Calcium sulfoaluminate (CSA) cement can be used as an alternative binder in concrete, partially or fully replacing ordinary Portland cement. While CSA cement considerably accelerates the mechanical properties development, the rapid evolution of the microstructure together with the high water demand cause rapid and large volume changes at early ages. As volume changes may lead to early-age cracking, measures to reduce them may be required In this paper, autogenous and drying shrinkage are studied in mortars prepared with Portland cement, CSA cement or a 50/50 blend as binder. Very fast self-desiccation and high autogenous shrinkage of the CSA-based mortar were observed compared to the mortar made with Portland cement. On the other hand, the early-age volume changes can be limited if a blend of the two cements is used. The blended system revealed a bi-modal trend in the evolution of self-desiccation and autogenous shrinkage, in which the initial fast self-desiccation and shrinkage enter the dormant phase after the first couple of days and again start after about 28 days.

中文翻译：

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基于硅酸盐和硫铝酸钙水泥的砂浆的自收缩和干收缩

硫铝酸钙 (CSA) 水泥可用作混凝土中的替代粘合剂，部分或完全替代普通硅酸盐水泥。虽然 CSA 水泥显着加速了机械性能的发展，但微观结构的快速演变以及高需水量会导致早期快速和大的体积变化。由于体积变化可能导致早期开裂，因此可能需要采取措施减少它们。本文研究了用波特兰水泥、CSA 水泥或 50/50 混合物作为粘合剂制备的砂浆的自收缩和干收缩。与用波特兰水泥制成的砂浆相比，观察到 CSA 基砂浆非常快速的自干燥和高自收缩。另一方面，如果使用两种水泥的混合物，则可以限制早期体积的变化。