In this study, the experiments and analyses were carried out in order to investigate the fracture characteristics on the adhesive at the specimen bonded with aluminum and aluminum-foam. The same conditions were given for the experiments and analyses. The results are investigated by the graph of reaction force according to displacement. It was found that the experimental and the analytical data were very similar to each other. On the basis of the data, the reliability of the analysis data could be confirmed. The notches were produced at the distances of 40, 110, 150, and 190 mm from the front of the test specimen, and the maximum reaction force was compared accordingly. It was found that the highest reaction force was generated at the front end of the adhesive and the lowest reaction force was found at the middle of the adhesive interface. Finally, when the equivalent stress in the test specimen was examined, it was found that the highest stress was obtained at the distance of 110 mm. It can be deduced. As the notch formation point are similar to the point when stress is dispersed as the adhesive is peeled off, it is possible to infer the high stress compared to other test specimens.

PURPOSES : The objective of this study is to evaluate the early adhesive characteristic of asphalt emulsions, including polymer-modified emulsions, for chip seals using the surface energy concept, the bitumen bond strength (BBS) test, and the Vialit test. METHODS : Two general methods, the BBS test and Vialit test, were applied to investigate the bond strength and the aggregate loss, respectively. A new theory, the surface free energy (SFE) theory, was used to evaluate the adhesive characteristic between the emulsion and the aggregate. Based on the theory, the contact angles were measured, and then the surface energy components were calculated. Using those components, the work of adhesion (Wa) was calculated for each emulsion. To ensure reliable results, all the tests were performed under the same conditions, i.e., at 25 ℃ for 240 minutes of curing time. For the materials, three emulsions (CRS-2, CRS-2L, and CRS-2P) and one aggregate type (granite) were employed. RESULTS AND CONCLUSIONS : Under the same conditions, the modified emulsions showed better adhesive characteristics and curing behaviors than the unmodified emulsions. In addition, there was no significant difference between the various modified emulsions. One of the important findings is that the analysis by Wa presents more sensitive results than other methods. The results of the Wa showed that the CRS-2P emulsion has the best adhesive characteristics. Consequently, the use of modified emulsions for chip seals could prevent aggregate loss and allow open traffic earlier.

플라즈마 용사법을이용하여 AISI 316 스테인레스 금속모재에 0.1mm 두께의 NiCrAlCoY2O3금속 결합층과 0.3mm 두께의 ZrO2(8wt%Y2O3) 세라믹층으로 구성된 이층 단열코팅층을 제조하였다. 코팅층의 미세조직, 금속결합층의 산화를 고찰하였으며, 900˚C에서 등은 시험과 열반복시험 후, 접합강도시험을 통하여 코팅층의 단사정 상은 열처리시간이 길어질수록 약간 증가하였다. 또한 비변태성 t'의 c/a는 용사상태에서 1.0099이였으며, 100시간 열처리 후에는 1.0115로 약간 증가하였다. 그리고 용사층의 접합강도는 열처리 시간이 길어질수록 감소하였다. 등온열처리 후에는 1.0115로 약간 증가하였다. 그리고 용사층 의 접합강도는 열처리 시간이 길어질수록 감소하였다. 등온열처리 후, 파괴는 주로 세라믹층에서 일어났으며, 반복 열처리되 시편에서는 10회 이후 대부분 금속결합층/세라믹층의 계면에서 일어났다.