Suppression of alkali silica reaction using H+-type geopolymer

Abstract

An H+-type geopolymer powder was prepared by grinding a Na+-type geopolymer hardened paste and processing it with sulfuric acid. At pH 7, the extent of cation exchange with Na+ and K+ ions of the H+-type geopolymer powder was one-fourth of that of the original Na+-form geopolymer at the same pH. The ion-exchange capacity of the H+-type geopolymer powder shows pH dependence, that is, has a tendency to increase with higher pH levels. A 10 mass% addition of the H+-type geopolymer reduced both pH and the soluble alkali quantity of the hardened cement pastes to a greater extent than when no addition to the cement paste was made. Further, the injection of cement paste of 40 mass% addition of the H+-type geopolymer suppressed expansion of Alkali-Silica-Reaction more compared to that of the non-addition one.