PURPOSES: The objective of this study is to evaluate the properties of eco-friendly waterproofing materials for bridge decks. METHODS: Various waterproofing materials and construction methods that are widely used in Korea were evaluated. Then, the problems in field application were identified. In order to solve these problems, it is necessary to improve constructability and stability. Thus, the properties of heating waterproofing membranes and waterproofing systems using recycling additives were evaluated. In addition, a field test was conducted to ensure the construct-ability and stability. RESULTS AND CONCLUSIONS : Waterproofing materials were developed using waste tires and carbon black the results of the softening point test, tensile adhesion test, and shear adhesion test. A new sheet system, which consists of mesh and vinyl, was also determined from the sheet test. The properties of waterproofing materials were better than those developed under the "A Asphalt Concrete Pavement Construction Guidelines" according to the results of laboratory tests and the report of the authorized testing agency. Finally, the field test showed that the materials met quality standards. In future research, it will be necessary to conduct continuous field tests and follow-up inspections.

PURPOSES: The purpose of this study was to develop an urgent road-repair system and perform a field applicability test, as well as discover the optimum mix design for machine applications compared to the optimum mix design for lab applications. METHODS: According to reviews of the patent and developed equipment, self-propelled and mix-in-place equipment types are suitable for urgent pavement repair, e.g., potholes and cracks. The machine-application mix design was revised based on the optimum lab-test mix design, and the field application of a spray-injection system was performed on the job site. The mixture from the machine application and lab application was subjected to a wet-track abrasion test and a wheel-tracking test to calibrate the machine application. RESULTS and CONCLUSIONS : This study showed that the binder content could differ for the lab application and the machine application in the same setting. Based on the wet-track abrasion test result, the binder contents of the machine application exceeded the binder contents of the lab application by 1-1.5% on the same setting value. Moreover, the maximum dynamic stability value for the machine application showed 1% lower binder contents than the maximum lab-application value. Collectively, the results of the two different tests showed that the different sizes and operating methods of the machine and lab applications could affect the mix designs. Further studies will be performed to verify the bonding strength and monitor the field application.

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.

최근 우리나라의 도로포장은 환경의 영향, 교통량의 증가 및 차량의 중량화 등 여러 요인에 의해 설계 수명에 이르지 못하고 조기에 노후화되어 이를 위한 유지보수가 빈번히 시행되고 있다. 유지보수로 인해 발생하는 폐아스팔트 콘크리트는 주요 건설폐기물로써 이에 대한 처리는 중대한 사회적 문제로 나타나고 있으며, 유지보수 시 공사구간 통제로 인한 차량지체현상으로 사용자비용이 발생하고 있다. 본 연구에서 는 이러한 현실적 문제를 극복하고자 폐아스팔트 콘크리트를 순환골재로 이용함과 동시에 개질 유화아스 팔트를 적용한 상온 긴급보수재료 개발에 대한 실험적 분석을 수행하였다. 개질 유화 아스팔트를 사용하여 상온에서 마샬 안정도 시험을 실시한 결과 순환골재(RAP)를 사용했을 때 신규골재(VA)를 사용했을 때 보다 1-2%의 바인더 절감 효과가 나타났으며, 성능이 더 우수함을 확인 할 수 있었다. 또한, 습윤 마모 시험을 통하여 순환골재(RAP)와 신규골재(VA)를 비교한 결과 순환골재 (RAP)의 마모저항성이 더 우수함을 확인할 수 있었다.

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.

PURPOSES : The purpose of this study was to evaluate the performance of rapid-setting polymer-modified asphalt mixtures with a high reclaimed asphalt pavement (RAP) content. METHODS: A literature review revealed that emulsified asphalt is actively used for cold-recycled pavement. First, two types of rapid-setting polymer-modified asphalt emulsion were prepared for application to high-RAP material with no virgin material content. The quick-setting polymer-modified asphalt mixtures using two types of rapid-setting polymer-modified asphalt emulsion were subjected to the following tests: 1) Marshall stability test, 2) water immersion stability test and 3) indirect tensile strength ratio test. RESULTS AND CONCLUSIONS : Additional re-calibration of the RAP was needed for laboratory verification because the results of analyzing RAP aggregates, which were collected from different job sites, did not deviate from the normal range. The Marshall stability of each type of binder under dry conditions was good. However, the Type B mixtures with bio-additives performed better in the water immersion stability test. Moreover, the overall results of the indirect tensile strength test of RAP mixtures with Type B emulsions exceeded 0.7. Further research, consisting of lab testing and on-site application, will be performed to verify the possibility of using RAP for minimizing the closing of roadways.

교면 슬래브에 균열의 발생 및 수분의 침투는 구조물 내부의 철근 및 철골을 부식시키며, 아스팔트 콘 크리트 층의 파손, 특히 동절기 노면 결빙 방지를 위해 살포된 염화칼슘의 염해 피해 등을 고려할 시 교면 방수는 필수적인 항목이다. 피해를 방지하고자 적용하는 공법 중 방수성·내유동성·내마모성이 우수한 구스아스팔트 포장을 시공하는 방법이 있다. 하지만 설비비용과 운반, 포설장비에 드는 비용이 비경제적인 단점이 있으며, 강상판 위에 시공하였을 시 고온의 열이 전달되어 구조물의 변형을 유발하고 시공 후에는 잔류 응력 및 잔류 변형의 형태로 남게 된다. 고온 시공은 변형에 대한 우려 뿐 아니라 계속해서 높은 온도를 유지해야하기 때문에 작업의 안정성이 떨어지고 있다. 플랜트에서 아스팔트를 제작 후 포설 시까 지 항시 고온을 유지 하여야 하기 때문에 안전을 요하며 작업으로 한순간의 사고로 이어질 수 있는 위험 작업군으로 분류되고 있다. 여기에 온실가스배출 이라는 추가적인 단점을 볼 수 있다. 고온에서의 아스팔트 생산 및 포장 과정에서 이를 위하여 혼합물의 가열을 위해 많은 양의 연료가 소모되고, 이산화탄소와 황산화물 등 유해가스가 많이 발생한다. 아직 해결되지 않은 문제점으로 인하여 국내에서는 방수층 용도로 기층 포장에만 적용하고 있는 실정이다. 본 연구는 기존 구스아스팔트의 포장 및 방수층의 물리적 기능을 살리면서 60℃~80℃의 중온시공이 가능한 포장 공법에 대한 내용이다. 기존의 구스아스팔트와 동일한 골재입도 및 아스팔트함량을 적용하되 중온에서 최적의 구스함량으로 골재를 코팅한 후 반응성 아스팔트를 사용하여 중온에서 시공이 가능토록 하였다. 고온시공을 중온시공이 가능하도록 함으로써 유지보수 및 시공성의 효율성을 높였으며 탄소저감 과 공사비의 절감에 유리한 공법으로 판단된다.