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Title |
Shrinkage Properties of High Performance Concrete Depending on Specimen Size and Constraint of Reinforcing Bar
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Keywords |
고성능콘크리트 ; 건조수축 ; 자기수축 ; 팽창재 ; 수축저감제 ; 공시체 크기 ; 철근구속 |
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Abstract |
This paper reports the test results for shrinkage properties of low shrinkage high performance concrete developed by the authors dependiag on specimen size and constraint of reinforcing har. As properties in fresh concrete, low shrinkage high performance concrete(LSHPC) combined with expansive additives and shrinkage reducing admixtUre resulted in increase SF dosage due to loss of fluidity compared w_ith that of control mixture concrete, while the dosage of AE agent was decreased. LSHPC exhibited higher compressive and tensile strength than control mixture concrete. For the effect of specimen size, an increase in specimen size led to a reduction of drying shrinkage. However, it was found that the autogenous shrinkage was not affected by the specimen size and measuring method. For constraint condition, an increase in the ratio of reinforcing bar caused the slight reduction in the strain of reinforcing bar, while it increased the autogenous shrinkage stress. It was seen that LSHPC was effective to reduce autogenous shrinkage by as much as 70 % compared with control mixture high performance concrete.
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