Influence of cement and expansive additive types in the performance of self-stressing and self-compacting concretes for structural elements

•This work researches the properties of self-stressing SCC for structural elements.•Expansive additives influence self-compacting properties and compressive strength.•Without watering, type G additives promote larger total longitudinal expansion.•The cement chemical composition influences the type K additive efficacy.•Different microstructural mechanisms are responsible for the obtained expansion. Self-stressing self-compacting concretes were developed for structural elements, considering two types of expansive additives (types K and G) and two cement types. The influence of different parameters in their performance was evaluated. The addition of expansive additives resulted in compressive strength reductions that mainly depended on the total expansion reached. This total expansion depended on the alumina and sulfates contents of cement when using type K additive and, without watering, type G promoted larger total longitudinal expansion by forming amorphous calcium hydrated agglomerates. In contrast, when using type K additive, an indiscriminate formation of ettringite was observed.