Improvement of Self-Compactability of Air-Enhanced Self-Compacting Concrete with Fine Entrained Air

Abstract

The purpose of this study is to clarify the enhancement in self-compactability of self-compacting concrete with entrained air with respect to the size of entrained air bubbles. Air bubbles entrained with a simple mixing method in which all the materials were poured at once was not suitable for enhancement in self-compactability. The authors developed a new mixing method called water-dividing mixing method, which enabled entrained air bubbles to be suitable for enhancement in self-compactability. The water-dividing method with excessive dosage of air entraining agent (AE) entrained high proportion of smaller air bubbles. The larger total surface area of bubbles due to high amount of fine entrained air reduced internal friction of fresh mortar during deformation, resulted in higher level of self-compactability of self-compacting concrete. This usefulness leads to the successful achievement of self-compacting concrete (SCC) with lower cement content with the air content of approximately 10%. The authors have named the concrete “air-enhanced self-compacting concrete (air-SCC).”