STUDY ON THE ENHANCEMENT OF COMPRESSIVE STRENGTH OF ALUMINA CEMENT PASTE BY CARBONATION REACTION

Abstract

For alumina cement, the effects of temperature and humidity and the problem of crystal transition are of concern as major factors affecting the long-term strength. On the other hand, it has been reported that the strength of alumina cement exposed for a long period of time decreases due to crystal transition and then increases again. It has also been reported that significant carbonation has been observed. In this study, we paid particular attention to the carbonation and investigated and discussed the strength improvement of alumina cement paste by carbonation. The results showed that the compressive strength increased with the progress of carbonation up to 28 days of age, and the carbonation reached the whole extent. The alteration of the paste was considered to be due to the increase of amorphous material with the decomposition of crystalline hydrate by the progress of carbonation reaction.