강섬유로 보강된 반응성 분체 콘크리트의 부착특성과 쪼갬인장강도

초록

Structural members using ultra high strength concrete which usually used with steel fiber is designed with guidelinesbased on several investigation of SF-RPC(steel fiber reinforced reactive powder concrete). However, there are not clear designmethod yet. Especially, SF-RPC member should be casted with steam(90 degree delicious) and members with SF-RPC usually usedwith precast members. Although the most important design parameter is development method between SF-RPC and steelreinforcement(rebar), there are no clear design method in the SF-RPC member design guidelines. There are many controversialproblems on safety and economy. Therefore, in order to make design more optimum safe design, in this study, we investigated bondstress between steel rebar and SF-RPC according to test. Test results were compared with previously suggested analysis method. Testwas carried out with direct pull out test using variables of compressive strength of concrete, concrete cover and inclusion ratio of steelfiber. According to test results, bond stress between steel rebar and SF-RPC increased with increase of compressive strength ofconcrete and concrete cover. Increasing rate of bond stress were decrease with increase of compressive strength of SF-RPC andconcrete cover significantly. 1% volume fraction inclusion of steel fiber increase the bond stress between steel rebar and SF-RPCwith two times but 2% volume fraction cannot affect the bond stress significantly. There are no exact or empirical equations forevaluation of SF-RPC bond stress. In order to make safe bond design of SF-RPC precast members, previously suggested analysismethod for bond stress by Tepfers were evaluated. This method have shown good agreement with test results, especially for steelfiber reinforced RPC.

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