Effect of Concrete Rheological Properties on Quality of Formed Surfaces Cast with Self-Consolidating Concrete and Superworkable Concrete
An experimental program was undertaken to evaluate the effect of rheology of self-consolidating concrete and superworkable concrete on formed surface quality. In total, 31 mixtures with different workability and rheological properties were cast in a specially designed Z-shaped column without any mechanical consolidation. Surface defects, including surface air voids, signs of bleeding, segregation, and low filling ability were evaluated using a proposed image analysis methodology. The proposed method was successfully compared to other approaches that mainly target the detection of surface voids. Statistical models were developed between surface defect characteristics of formed surfaces cast with self-consolidating concrete and superworkable concrete and the rheological properties of the concrete. Concrete mixtures with yield stress lower than 25 Pa were found to develop superior surface finish. It was also observed that a prolonged delay in cement hydration of mixtures with yield stress lower than 50 Pa could lead to surface defects associated with bleeding. Mixtures with yield stress greater than 100 Pa exhibited considerable surface defects caused by insufficient filling ability of the concrete in the absence of mechanical consolidation. Finally, surface defects resulting from segregation were found with flowable concrete with plastic viscosity lower than 10 Pa s and yield stress lower than 100 Pa.
W. A. Megid and K. Khayat, "Effect of Concrete Rheological Properties on Quality of Formed Surfaces Cast with Self-Consolidating Concrete and Superworkable Concrete," Cement and Concrete Composites, vol. 93, pp. 75 - 84, Elsevier, Oct 2018.
The definitive version is available at https://doi.org/10.1016/j.cemconcomp.2018.06.016
Civil, Architectural and Environmental Engineering
Keywords and Phrases
Elasticity; Hydration; Image analysis; Mixtures; Quality control; Rheology; Segregation (metallography); Surface defects; Surface properties; Surface segregation; Yield stress; Air voids; Bleeding; Bugholes; Experimental program; Filling abilities; Mechanical consolidations; Rheological property; Self-consolidating concrete; Concrete mixtures; Surface air voids; Surface quality
International Standard Serial Number (ISSN)
Article - Journal
© 2018 Elsevier, All rights reserved.
01 Oct 2018