Production of self-compacting concrete with high entrained air content and mechanical properties for structural purposes

ABSTRACT

The use of self-compacting concrete is already widespread in civil construction, being used mainly in slender elements and/or with high reinforcement rates. Even so, the combined effects of self-compactability with some strategies for modifying the properties of the concrete are little known. This is the case with the air entraining admixture. Thus, the present paper seeks to evaluate the influence of air entrainment in the behavior of self-compacting concrete maintaining properties suitable for structural purposes. Some premises of interest were defined based on the use of the material for the construction of concrete walls cast in place. For this, two self-compacting concrete mixtures were produced without air entraining and strength classes of C25 and C40 and, from each of them, two other mixtures modified with air entraining admixture were produced, varying the entrained air content, in a total of six mixtures whose properties were evaluated in both fresh and hardened states. The results obtained were very satisfactory, considering that two of the self-compacting concrete mixtures with air entraining presented mechanical properties suitable for use with structural function, despite the high content of entrained air.

Keywords
Self-compacting concrete; Air-entraining admixture; Self-compactability; Compressive strength