STUDY ON FROST-RESISTANCE OF HIGH-STRENGTH CONCRETE

摘要

In this paper, the frost-resistance of the C60, C80 and C100 grade high-strength concrete has been studied from both macro and micro respects. The macro-study results indicate that the frost-resistance of the high-strength concrete of C60 grade don't reach 300 freeze-thaw cycles. But the frost-resistance of the C60 grade high-strength air-entrained concrete is much higher and can reach 1200 over freeze-thaw cycles in case of fast freeze. The frost-resistance of the C80 and C100 grade high-strength concrete is so high that reached over1200 freeze-thaw in case of fast freeze. Meanwhile, after a certain freeze-thaw cycles, the flexural strength of high-strength concrete drops obviously. The micro study re-suits indicate that when its mean radius of air void of the high-strength concrete is less than 0.01cm, it has the super high frost-resistance performance. In the freeze-thaw process, the destruction of micro void structure for the C60 grade high-strength concrete is mainly destruction of the capillary pores, but for the C80 or C100 grade high-strength concrete it may be destruction of the very small capillary pores and the bigger gel pores.