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Title |
The Resistance of Penetrability and Diffusion of Chloride Ion in Blended Low Heat Type Cement Concrete
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Keywords |
low heat type cement; blast furnace slag; fly ash; X-ray pattern; chloride ion; penetrability; diffusion; PD Index; C-S-H; pore size; MIP |
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Abstract |
Blended Low Heat type cement is ground granulated blast furnace slag and fly ash mixed ternary with ordinary portland cement. From the viewpoint of X-ray patterns of domestic LHC, the main components of cement such as C₂S, C₃A, C₃S are considerably reduced. Therefore the heat evolution of LHC paste is 42cal/g lower than of OPC paste. At early age, the compressive strength development of LHC concrete is delayed, but the slump loss ratio of fresh concrete is reduced more than 20% with elapsed time. The penetrability of LHC is lower than that of OPC by 1/7.8 with the penetrability of chloride ion into the concrete until the age of 120 days. And the PD Index value of LHC is 0.44 X 10-6 ㎠/s, which indicates only 39.3% of OPC. From the Mercury Intrusion Porosimetry test of cement past, we know that the pore size of LHC is more dense than that of OPC by production of C-S-H.
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