PURPOSES : The aim of this study is to evaluate the effects of air voids, binder content, and aggregate gradation on the indirect tensile strength (IDT) and cracking tolerance index (CTindex) of cored asphalt pavements.
METHODS : Cored samples were obtained from roads in Incheon city, and several laboratory experiments were performed. First, the cored samples were first to cut into a size appropriate for the IDT test. Subsequently, the air voids of the samples were measured. The damaged sample from the IDT test was loose mixed at 150 ℃ before the binder content was determined, which was conducted via an asphalt extraction test. Finally, the clean aggregates obtained from asphalt extraction process were analyzed in the aggregate gradation test.
RESULTS : The result shows that an increase in air voids from 4% to 8% decreases the IDT and cracking tolerance index (CTindex) by 30% and 28%, respectively. Incorporating a binder enhances the ductile behavior of the asphalt mixture, resulting in a higher CTindex. Finally, the contribution of the aggregate grade on the IDT and CTindex is negligible.
CONCLUSIONS : The IDT and CTindex are primarily affected by the air voids and binder content. A higher percentage of air voids results in a lower IDT. In addition, a higher amount of binder increases the IDT and CTindex of the cored samples. Meanwhile, the aggregate grade does not affect the IDT.
Takju lees extract is expected to be a promising material for functional food. This study was conducted in order to assess the glycemic index (GI) of Takju lees extract and its effects in an oral glucose tolerance test (OGTT). The GI for Takju lees extract was evaluated with 10 healthy young adults (Male 5, Female 5). OGTT was conducted in 20 male db/db mice, fed on a diet containing 2% Takju lees extract for 4 weeks. Those animals were subjected to OGTT after one oral administration of Takju lees extract at 2 g/kg BW. The GI of the Takju lees extract was measured at 97.97. The effects of the Takju lees extract on the oral glucose tolerance test in db/db mice evidenced no differences as compared to the control group. In conclusion, Takju lees extract is a high GI material, and it has no effect on blood glucose levels in a type II diabetic animal model. Further studies will be required to confirm its anti-diabetic effects.