关键词: 凝灰岩;火山灰活性;热活化;水泥混合材

Abstract: Methods of XRF, XRD, TG-DTA and SEM were used to characterize the physicochemical properties of volcanic tuff, research on the mechanical and thermal -mechanical complex activation of the samples were also made respectively .Results show that: the contents of silicon and aluminum in the volcanic tuff samples are more than 75％, the samples have good grindability , whose specific surface area can reach more than 300 m 2 /kg after being grinded about 10 min in the experiment; the mechanical activated tuff sample has a good filling effect in the cementitious system , which effect mainly worked in the early hydration period, and the 28 d activity index of mortar (R28 ) is between 54％ to 58％; the thermal-mechanical complex activated tuff sample 's composition and structure changed evidently , which has favorable effect on the cementitious system both in the early and further hydration period , it's 28 d activity index of mortar can reach more than 70％.

Key words: volcanic tuff;pozzolanic activity;thermal activation;cement admixture