• Title/Summary/Keyword: Recycled Asphalt Mixture

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Evaluation of Warm-Recycled Asphalt Mixtures using Polyethylene Wax-Based Additive (중온화 첨가제를 사용한 중온 재생 아스팔트 혼합물 평가)

  • Lee, Jin Wook;Lee, Moon Sup;Kim, Yong Joo;Cho, Dong Woo;Kwon, Soo Ahn
    • International Journal of Highway Engineering
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    • v.15 no.4
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    • pp.43-51
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    • 2013
  • PURPOSES : The main purposes of this study are to examine the influences of polyethylene wax-based WMA additive on the optimum asphalt content of warm-recycled asphalt mixture based on the Marshall mix design and to evaluate performance of warm-recycled asphalt mixture containing 30% RAP with polyethylene wax-based WMA additive. METHODS: Physical and rheological properties of the residual asphalt were evaluated in terms of penetration, softening point, ductility and performance grade (PG) in order to examine the effects of polyethylene wax-based WMA additive on the residual asphalt. Also, To evaluate performance characteristics of the warm-recycled asphalt mixtures using polyethylene wax-based WMA additive along with a control hot-recycled asphalt mixture, indirect tensile strength test, modified Lottman test, dynamic immersion test, wheel tracking test and dynamic modulus test were conduced in the laboratory. RESULTS : Based on the limited laboratory test results, polyethylene wax-based WMA additive is effective to decrease mixing and compacting temperatures without compromising the volumetric characteristics of warm-recycled asphalt mixtures compared to hot-recycled asphalt mixture. Also, it doesn't affect the optimum asphalt content on recycled-asphalt mixture. All performance test results show that the performance of warm-recycled asphalt mixture using polyethylene wax-based WMA additive is similar to that of a control hot-recycled asphalt mixture. CONCLUSIONS: Overall, the performance of warm-recycled asphalt mixture using polyethylene wax-based WMA additive is comparable to hot-recycled asphalt mixture.

Evaluation of the Properties of a Hot In-Placement Recycled Asphalt Mixture as an Adding Mixer (믹싱기 추가에 따른 현장가열 재생 아스팔트 혼합물의 물성평가)

  • Lee, Kanghun;Park, Jaeyoung;Lee, Hwasun;Kim, Yongjoo;Lee, Jaejun
    • International Journal of Highway Engineering
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    • v.20 no.1
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    • pp.97-105
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    • 2018
  • PURPOSES : Asphalt concrete pavement is damaged by various causes such as traffic and environmental loads. The distressed pavement should be maintained by various methods to provide a comfortable and safe pavement for the driver. This study evaluates the effect of adding a mixing procedure to enhance the mixture quality in the hot in-placement recycled asphalt pavement method, which is an asphalt-pavement maintenance method. METHODS : Various test methods such as Marshall stability and dynamic stability, were employed to estimate the recycled asphalt mixture with and without an additional mixing, using the hot in-placement recycled asphalt pavement method. RESULTS : The mixture samples used in this study were taken before and after the addition of the mixer in the hot in-placement recycled asphalt pavement method (HIR) at field construction sites in GongJu and JinJu in South Korea. The test results of both mixtures satisfied the asphalt-mixture standard specifications. CONCLUSIONS : This study confirmed that adding a mixer in the HIR method results in a well-mixed new asphalt mixture, rejuvenator, and reclaimed asphalt mixture.

Properties of Cold Recycled Asphalt Mixtures with Alkali-activated Filler according to Wasted Asphalt Aggregate Content (폐아스콘 순환골재 혼입율에 따른 알칼리활성화 채움재 상온 재생 아스팔트 혼합물의 특성)

  • Lee, Min-Hi;Kang, Suk-Pyo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.6 no.3
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    • pp.199-206
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    • 2018
  • Due to the advantages of less raw materials and fossil fuel consumption, lower carbon footprint, and the capability of pavement performance improvement, the recycling technology of asphalt is developed and applied for road rehabilitation and construction in the western countries over the past two decades. Cold recycled asphalt mixtures are bituminous materials normally made by mixing recycled aggregate from wasted asphalt with an asphalt emulsion and water at room temperature. This paper aims at investigating the properties of cold recycled asphalt mixture with alkali-activated filler according to wasted asphalt aggregate content. As a result, as the content of wasted asphalt aggregate increased, the marshall stability of cold recycled asphalt mixture decreased and void ratio increased. Also, grading curves for cold recycled asphalt mixture as specified in GR criteria were satisfied in all aggregate mixing conditions regardless of the wasted asphalt aggregate content.

