본 연구에서는 코어직경에 따른 시멘트 모르타르의 부착강도 변동 특성을 분석하기 위하여, 코어직경 50mm 부착강도 13개 데이터와 코어직경 75mm 부착강도 17개 데이터를 활용하여 분석하였다. 부착강도의 평균값을 비교하면 코어직경 75mm의 값이 코어직경 50mm의 값에 비해 10.5% 정도 크게 나타났으며, 코어직경에 따른 부착강도의 변동계수(Coefficient of Variation) 값을 비교·분석한 결과 코어직경 75mm의 변동계수가 모든 시험 회차에서 상대적으로 작게 나타났다. 그러므로, 코어 직경에 따른 부착강도의 변동성을 최소화 하기 위해서는 코어직경 75mm를 사용하는 것이 바람직할 것으로 판단된다.

Asphalt concrete overlay is the most commonly used resurfacing technique for aged concrete pavement. However, the performance of the asphalt concrete overlay depends on how strongly the asphalt layer bond with concrete layer. Weakened bonding at the interface of asphalt and concrete pavement may contain water and deicer and eventually lead to pavement deterioration such as pothole, reflection crack, and concrete degradation. Accordingly, tensile bonding tests were conducted with various water proofing materials and the bonding performances were evaluated by using different pavement material. Emulsified asphalt waterproofing material showed superior quality in bonding, and acrylastic material waterproofing material showed inferior quality in bonding.

Asphalt overlay on top of concrete pavement is commonly used in Korea. But water and deicing chemical can penetrate asphalt layer and stay at the boundary of asphalt and concrete layer, which cause accelerated degradation of concrete. Theoretically asphalt mixture is impermeable, but water can penetrate where improper compaction applied area or boundary area. Accordingly, optimum asphalt contents in existing mix design were modified in order to increase impermeability and test road was constructed with the modified method. The testing field site was monitored for 17 months and the performance of the test road was similar to the road used conventional mix design, although modified mix design used for the test road has 30% less air void. Thus, reduced pavement deterioration is expected on the concrete pavement rehabilitation with asphalt overlay

Cold-mixed asphalt concrete is used to resurface locally damaged area as patching technique. However, due to the durability of Cold-mixed asphalt concrete, resurfacing needs recur for the patching conducted area. Throughout marshall stability tests, residual stability tests, and wheel tracking tests of 12 different resurfacing materials, additional quality standards were suggested in this study such as higher than 7350N in stability test, air void range from 3% to 10%, and 750/mm in dynamic stability.

64 percent of overall highway is concrete pavement, and the age of Chungbu highway is over. It is desirable to use same material for the maintenance of concrete pavement, but asphalt overlay is commonly used because lane closure time is directly related to the curing time of concrete. However, there is no study conducted on structural performance of concrete pavement after damaged surface cutting. Therefore, falling weight deflectometor was used to evaluate structural evaluation of both asphalt pavement overlay concrete after cutting and asphalt pavement overlay, and 1.5 time higher deflection and 5.5% reduced load transfer efficiency were observed in cutting overlay comparing against non-cutting overlay. These observations indicate that there is high possibility of reflective cracking in case of cutting overlay due to increased deflection and reduced load transfer efficiency