Effects of Activators on Alkali-Silica Reaction in Alkali-Activated Slag Cement Mortars

Abstract

Abstract: The sodium silicate solution was used as activator to prepare the alkali-activated slag (AAS) cement mortars. The AAS mortars were cured in 1 mol/L NaOH solution at 80 ℃ for purpose of accelerating the alkali-silica reaction (ASR). Effects of alkali content and silicate modulus in activator on ASR expansion failure of AAS mortars were investigated. The results show that the mortars exhibit ASR hazardous expansion failure. When the Na₂O content is higher than 4% (mass fraction), the ASR expansion rates of mortars are higher than 0.1%. When the silicate modulus is in the range of 1.2 to 2.0, the ASR expansion rate is further increased. The ASR products are mainly formed in the aggregate-binder interface zone, where microcracks development is also observed. The ASR expansion occurrs in the mortars results in compressive strength loss.

Key words: alkali-activated slag cement, alkali-silica reaction, activator, expansion, strength loss

CLC Number:

TQ172

WEI Haoguang, GAO Xuan, ZHOU Shiming, ZHANG Fuyang, WANG Xiaojing, YAO Xiao. Effects of Activators on Alkali-Silica Reaction in Alkali-Activated Slag Cement Mortars[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(4): 1266-1272.

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