PURPOSES : On a thin epoxy overlay pavement, epoxy is placed on the existing bridge deck pavement, followed by the spraying of aggregates on it. The bond strength between the existing pavement and overlay pavement is an important factor representing the performance of the thin epoxy overlay pavement, in addition to the skid resistance and roughness. Therefore, the bond strength, skid resistance, and roughness of a thin epoxy overlay pavement constructed for field tests under various field conditions are examined in this study. METHODS : The usability of epoxy and aggregates on a thin epoxy overlay pavement is identified by testing their material properties in a laboratory. A construction test is performed using the pretreatment conditions of the existing pavement surface and the number of layers of overlay pavement as variables. The bond strength, skid resistance, and roughness are analyzed 3 d after constructing the test pavement, and immediately before and after applying repetitive traffic loadings at 6 months. RESULTS : When the existing pavement is in good condition, as in this study, the bond strength of the thin epoxy overlay pavement is affected more significantly by the existing pavement condition than the material properties of epoxy, in which destruction is indicated in the existing pavement. The skid resistance is affected primarily by the condition of the aggregates sprayed on the epoxy. The pavement on which the aggregates are well sprayed indicate a high skid resistance. The roughness is not affected by any variables, such as the pretreatment conditions, number of thin pavement layers, and repetitive traffic loadings. CONCLUSIONS : A long-term evaluation of the bond strength, skid resistance, and roughness will be conducted on a test pavement. In addition, another construction test will be performed to investigate the performance of a thin epoxy pavement overlaid on a bridge deck pavement under inferior conditions.

PURPOSES : Given that large-scale repair works of expressway bridge pavements have high maintenance cost and long traffic blocking time, the thin overlay method that maintains the existing pavement is attracting attention. In this study, because the bridge thin overlay has not been introduced in Korea yet, the basic physical properties of the epoxy thin overlay, which is mainly used for the bridge thin overlay, were investigated, and the skid resistance and bond performance were analyzed. METHODS : Basic physical property tests were performed on each of the epoxy binders, aggregates, and mixtures used in epoxy thin overlay. They were also compared and reviewed against foreign standards. The epoxy binders were tested for viscosity, gel time, and thermal compatibility. The aggregates were tested in terms of water absorption, specific gravity, and gradation. The compressive and flexural strengths of the mixtures were investigated. The epoxy thin overlay has the possibility of detachment of aggregates, so the skid resistance was tested according to the paving phase. In addition, to investigate the bond performance, which is the most important performance of the epoxy thin overlay, the bond strength test was performed by varying the moisture condition and treatment condition of the existing layer surface. RESULTS : The basic physical properties of the materials used in the epoxy thin overlays satisfied foreign standards except for the gradation of aggregates. The skid resistance did not satisfy the standard when the epoxy was exposed, whereas the skid resistance did satisfy the standard when the aggregates were exposed, even after the abrasion test. The bond strength of the epoxy thin overlay satisfied the standard in all cases. The bond strength was the highest when the relative humidity of the existing layer surface was 60%. CONCLUSIONS : The materials of epoxy thin overlay that could be obtained in Korea satisfied the basic physical property standards except for aggregate gradation. Given that the aggregate gradation could be adjusted, it can be concluded that the epoxy thin overlay could be introduced in Korea. In addition, it was confirmed that the skid resistance and bond strength of the epoxy thin overlay were high enough to be used in general road conditions. It was determined that the existing layer surface should maintain an optimal relative humidity of approximately 60% because the moisture condition affects the bond strength.

본 연구에서는 박층 포장용 다층(Multiple layer) 에폭시 폴리머 콘크리트의 적용 가능성을 검토하기 위하여 국내에서 개발된 에폭시수지에 대한 실내실험을 통해 물리적 특성 평가를 수행하였고, 시공성 및 초기 공용성 평가를 위한 시험시공을 수행하였다. 실내실험으로 강도 특성을 평가하기 위하여 압축강도, 휨강도, 인장강도, 부착강도 시험을 수행하였으며 내구 특성 평가를 위하여 염소이온침투시험, Thermal Compatibility 시험을 실시하였다. 압축강도 시험결과 40MPa 이상으로 ACI(American Concrete Institute)의 폴리머 콘크리트 기준값보다 큰 값을 나타냈으며 휨강도 시험결과는 20MPa 이상으로 기준을 만족하였다. 인장강도 시험결과 15MPa의 강도값과 60%이상의 신장율이 측정되었고, 콘크리트포장면과의 부착강도 시험결과는 2.2MPa 값을 나타내어 국제기준을 만족하는 것으로 확인되었다. 염분침투저항성 시험결과는 측정값이 0Coulomb으로 수밀성이 뛰어난 것으로 나타나 제설제 등의 염화물에 대한 저항성이 클 것으로 판단된다. Thermal compatibility 시험 후 콘크리트와 에폭시 포장층의 접착면을 살펴본 결과 균열이 발견되지 않아 콘크리트포장과 에폭시 포장층의 열팽창계수 차이로 인한 접착은 문제가 없을 것으로 판단된다. 현장 시험시공 결과 우수한 시공성과 초기 공용성을 나타내어 실용화 가능성을 확인하였다. 따라서 국내 토공부 포장과 교면포장 적용시 포장 공용성과 내구성이 크게 향상 될 것으로 기대된다.