http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
오늘 본 자료
박재성,구봉근,김유식,라재웅,임찬욱,양승규 충북대학교 건설기술연구소 1998 建設技術論文集 Vol.17 No.2
The purpose of this study as to recycle the waste concrete which is generated in large quantities as crushed stone in construction works. In order to achieve these, this study deals with the comparative analysis on the workability and engineering properties of recycled aggregate classified by the factors such as aggregate composition and W/C. Also in the study, the application of recycled aggregate concrete to the concrete structure is examined. The compressive strength of 28days' curing ages of recycled aggregate concrete manufactured by this experiment manifest 356 kgf/㎠ in case of 40% water-cement ratio, 323 kgf/㎠ in case of 45% water-cement ratio, 318 kgf/㎠ in case of 50% water-cement ratio. It is difficult to use the recycled aggregate concrete in case of 50% water-cement ratio because of low compressive strength in early age. If quality control is practiced enough about the suitable mixing proportion, used of superplasticizer and proper water cement ratio, the recycled aggregate concrete is able to used sufficiently in the construction field.
구봉근,김유식,라재웅,주봉철,김창운 충북대학교 건설기술연구소 1999 建設技術論文集 Vol.18 No.2
This study will make reinforced concrete beams using recycled aggregates, and make an analysis of characteristics by experiment. First, this study will compare and consider characteristics of mechanical behavior for the rate of recycled coarse aggregate substitution. Second, it will look into effects of the shear span to depth ratio (a/d). Also, it will present appropriate methods of appraisal for reinforced concrete beams using recycled aggregates, through comparing experiment values with prediction values of specification, because of supporting basic data for real design. Major experimental variable was the shear span to depth ratio, which was changed from 1.5 to 3.0. For each case of variables, the rate of recycled coarse aggregate substitution was changed to 0, 30, 50, and 100 percent. The total sixteen specimens were producted and tested. From the analysis of the test data, the following conclusions can be drawn: Generally, reinforced concrete beams using recycled aggregates were showing a similar tendency with reinforced concrete beams using broken stones about shear behaviors. So it can be applied to real structures. Using recycled aggregates decreased in diagonal shear strength (V_c). Because Diagonal cracks appeared at 74∼79% of ultimate shear strength, but in the case of using broken stones, diagonal cracks appeared at 82% of ultimate shear strength. Shear beams under 2.0, that's value of a/d, ware sin the failure mode of deep beam. So definition of deep beam is appropriate it under 2.0, that's value of a/d, in the case of shear beams using recycled aggregate.