| 요약2 |
In this study, basic characteristics and fire resistance characteristic of concrete were reviewed according to changes in compound materials necessary for manufacturing high strength concrete such as fly ash (FA), blast furnace slag powder (BS), silica fume (SF), limestone powder (LSP) and cement kiln dust (CKD) and in mixing ratio of polypropylene (PP) fiber. As a result, OPC, CKD and FA+SF showed occurrence of spalling when PP fiber was not mixed. Spalling was prevented with mixing of 0.05 % PP fiber or more. The result was relatively satisfactory with mass loss rate of about 8 % and residual compressive strength of 30～40 %. Also, FA, type 2 and 3 of BS, and LSP did not show spalling regardless of PP fiber ratio, showing satisfactory mass loss rate and residual compressive strength. On the other hand, spalling occurred in all mixes of PP fiber in case of liquid and powder phases of SF. SF showed most unsatisfactory result with 30～100 % of mass loss rate. The analysis suggested that it is favorable to reduce the amount of SF used in manufacturing of high strength concrete. |