ASEA SEC 05


EFFECT OF SURFACE-PENETRANTS FOR CONCRETE UNDER FREEZE-THAW CYCLES

MASAYUKI SAYAMA, SHOICHI SAYAMA, KOJI MITANI, LIANGJUN HU, ISAMU YOSHITAKE


Abstract

Reinforced concrete (RC) structures are generally deteriorated by penetration of water and gases that induce corrosion of reinforcements. Surface-penetrants, which increase gas-penetration resistance of concrete, can improve the long-term durability of RC members. A kind of surface-treatment, such as silane penetrants, gives a high water-repellant effect to concrete. It is well known that concrete in cold regions is occasionally damaged by freezing and thawing (F-T) cycles. In a microscopic viewpoint, water-pressure in pore structures of concrete increases due to freezing. The increase of internal water pressure may be a cause of the F-T damage of concrete. It is possibly hard to ease the water-pressure in saturated concrete incorporating the water-repellant penetrant. That is, the surface-treated concrete under the F-T cycles may deteriorate seriously. To examine the effect of surface-treatment, the study conducted the F-T test (JIS A 1148) by using concrete that was painted with surface-penetrants. The foci of this investigation are to examine the F-T durability of surface-treated concretes and to compare the effect of the surface-penetrants. This paper reports the effects of the water-repellant penetrant on the F-T durability.

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