Original paper(Vol.48 No.8 pp.895)

Effects of various factors on ASR expansion in mortar treated by autoclave

Kuroda Tamotsu; Nishibayashi Shinzo; Inoue Shoichi; Yoshino Akira

Abstract:In order to clarify the effects of various factors on the ASR expansion in mortar treated by autoclave, an autoclave treatment was performed for mortar immersed in NaOH solution. As the factors, W/C ratio of mortar, the concentration of NaOH solution, the treatment pressure and the treatment period were selected.
From the experimental results, it can be concluded as follows:
(1) The expansion immediately after autoclave treatment increases as the treatment period becomes longer.
(2) For the concentration of NaOH solution and the treatment pressure, the pessimum value which the expansion immediately after autoclave treatment becomes greatest exists.
(3) For the mortar immersed in 1mol/L NaOH solution and treated at the treatment pressure of 0.05MPa and the treatment period of 48 hours, the ASR expansion immediately after autoclave treatment is equal to 42% of the expansion at the age of 6 months by mortar bar method according to JIS A 5308.

Key Words:ASR, autoclave treatment, expansion, NaOH solution, treatment pressure, treatment period