A Study on the Physical Properties of Recycled Asphalt Mixtures Using Glass Fiber Reinforcement (유리섬유 보강재를 이용한 재활용 아스팔트 혼합물의 물리적 특성에 관한 연구)

  • Park, Ki Soo;Yoo, Pyeong Jun
    • International Journal of Highway Engineering
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    • v.20 no.4
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    • pp.27-34
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    • 2018
  • PURPOSES : The objective of this study is to evaluate the physical properties of recycled asphalt mixtures reinforced with glass fiber. METHODS : Firstly, mixing design was conducted on recycled asphalt mixture for use of 50% recycled aggregate. Various laboratory tests were performed on four types of recycled asphalt mixtures with different glass fiber content to evaluate the physical properties. The laboratory tests include indirect tensile strength test, dynamic modulus test, Hamburg wheel tracking test and tensile-strength ratio to evaluate cracks, rutting and moisture resistance of mixtures. RESULTS : The indirect tensile strength of fiber reinforced glass increased about 139.4%. As a result of comparing the master curves obtained by the dynamic modulus test, the elasticity was low in the low temperature region and high in the high temperature region when the glass fiber was reinforced. The glass fiber contents of PEGS 0.3%, Micro PPGF 0.1% and Macro PPGF 0.3% showed the highest moisture resistance and rutting resistance. CONCLUSIONS : The test results show that use of glass fiber reinforcement can increase the resistance to cracking, rutting, and moisture damage of asphalt mixtures. It is also necessary to validate the long-term performance of recycled asphalt mixtures with glass fiber using full scale pavement testing and field trial construction.

Performance Evaluation of Cold-Recycling Asphalt Mixtures with an Inorganic Additive (무기질 첨가제를 사용한 상온 재활용 아스팔트 혼합물의 공용성 평가)

  • Kim, kyungsoo;Kim, HyunKyum;Kim, WonJae;Park, ChangKyu;Lee, HyunJong
    • International Journal of Highway Engineering
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    • v.20 no.1
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    • pp.27-33
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    • 2018
  • PURPOSES : The purpose of this study is to estimate the optimum content of an inorganic additive for cold-recycled asphalt mixtures and evaluate its performance. METHODS : An indirect tensile test, a tensile-strength ratio test, and an indirect tensile-fatigue test were conducted on cold-recycling asphalt mixtures with various additives. RESULTS : The laboratory performance tests indicated that granulated blast-furnace slag mixed with inorganic and cement activators provided optimum performance. The performance results of the cold-recycled asphalt pavement were similar to the inorganic and cement activators' performance in terms of the indirect tensile strength, tensile strength ratio, and indirect tensile-fatigue test. CONCLUSIONS : Overall, the performance of a cold-recycled asphalt mixture using inorganic additives and emulsion asphalt was comparable to a warm-recycled asphalt mixture. However, more experiments aimed at improving its performance and studying the effect of the inorganic additives must be conducted.

Study of the Curing Time of Cementless Cold Central Plant Recycled Asphalt Base-Layer through Field-Application Review (무시멘트 상온 재활용 아스팔트 기층의 현장 적용성을 통한 양생기간에 관한 연구)

  • Choi, Jun Seong;Jung, Chul Ho;Lee, Chan Hee;Lim, in su
    • International Journal of Highway Engineering
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    • v.19 no.2
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    • pp.67-74
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    • 2017
  • PURPOSES : The objective of this study is to ascertain the curing period of cementless cold central plant recycled asphalt base-layer, using mechanical analyses and specimen quality tests on the field. METHODS : Cold central plant recycled asphalt base-layer mixture was produced in the plant from reclaimed asphalt, natural aggregate, filler for the cold mix, and the modified emulsion AP using asphalt mix design and plant mix design. In order to examine the applicability of the curing period during the field test, the international standards for the possibility of core extraction and the degree of compaction and LFWD deflection were analyzed. Moreover, Marshall stability test, porosity test, and indirect tensile strength test were performed on the specimens of asphalt mix and plant mix design. RESULTS : The plant production process and compaction method of cementless cold central plant recycled asphalt base-layer were established, and the applicability of the optical moisture content for producing the mixture was verified through the field test. In addition, it was determined that the core extraction method of the conventional international curing standard was insufficient to ensure performance, and the LFWD test demonstrated that the deflection converges after a two-day curing. However, the back-calculation analysis reveals that a three-day curing is satisfactory, resulting in a general level of performance of dense asphalt base-layer. Moreover, from the result of the specimen quality test of the asphalt mix design and plant mix design according to the curing period, it was determined that the qualities satisfied both domestic and international standards, after a two-day curing. However, it was determined that the strength and stiffness after three-day curing are higher than those after a two-day curing by approximately 3.5 % and 20 %, respectively. CONCLUSIONS:A three-day curing period is proposed for the cementless cold central plant recycled asphalt base-layer; this curing period can be demonstrated to retain the modulus of asphalt-base layer in the field and ensure stable quality characteristics.

