• 한국건설순환자원학회논문집
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• 제6권2호
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• pp.112-118
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• 2011

환경에 관련된 인식이 급격하게 변화되는 현재의 흐름에 따라 도로포장부문에서 별다른 주목을 받지 못하던 재생아스팔트포장에 관한 실제 성능 및 적용성을 알아보고자 실내실험, 현장 시공 및 공용성능에 대한 추적조사를 실시하였습니다. 문헌고찰을 통하여 재생아스팔트포장의 현장적용에 대한 정보를 수집하였고 실제 생산현장과 접촉하여 시료를 획득하여 배합설계와 현장시공을 2차례에 걸쳐 실시하였습니다. 배합설계(실내실험)에서는 재생골재의 세립분 및 골재파쇄로 인해 배합설계에 시간소모가 많았으며 목표입도를 맞추는데 어려움이 있었으나, 공용성능 추적조사에서는 시험시공구간의 균열이 시공후 5-6년 이후에도 발견되지 않았고 기타 포장파손도 발견되지 않아 양호한 상태를 나타내고 있었습니다. 또한, DSR을 이용한 재생바인더에 대한 피로시험결과, 일반적으로 선택되고 있는 재생골재 투입비율 30%에서 바인더의 피로수명이 베이스 아스팔트에 비하여 약 30~40%정도 감소하는 것으로 나타났습니다. 결론적으로 재생아스팔트포장의 취약점으로 알려진 균열문제는 충분한 품질관리를 통하여 극복될 수 있으며 이 품질관리에는 적절한 바인더 선택이 매우 중요할 것으로 판단됩니다. 재생아스팔트포장은 일반아스팔트포장과 비교하여 품질에 큰 차이는 없으며 재생골재의 투입비율과 바인더 선택을 적절히 하는 경우에는 국가적으로 이산화탄소 발생 억제를 통한 환경보호와 비용절감을 동시에 이룰 수 있을 것으로 보입니다.

• 한국도로학회논문집
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• 제19권2호
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• pp.75-85
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• 2017

PURPOSES : The purpose of this study was to determine the optimum mix design of the content of 100 % reclaimed asphalt pavement (RAP) for spray injection application with different binder types. METHODS : Literature review revealed that spray injection method is the one of the efficient and economical methods for repairing a small defective area on an asphalt pavement. The Rapid-Setting Polymer modified asphalt mixtures using two types of rapid setting polymers-asphalt emulsion and a quick setting polymer asphalt emulsion-were subjected to the following tests to determine optimum mix designs and for performance comparison: 1) Marshall stability test, 2) Retained stability test, 3) Wet track abrasion test, and 4) Dynamic stability test. RESULTS and CONCLUSIONS : Type A, B, and C emulsions were tested with different mix designs using RAP aggregates, to compare the performances and determine the optimum mix design. Performance of mixtures with Type A emulsion exceeded that of mixtures with Type B and C emulsion in all aspects. In particular, Type A binder demonstrated the highest performance for WTAT at low temperature. It demonstrated the practicality of using Type A mixture during the cold season. Furthers studies are to be performed to verify the optimum mix design for machine application. Differences in optimum mix designs for machine application and lab application will be corrected through field tests.

• 한국도로학회논문집
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• 제18권2호
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• pp.61-71
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• 2016

PURPOSES: The objective of this study was to determine the optimum ratio of mix design, for a reclaimed asphalt pavement (RAP) content of 100%, for spray injection application. METHODS: A literature review revealed that spray injection is an efficient and cost-effective application for fixing small defective regions of an asphalt pavement. Rapid-setting polymer-modified asphalt mixtures prepared from two types of rapid-setting polymer asphalt emulsion were subjected to Marshall stability and wet track abrasion tests, in order to identify the optimum mix designs. RESULTS and CONCLUSIONS : Different mix designs of type A and type B emulsions were prepared using RAP and virgin aggregates, in order to compare the performance and determine the optimum mix design. The performance of mixtures prepared with RAP was superior to that of mixtures containing virgin aggregates. Moreover, for optimum ratio of the design, the binder content prepared from RAP was set to 1~2% lower than that consisting of virgin aggregates. Compared to their Type A counterparts, type B mixtures consisting of a reactive emulsion performed better in the Marshall stability and wet track abrasion tests. The initial results confirmed the advantages associated with using RAP for spray injection applications. Further studies will be performed to verify the difference in the optimum mix design and performance obtained in the lab-scale test and tests conducted at the job site by using the spray injection machine.

• 한국건설순환자원학회논문집
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• 제9권4호
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• pp.633-641
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• 2021

본 연구에서는 철강산업 부산물인 제강슬래그 및 폐아스팔트 콘크리트포장 파쇄물인 순환골재를 사용하여 아스팔트 혼합물용 천연골재를 대체 가능성을 파악하고 제강슬래그를 활용한 아스팔트 혼합물의 공용성 평가를 수행하였다. 일반 WC-2와 Slag WC-2(R)에 대한 평가는 동일한 조건으로 수행하였으며, 수행기관은 국가 공인시험기관(KTR) 및 한국도로학회로 각 기관의 연구용역을 통해 평가되었다. 동적안정도, 동탄성계수, 피로균열 시험결과 슬래그 아스팔트 혼합물이 일반 아스팔트 혼합물에 비해 각각 140%, 저온·고온 487·350%, Low·Middle·High Stress Level 32·325·900% 증가하는 것으로 조사되었다. 함부르크 휠 트래킹 시험결과 두 가지 혼합물의 수분저항성이 우수한 것으로 조사되었으나, 슬래그 아스팔트 혼합물 시험결과에 변곡점이 없고 변위발생량이 낮아 일반 혼합물 대비 우수한 것으로 조사되었다. 장기공용성 평가(APT) 결과 슬래그 아스팔트 혼합물에서 소성변형 발생량이 6.5% 적게 발생하였으며, 표층, 기층 및 하부층의 압축량을 분석한 결과 슬래그 포장도로의 표층 소성변형 저항성이 45% 높게 조사되었다.

