| Keywords |
Bleeding ; Fine Aggregate ; Admixtures ; Viscosity Agents ; Poly Ethylene Oxide ; Methyl Cellulose |
| Abstract |
Bleeding is a kind of material separation and defined as a phenomenon that water in concrete floats to the surface of plastic concrete after placing the concrete. By the way, bleeding not only increases W/C at the surface of concrete, reduces the compressive strength but also reduce the water tightness and the duality of concrete. For this reasons, the reduction of bleeding is required certainly for the good quality of concrete. Therefore, this paper is the study as for how the fine aggregate and admixtures factor in the mix has an influence on bleeding of concrete. According to the results, amount of bleeding shows high in order of sea sand, river sand and crushed sand when they are used as fine aggregate. Bleeding decreases as the replacement ratio of crushed sand increases, and increases remarkablely as the replacement ratio of fly ash increases. As the replacement ratio of blast furnace slag powder increases, bleeding increases a little but don't show much difference, compared with no replacement of blast furnace slag powder. Bleeding also decreases in proportion to the mixture ratio of PEO and MC viscosity agents. Based on this result, it is expected that PEO and MC viscosity agents have good effect on the reduction of bleeding. |