified mixture. The use of a single parameter to evaluate the effect of modified asphalt must be questioned. Rather, a single unified framework that accounts for changes in key mixture properties is needed to effectively evaluate the modified asphalt mixtures. This study used a new performance-based fracture parameter as a single unified framework, the Energy Ratio (ER), for quantifying the effect of modified asphalts oil the fracture resistance of mixtures. The Energy Ratio was then used as a performance criterion for calculating the construction cost of two modified asphalt pavements (SBS and Crumb Rubber) and unmodified asphalt pavement. The results showed that the Energy Ratio of SBS modified asphalt was higher than those of crumb rubber and unmodified asphalt. Cost analyses indicated that the construction cost of the AC layer would be reduced by up to 24% by SBS modification. Based on the results, the Energy Ratio is capable of evaluating the effect of modified mixtures, and may form the basis of a promising fracture criterion for performance-based thickness design in asphalt pavements.

• Applied Chemistry for Engineering
• /
• v.5 no.3
• /
• pp.537-546
• /
• 1994

The physical characteristics of polymer modified asphalt depend on many parameters, such as, the polymer nature, polymer content and the asphalt properties. The objective of this study is to investigate the temperature susceptibility of polymer modified asphalt. The asphalts employed in this study were two different grades : a soft(200/300) grade and a hard(85/100) grade. And chlorinated polyethylene of two different characteristics were used : plastomer(Tyrin 2552) and elastomer(Tyrin CM0730). Temperature susceptibility of asphalt is a fundamental feature for characterizing asphalt and modified asphalt. It can be quantified by the penetration index(PI) and pen-vis number(PVN). These indices were obtained from the measurements of penetration and viscosity of the asphalt samples. For both of asphalts, the addition of the polymers increases the value of PI and PVN. Plastomer modified asphalt shows higher value of PI and PVN than elastomer modified asphalt. Soft grade shows more temperature susceptibility than hard grade at elevated temperatures.

• Polymer(Korea)
• /
• v.31 no.6
• /
• pp.538-542
• /
• 2007

This study is on the performance analysis of modified asphalts which were prepared by mixing the asphalt with polymer modifiers of varying compositions which were synthesized by the emulsion polymerization method. Thermal properties of mired asphalt were investigated by DSC (differential scanning calorimetry), and dispersion of modifiers in asphalt was investigated by the fluorescence microscope. Dynamic stability and permanent deformation velocities of mixed asphalt were investigated by wheel tracking measurements. Modifier 6 showed the best results in both penetration test and wheel tracking measurement among investigated modifiers, which supports MMA(methyl methacrylate) moiety in modifiers plays better contribution for the enhancement of asphalt performance than styrene moiety does.

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

• 한국방재학회:학술대회논문집
• /
• 2010.02a
• /
• pp.46.2-46.2
• /
• 2010

아스팔트 포장의 공용성능 행장을 위해 널리 사용되고 있는 폴리머 개질 아스팔트(PMA)는 높은 생산온도와 다짐온도로 인해 생산 시 연료 소비가 많고 시공관리가 어려운 단점을 가지고 있다. 이에 중온형 아스팔트 기술을 접목하여 고온에서의 아스팔트 점도를 낮춤으로써 이와 같은 문제점을 해결하고자 하였다. 바인더의 전반적 공용성능 향상을 위해서 폴리머 (SBR)와 작업성 개선을 위해 Wax 및 기타 첨가제를 혼합하여 아스팔트 바인더를 제조하였으며, 실험결과 PG 82-22의 높은 공용등급의 바인더를 얻었으며, 생산 및 시공온도는 기존의 PMA 아스팔트와 달리 일반 스트레이트아스팔트와 비슷한 수준을 확보하였다. 이를 이용한 아스팔트 혼합물의 공용 성능 면에서도 PMA개질 아스팔트와 비슷한 수준을 나타내었다.

• International Journal of Highway Engineering
• /
• v.9 no.4
• /
• pp.149-158
• /
• 2007

Evaluation of the asphalt mixture modified with crumb rubber modifier(CRM) was performed to estimate possibility of using it as a paying material. OACs(optimum asphalt content) of CRM modified asphalt mixtures by dry process and wet process were determined by Marshall mix design and Wheel tracking test and moisture susceptibility test by freezing and thawing were carried out with CRM modified asphalt mixtures at OACs. The results from these tests, resistance of permanent deformation of CRM modified asphalt mixtures were superior to one of AP-5 while showing very low resistance of moisture sensitivity by freezing and thawing. This means that CRM modified asphalt mixtures are very sensitive to freezing and thawing. However, CRM modified asphalt mixture with anti-stripping material showed high improvement to resistance of moisture susceptibility by freezing and thawing. Therefore, it is recommended that when CRM mixtures were used in domestic, CRM modified asphalt mixtures should be with prevention against freezing and thawing resistance by moisture susceptibility.

• International Journal of Highway Engineering
• /
• v.12 no.2
• /
• pp.81-90
• /
• 2010

This paper describes the results of laboratory and field performance tests on the polymer modified asphalt binder and mixtures developed in this study for porous asphalt pavements. Various physical and mechanical laboratory tests including DSR and BBR tests are performed for two types of modified binders, and one type of binder is selected based on the binder testing results. Mix designs are conducted for the selected asphalt binder and a Japanese modified binder, respectively. Various performance tests including fatigue tests, wheel tracking tests, and moisture susceptibility tests are conducted for the domestic and Japanese porous asphalt mixtures. Test results indicate that the overall performance characteristics of the domestic mixture are similar to or better than those of the Japanese mixture. Based on the laboratory testing results, the domestic porous mixture is applied to a field test section. Periodic field investigations are conducted to evaluate the changes in noise level and air voids with time. The road noise analysis shows that the noise levels of the porous pavement keep increasing and, after two years, are similar to those of SMA pavements.

• International Journal of Highway Engineering
• /
• v.12 no.4
• /
• pp.87-92
• /
• 2010

This study evaluates the laboratory properties of asphalt binder and mixture modified with R-EPDM(Recycling Ethylene Propylene Dien Monometer), which consists of R-EPDM as a main ingredient that is an industrial by-product made by manufacturing waste EPDM below 50 mesh as an additive. Superpave system was used to determine the PG(Performane Grade) and evaluate the property of R-EPDM modified binder. OACs(Optimum Asphalt Contents) of R-EPDM modified asphalt mixtures were determined by Superpave mix design using gyratory compactor and wheel tracking test and moisture susceptibility test were carried out with R-EPDM modified asphalt mixtures at OACs. The results from these tests, rutting-resistance and freezing and thawing resistance by moisture susceptibility of R-EPDM modified asphalt mixtures were superior to one of general asphalt mixtures(AP-5).

• International Journal of Highway Engineering
• /
• v.10 no.3
• /
• pp.239-246
• /
• 2008

In this study, the influence of reaction temperatures, mixing time and flexible modifier for crumb rubber modified asphalt(CRMA) as processing conditions were investigated. The temperature susceptibility and adhesion properties of neat and modified asphalts at low temperature measured using the penetration and tensile adhesion test. It was found that processing temperatures and flexible modifier were important factors for tensile adhesion strength and toughness energy at low temperature. The CRMA in the higher processing temperature and flexible modifier exhibited improved tensile adhesion properties which indicated the flexible structure of neat and modified asphalt binder. In general, the improvements of the physical properties in the CRMAs were due to the improvements of miscibility between CR and asphalt binder. It was found that the adhesion properties of the flexible agent modified CRMA were higher than CRMA were related to the flexible agent tend to penetrate into CR particles and asphalt binder.