The effects of pozzolanic powder on foam concrete pore structure and frost resistance

摘要

Pore structure and porosity of foam concrete play decisive roles in its performance, especially in terms of frost resistance. This study aimed to explore the effect of pozzolanic powder, e.g., slag powder and silica fume on pore structure and frost resistance of foam concrete. The relationship between pore structure and frost resistance and the mechanisms of frost damage were analyzed using ultrasonic nondestructive testing, image analysis, and scanning electron microscope. The results showed that when slag powder and silica fume content were 30% and 6% respectively, frost resistance maximized, with the mass-loss of 1.76% and 1.99%, and stress loss of 13.61% and 14.49%, respectively. Slag powder and silica fume reduced porosity to 0.503 and 0.513, which were 0.102 and 0.992 less than that of the control group. The number of pores sized 100-300 mu m gained an increase of 6.08% and 4.47% compared to the corresponding control group. The results also indicated that pore structure optimized when slag powder and silica fume content were 30% and 6%, respectively. (C) 2019 Elsevier Ltd. All rights reserved.