• 한국도로학회논문집
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• 제20권1호
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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.

• International Journal of Concrete Structures and Materials
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• 제3권2호
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• pp.91-95
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• 2009

Reclaimed asphalt pavement (RAP) is abundant substitute for natural aggregate in many areas. It is obtained by crushing of old road pavements in milling machine during rehabilitation and reconstruction process. In this study, reclaimed asphalt pavement mortars (RAPM) have been produced with different cement dosages and replacement ratios. The destructive and nondestructive tests have been conducted on specimens to determine physical and mechanical properties of RAPM. The free and restrained shrinkage tests on RAPM have been conducted to predict fractural behavior of mortars. The aim of the shrinkage tests was to delay crack formation and improve strain capacity of mortars before cracking. The results showed that RAPM exhibits lower elasticity modulus; however the tensile capacity was improved for deformation before cracking.

• 한국건설순환자원학회지
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• 제12권3호
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• pp.33-38
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• 2017

• 대한토목학회논문집
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• 제38권2호
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• pp.311-317
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• 2018

아스팔트 콘크리트 포장의 예방적 유지보수방법 중 하나인 표면강화공법의 실내 성능 평가를 수행하였다. 표면강화공법과 아스팔트 콘크리트 포장과의 부착력 평가 결과 미끄럼방지 포장 및 교면방수재료 기준을 상회하는 부착성능을 나타내었다. 윤하중재하실험과 박리저항성, UV저항성 실험을 통해 교통 및 환경하중에 대해 충분한 내구성을 확보할 수 있는 것을 확인하였다. 표면강화공법은 내투수성과 내화학성이 뛰어나 포장내로 수분 침투를 막고 화학물질로부터 포장을 보호할 수 있으며, 노화된 아스팔트 바인더의 재생효과가 있어 재생 아스팔트 콘크리트에 적용하였을 때 재래식 가열 아스팔트 콘크리트 혼합물에 비하여 약 5%의 터프니스를 증가시켰다. 아스팔트 표면강화공법은 아스팔트 콘크리트 포장의 내구성을 향상시킬 수 있는 특성을 갖는 것으로 나타났다.

• 한국도로학회논문집
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• 제19권5호
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• pp.13-20
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• 2017

PURPOSES : This research was a laboratory study for evaluating the Reclaimed Asphalt Pavement (RAP) mixture added developed rejuvenator for warm mix recycling. Waste asphalt mixtures occupy about 18.2% of construction wastes in Korea. Moreover, most rejuvenators were imported from Europe or the U.S. Therefore, improving usage of RAP with a developed rejuvenator material provides environmental protection at a reduced cost. METHODS : The specimen used for this experiment was performed by only using RAP. A suitable rejuvenator for Target PG was then added. In addition, a conventional rejuvenator was selected to compare performance and specimens introduced with the same procedure as the developed rejuvenator was prepared. In order to evaluate rutting resistance and water susceptibility, we conducted a deformation strength test, a tensile strength ratio test, and a dynamic immersion test with the prepared mixtures. RESULTS :Laboratory test results indicated that both the developed additive and conventional additive improved performance of the recycled asphalt mixtures compared to mixtures without the rejuvenator. In addition, the deformation strength test and TSR test results satisfied standards for domestic recycling asphalt mixtures. The dynamic immersion test showed that the developed rejuvenator has superior scaling resistance than the conventional rejuvenator. CONCLUSIONS : In terms of rutting resistance and moisture susceptibility, the warm mix recycled asphalt mixtures with the developed rejuvenator appeared to effectively recovered performance.

• Advances in concrete construction
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• 제4권3호
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• pp.207-220
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• 2016

The objective of this study was to evaluate the influence of recycled materials, namely, shredded scrap tire (SST), reclaimed asphalt pavement (RAP) and class C fly ash (CFA) on compressive and tensile strength of concrete. Either SST or RAP was used as an aggregate replacement and class C fly ash (CFA) as Portland cement replacement for making concrete. A total of two types of SST and RAP, namely, chips and screenings were used for replacing coarse and fine aggregates, respectively. A total of 26 concrete mixes containing different replacement level of SST or RAP and CFA were designed. Using the mix designs, cylindrical specimens of concrete were prepared, cured in water tank, and tested for unconfined compressive strength (UCS) and indirect tensile strength (IDT) after 28 days. Experimental results showed aggregate substitution with SST decreased both UCS and IDT of concrete. On the contrary, replacement of aggregate with RAP improved UCS values. Specimens containing RAP chips resulted in concrete with higher IDT values as compared to corresponding specimens containing RAP screenings. Addition of 40% CFA was found to improve UCS values and degrade IDT values of SST containing specimens. Statistical analysis showed that IDT of SST and RAP can be estimated as approximately 13% and 12% of UCS, respectively.