Earticle

연구목적: 영하의 조건에서도 균열발생을 억제하고, 구조적으로 안정된 성능과 방수기능을 동시에 발 휘하는 아스팔트 포장시스템을 개발하고자 한다. 연구방법: SIS 폴리머 아스팔트, 일반 아스팔트 및 구 스아스팔트를 대상으로 다양한 온도조건에 따른 유제의 부착실험 및 혼합물의 변형강도 실험을 실시 하여 그 특성을 비교, 분석하였다. 연구결과: 아스팔트 유제의 부착강도는 SIS 폴리머 아스팔트가 일반 아스팔트 및 구스아스팔트에 비해 높은 것으로 나타났다. 아스팔트 혼합물의 변형강도는 SIS 폴리머 아 스팔트와 일반 아스팔트가 거의 동일하게 나타났다. SIS 폴리머 아스팔트 혼합물은 일반 아스팔트 혼합 물 및 구스아스팔트 혼합물에 비해 에너지흡수량이 상대적으로 높게 나타났다. 결론: SIS 폴리머 아스 팔트 혼합물의 최대하중은 구스아스팔트 혼합물에 비해 낮게 나타났지만, 열악한 온도조건에서도 최 대하중 이후에 안정적인 하중감소로 충분한 에너지흡수량을 확보하고 있고, 안정적인 파괴거동으로 미세균열 발생 등을 감소시켜 아스팔트 포장의 내구성 향상에 기여할 수 있을 것으로 판단된다.

Purpose: This paper aims to develop an asphalt pavement system with reduced cracks, structural stability and waterproofing at sub-zero temperature conditions. Method: Under various temperature conditions, SIS polymer asphalt, normal asphalt, and guss asphalt were tested for adhesion strength of the binder and deformation strength of the mixture. Result: The adhesion strength of asphalt binder was higher in SIS polymer asphalt than that of normal asphalt and guss asphalt. The deformation strength of the asphalt mixture was almost the same as that of SIS polymer asphalt and normal asphalt. The energy absorption of the SIS polymer asphalt mixture was relatively higher than that of the normal asphalt mixture and the guss asphalt mixture. Conclusion: The maximum load of the SIS polymer asphalt mixture was lower than that of the guss asphalt mixture. However, in sub-zero temperature conditions, sufficient energy absorption was secured by stable load reduction. Therefore, it is expected to improve the durability of asphalt pavement by reducing the occurrence of microcracks with stable fracture behavior.

The cement-asphalt mortar is a mixture of cement and asphalt emulsion, and is utilized as a underpouring materials for the railway track which is used to fill under slab panel space so as to provide a stabilized track support and a tool for reduction of noise and vibration. To increase the workability of grouting, this study investigates the effect of temperature on cement-asphalt mortar by analyzing its physical and mechanical properties before/after hardening according to the temperature (10, 15, 20, 25, $30^{\circ}C$). According to the test results, it is found that as for the physical property of fresh cement-asphalt mortar the more mixture temperature become higher or lower, the more fluidity become worse. But by increasing reducing agent amount and its unit quantity, the required fluidity is met. The compressive strength as physical property of hardened cement-asphalt mortar become lower when temperature is lower but taking it by and large the physical properties of cement-asphalt mortar before/after hardening aren't so affected by temperature and well satisfy the requirement. And it has proved that rate of expansion and freezing and thawing resistance aren't affected by temperature.

PURPOSES : Emulsified asphalt is critical for road construction. The objective of applying asphalt emulsion as an adhesive is to prevent the phenomenon of debonding between the upper and lower layers. The quantity and veriety of bituminous material can be varied according to the type of pavement and site conditions. The objective of this study is to reveal the optimum application rates of the emulsified asphalt materials by types of tack-coats using Interface Shear Strength(ISS). METHODS : In the research, emulsified asphalt was paved on the surface of the divided mixture. The specimens of paving asphalt emulsion were utilized to evaluate the bond strength of tack-coat materials. In the evaluation process, NCHRP Report 712 was utilized to investigate the Interface Shear Strength, which reflects the bond capacity of asphalt emulsion. Then, the optimum residual application rates by tack-coat types were determined using regression analysis. RESULTS :As a consequence of squared R values investigated from 0.7 to 1 as part of the regression analysis, the tendency of predicted ISS values was compared with the results. The optimum residual application rates of AP-3, RS(C)-4, QRS-4, and BD-Coat were determined to be $0.78{\ell}/m^2$, $0.51{\ell}/m^2$, $0.53{\ell}/m^2$, and $0.73{\ell}/m^2$, respectively, utilizing 4th regression analysis. CONCLUSIONS :Based on the result of this study, it was not feasible to conclude whether higher residual application of tack-coat material leads to improved bond capacity. Rather, the shearing strength varies depending on the type of pavement.