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Title |
Assessment of Bond Characteristics between New and Old Concrete in Various Mixtures and Joint Conditions
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DOI |
https://doi.org/10.4334/JKCI.2014.26.4.507 |
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Keywords |
시공이음부 ; 부착 ; 혼화재 ; 고로슬래그 ; 플라이애쉬 construction joint ; bond ; mineral admixture ; blast furnace slag ; fly ash |
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Abstract |
Although the construction joints of a concrete structure are properly treated with some measures, leakage has frequently occurred. A series of tests on the bond characteristics between new and old concrete were carried out in this study, assuming that the leakage at the construction joints has certain relationship with the bond of concrete. To assess the bond characteristics under various conditions, a number of specimens were made that have an interface between new and old concrete and bond strength, flexural strength and splitting tensile strength were measured. Main test variables are type and amount of mineral admixtures, treatment method of the interface and type of waterstops. In addition, the effects of placing interval between the concrete and of the age of the strength tests were investigated. The test results showed a slightly increased bond strength when applying mineral admixtures, which can be attributed to the interface filled with the calcium silicate hydrate that is formed by pozzolanic reaction. On the other hand, the bond strength was higher when the interface was treated rough and dry, and the roughness of a waterstop affected the bond capacity of the waterstop. Also, an assessment is required that considers the type of strength test because the bond strength varied according to the test methods.
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