Performance Evaluation of Cold Recycled Asphalt Mixtures with Asphalt Emulsion and Inorganic Additives (무시멘트 첨가제를 활용한 상온 재활용 아스팔트 혼합물의 성능 분석)

  • Park, Chang Kyu;Kim, kyungsu;Kim, Won Jae;Lee, Hyun Jong
    • International Journal of Highway Engineering
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    • v.19 no.2
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    • pp.137-142
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    • 2017
  • PURPOSES :The objective of this study is to evaluate the performance of asphalt mixtures containing inorganic additive and a high content of reclaimed asphalt pavement (RAP). METHODS : The laboratory tests verified the superior laboratory performance of inorganic additive compared to cement, in cold recycled asphalt mixtures. To investigate the moisture susceptibility of the specimens, tensile strength ratio (TSR) tests were performed. In addition, dynamic modulus test was conducted to evaluate the performance of cold recycled asphalt mixture. RESULTS :It was determined that NaOH solution mixed with $Na_2SiO_3$ in the ratio 75:10 provides optimum performance. Compared to Type B and C counterparts, Type A mixtures consisting of an inorganic additive performed better in the Indirect tensile strength test, tensile strength ratio test, and dynamic modulus test. CONCLUSIONS : The use of inorganic additive enhances the indirect strength and dynamic modulus performance of the asphalt mixture. However, additional experiments are to be conducted to improve the reliability of the result with respect to the effect of inorganic additive.

Characteristics of Fatigue Resistance of Recycled Asphalt Concretes by Modified Mixing Process (재생 아스팔트 콘크리트 혼합물의 혼합방법 개선에 따른 피로저항 특성)

  • Doh, Young-Soo;Ko, Tae-Young;Kim, Kwang-Woo
    • International Journal of Highway Engineering
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    • v.8 no.4 s.30
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    • pp.135-143
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    • 2006
  • This study evaluated the fatigue resistance characteristics of hot-mix recycled asphalt mixtures which were prepared by a new blending method. Since the binder of RAP shows higher viscosity without being rejuvenated in the ordinary recycled mixture, this new(modified) blending method was developed for obtaining more uniform level of binder viscosity in the recycled mixture. Cold-planned RAP was collected and mix design was performed using 15% RAP content for two virgin aggregate, gneiss and granite. Penetration grade of 60-80 asphalt was used in mixing recycled mixture together with a polymer modifier, LDPE. Indirect tensile fatigue tests were carried out to evaluate characteristics of fatigue resistance of performance of recycled asphalt mixtures. The recycled mixtures with LDPE 6% showed higher repeated loading fatigue life. Fatigue life ratio of new(N) mixing method mixtures was approximately 0.6-0.7 before aging and 0.8-1.0 after aging treatment of ordinary(O) mixing method mixture. This means the N mixture becomes stronger with aging process increase. If further aging is treated, N mixture may be showing stronger resistance than O mixture.

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A Study on the Field Application of Superior Recycled Pavement of the Waste Asphalt (고품질 재활용 아스팔트 혼합물의 현장적용성에 대한 연구)

  • Kim, Jiwon;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.2
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    • pp.67-73
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    • 2012
  • Asphalt pavement waste can be recycled by crushing and heating methods with additional virgin materials and additives. In this study, a new additive using Sasol wax and Polyolefin elastomer was used for improving the quality of the Superior recycled asphalt pavement(SRP). Additive was added into the recycled mixture by 1.5% and 3% of binder content in order to have PG 70-22 and PG 76-22. Both mixtures were tested by Marshall apparatus, indirect strength testing methods, toughness testing methods, moisture susceptibility testing methods and wheel tracking testing methods. Test results met the standards of KS F 2349 and GR F 4005. Through research, it was found that these special recycled mixtures could be applied for the surface and base course of heavy traffic roads or equivalents. About 13,000 tons of the recycled mixture has been applied on Seoul Olympic road to provide new road to Hangang park for Seoul citizens.

Fundamental Properties of Recycled Cold Asphalt Mixtures with Recycled Sludge and Recycled Glass Aggregate (순환 슬러지 및 순환 유리골재를 사용한 순환 상온아스팔트 혼합물의 기초특성)

  • Lee, Hoo-Seok;Kang, Suk-Pyo;Kang, Hye-Ju;Lee, Min-Hi
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.8 no.3
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    • pp.302-309
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    • 2020
  • This paper is a basic study for applying the dried recycled sludge of waste sludge generated in construction waste intermediate treatment facility and the crushed recycled glass aggregate of waste glass bottles that cannot be recycled to the recycled cold asphalt mixtures. This paper reviewed the characteristics of recycled cold asphalt mixtures using recycled sludge and recycled glass aggregate. As a result, as contents of recycled sludge and recycled glass aggregate increased, the Marshall stability, indirect tensile strength, and tensile strength ratio of the recycled cold asphalt mixtures decreased, but flow and void ratio of that increased.