凍害(2)

[V-566] Influence of air bubble control using anti-foaming admixture and air-entraining admixture on freeze-thaw resistance of concrete.

〇Kazuhide Saito¹, Ryuhei Kobayashi¹, Ryosuke Saito¹, Tetsuya Oyamada², Shunsuke Hanehara² (1.Takemoto Oil&Fat, 2.Iwate University)

Keywords:frost damage, air-entraining admixture, anti-foaming admixture, freezing damage resistance, freeze-thaw resistance, bubble spacing factor

AE and high range water-reducing admixture containing a polycarboxylic acid-based polymer as a main component has high air entrainment, and the entrained air bubbles become coarse, so an anti-foaming admixture is added to suppress the entrapment of coarse air bubbles and fine entrained air is entrained. In general, many commercial AE and high range water-reducing admixture contains a certain amount of defoamer components. Therefore, this paper shows that the combined use of an anti-foaming admixture and AE admixture improves the freeze-thaw resistance, and that the freeze-thaw resistance is further improved by using an AE admixture that entrains smaller bubbles than a normal AE admixture.