Abstract: Clay minerals incorporated in raw rock in the production process will lead to an excessive MB value of the artificial sand and a negative impact on its cement mortar performance. This paper considers large differences in physical and chemical properties between different clay minerals, and examines the influence of different clay minerals on cement mortar performance at the same artificial sand MB value, which is of great significance to the use of artificial sands with different MB values. Using expansile clay montmorillonite and non-expansile clay illite separately, we prepare artificial sands with the same MB value and the same particle gradation, and confect the mortar test specimens with the same mix proportion. Then we test the workability, mechanical performance, freezing resistance, and dry shrinkage performance of different mortars. Results show obvious difference in the performances of the mortars containing clays of different mineral types at the same MB value. In this case of artificial sand, montmorillonite mortar has worse workability than illite mortar, but its mechanical performance, freezing resistance, and dry shrinkage performance are better.

Key words: artificial sand, methylene blue value (MB value), clay, montmorillonite, illite, mortar performance