One of the most accepted engineering construction concepts of underground repositories for high level waste considers the use of low pH cementitious materials. This research is focused on the development of those based on Calcium Aluminate Cements (CAC) w

The relation between basic and drying creep in tension compared to basic and drying creep in compression was investigated. The results obtained can be summarized as follows. Basic creep in compression is significantly more important than basic creep in tension. This difference increases with decreasing concrete age at loading. Compression creep and tension creep are similar under drying conditions. Analysis of these results provides insight into the physical mechanism underlying basic creep in concrete: microcrack initiation generates additional strains related to the development of additional self-drying shrinkage. We thus propose that basic creep in concrete is mainly caused by additional self-drying shrinkage under stress.