Effect of reinforcement on the anisotropic expansion of concrete with CSA-based expansive additives

Abstract

Expansion properties of concrete with expansive additives (EAs) are dependent on the composition of the EAs and the nature of the external restraints. This study focuses on calcium sulfoaluminate (CSA) based EA, investigating their expansion behavior under uniaxial restraint conditions. This novel aspect of the work is highlighting the effect of restraint in one direction on the expansion in different directions (i.e. restraint and stress-free directions) as well as the overall volumetric expansion of concrete. The current work also compares the anisotropic expansion of concrete with CSA-based EA to the free lime-based EA. Experimental results reveal that the expansion of concrete in the restraint direction significantly reduces inducing stress in the concrete, while the other directions remain unaffected by the degree of restraint. The study introduces an anisotropic coefficient to quantify the effect of external restraint on expansion, showing a higher coefficient for CSA-based EA compared to free lime-based EA under similar restraint conditions. This study provides insights into the complex interplay between external restraint and expansion characteristics for CSA-based EA concrete.