PURPOSES : The purpose of this study is to verify the influences on the compactibility evaluation of WMA (Warm Mix Asphalt) mixture by laboratory experiments. METHODS : Two types of WMA additives (chemical and wax types) and two types of compactors (marshall and gyratory) are used in laboratory experiments. In addition, two types of WMA processes (wet and dry) are tested to verify the impact of manufacturing process. RESULTS : The laboratory results show that the effects of compaction method on compactibility are different depending on the type of additive. The compaction method has a significant impact on WMA mixture with chemical type additive to extent that it determines whether required criterion is satisfied, but only little on WMA mixture with wax type additive. In the case of wet process for WMA mixture manufacturing, it is hard to assess the air void of HMA mixture made of same asphalt binder used in WMA mixture since the additive has already been added in asphalt binder. And the test results show that air voids of HMA mixture vary within properties of asphalt binder. CONCLUSIONS : Through this study, it is found that compactibility of WMA mixture is affected by the compaction methods depending on the additive types and by the WMA mixture manufacturing process. Therefore, those are recommended to be considered when evaluating compactibility of WMA mixtures.

PURPOSES : The purpose of this study is to analyze the effect of ions in emulsion asphalt on recycling cold asphalt concrete and suggest the possibility of using anionic and nonionic emulsion asphalt. METHODS : In this study, indirect tensile strength, toughness, tensile strength ratio, and dynamic immersion tests were conducted to determine the effects of cation, anion, and non-ion emulsified asphalt on the cold recycled asphalt mixture. Crack resistance was evaluated through indirect tensile strength and toughness tests and the tensile strength ratio and dynamic immersion test were evaluated through tensile strength ratio and dynamic water immersion test. RESULTS : Indirect tensile strength and toughness measurement results demonstrated that the mixture using anion and non-ion emulsified asphalt tended to be higher than that using cation emulsified asphalt; this is due to the high content of reclaimed asphalt pavement with a cationic or ionic surface, which is related to the use of cation-emulsified asphalt in the mixture and has shown a low strength tendency. The tensile strength ratio measurement demonstrated that the mixture using non-ion emulsified asphalt tended to be approximately 15 % higher than that of the anion mixture. This demonstrated that the chemical additive used in the mixture showed a complete hydration reaction with the distribution to the mixture. The dynamic immersion test indicates that the aggregate film rate of asphalt is highly influenced by the surface electric charge of the new aggregate while the ionicity effect appears to be insignificant, at 75 - 85 %, when circular aggregates are used. CONCLUSIONS : High reclaimed asphalt pavement content in cold recycled asphalt mixture, as well as non-ion and anionic emulsified asphalt, is advantageous, reducing cracking and improving moisture resistance. It is believed that anions and non-ions may be better utilized than applying the existing criteria to the cold temperature recycled asphalt mixture with high reclaimed asphalt pavement content. In addition, if the scope of the emulsified asphalt is expanded, various additives can be used, which will require analysis of materials, such as fertilizers and additives.

PURPOSES: Reflection cracking has been one of the major causes of distress when asphalt pavement is laid on top of concrete pavement. This study evaluated the reflection cracking resistance of asphalt mixtures reinforced with asphalt embedded glass fiber and carbon fiber using a Texas Transportation Institute (TTI) overlay tester. METHODS : Different asphalt mixtures such as polymer-modified mastic asphalt (PSMA) and a dense graded asphalt mixture were reinforced with asphalt-embedded carbon fiber and glass fiber. For comparison purposes, two PSMA asphalt mixtures and one dense graded asphalt mixture were evaluated without fiber reinforcement. Two different overlay test modes, the repeated overlay test (R-OT) and monotonic overlay test (M-OT), were used to evaluate the reflection cracking resistance of asphalt mixtures at 0 ℃. In the R-OT test, the number of repeated load when the specimen failed was obtained. In the M-OT test, the tensile strength at the peak load and tensile strain were obtained. RESULTS : As expected, the fiber-reinforced asphalt mixture showed a higher reflection cracking resistance than the conventional nonreinforced asphalt mixtures based on the R-OT test and M-OT test. The dense graded asphalt mixture showed the least reflection cracking resistance and less resistance than the PSMA. CONCLUSIONS: The TTI overlay tester could be used to differentiate the reflection cracking resistance values of asphalt mixtures. Based on the R-OT and M-OT results, the carbon-fiber-reinforced asphalt mixture showed the highest reflection cracking resistance among the nonreinforced asphalt mixtures and glass-fiber-reinforced asphalt mixture.

아스팔트 콘크리트 포장 포토홀은 최근 차량 파손등 운전자의 쾌적한 주행에 악영향을 주고 있다. 포토 홀은 아스팔트 콘크리트 포장의 수분민감저항성이 떨어져 발생하는 파손형태로 국토교통부에서 아스팔트 혼합물의 간정인장강도비를 80% 상향 조정하였으며 80%에 미달하는 아스팔트 혼합물은 박리방지제를 사 용하도록 규정하고 있다. 본 연구에서는 아스팔트 혼합물의 수분민감 저항성을 증가시키기 위하여 박리방지제 사용하였으며, 초 기 박리방지제의 성능검증을 판별하기 위해 보일링(Boiling Water Test, ASTM D 3625-96) 시험을 실 시 하였다. 간접인장강도 시험은 시편을 7.0±0.5% 공극률로 제작하였으며, 습윤(동결융해), 건조 샘플을 나누어 실험을 진행하였고 간접인장강도(Indirect Tensile Strength)를 측정하여 간접인장강도비 (Tensile Strength Ratio)를 산정하였다. 간접인장강도 시험 분석결과 습윤시편과 건조시편의 강도 차이가 무첨가 아스팔트 혼합물에서는 차이 가 분명하게 나타났지만, 액상박리방지제 첨가 시편들에서는 근소하게 나타났다. 간접인장강도비 분석결 과 액상박리방지제 무첨가 시편은 53%, 개발한 액상방리방지제 첨가 시편은 기준치인 80% 이상으로 나 타나 미국의 상용 박리방지재와 별 차이가 없었다.

Acetylcholinesterase(AChE) is an enzyme which hydrolyses acetylcholine into choline and acetate. Glucose and Adenosine-5'-Triphosphate(ATP) are the primary energy source for the brain and therefore defects in glucose metabolism and the mitochondrial system can affect cognitive function. The fact that the level of acetylcholine(ACh), neurotransmitter, glucose and ATP, are found to be decreased in the brain of Alzheimer patients has lead us to focus on the inhibition of AChE for the developmental research of the Alzheimer's disease(AD) treatment. In this paper we describe the effects of herbal medicine 9908(滌痰化瘀湯加減) in vitro and in vivo. As herb 9908 concentraion increased, the Vmax values of AChE from Electric eel were decreased, which showed that the activity of AChE in vitro was decreased. Also herb 9908 inhibit AChE activity in vivo. When herb 9908 was orally administrated to rats, amount of glucose and ATP which are energy source in metabolism, increase in brain and blood of rats. These result are also interesting in their effects for AD treatment compare with comercial drugs such as Cognex and Aricept. Furthermore, when considering the toxic problems of the Cognex and the Aricept, these oriental medicines could be very valuable medicine for treatment of AD. Abbreviation AD: Alzhemer's disease, AChE: acetylcholinesterase, ACh: acetylcholine, ATCh: acetylthiocholine, DTNB: 5,5‘-dithio-bis-2-nitrobenzoate, ATP: Adenosine-5'-triphosphate GAPD: Glyceraldehydephosphate dehydrogenase PGK : phosphoglycerate phosphokinase