• The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal


Title: Instantaneous In-Situ Determination of Water-Cement Ratio of Fresh Concrete

Author(s): M. Mancio, J. R. Moore, Z. Brooks, P. J. M. Monteiro, and S. D. Glaser

Publication: Materials Journal

Volume: 107

Issue: 6

Appears on pages(s): 587-593

Keywords: durability; electrical resistivity; fresh concrete; nondestructive testing; quality assurance; quality control; strength; water-cement ratio

DOI: 10.14359/51664045

Date: 11/1/2010

The water-cement ratio (w/c) is one of the most important parameters determining the quality of cement-based materials. Currently, there is no practical way to accurately determine this ratio after all the ingredients of concrete have been mixed, posing a significant quality-control problem for the construction industry. A new method has been developed to address this challenge whereby an electrical resistivity probe is immersed in fresh concrete, providing an instantaneous and accurate measure of a concrete’s w/c. Experiments were conducted on eight concrete mixtures designed according to the ACI 211.1 procedure, with varying w/c (0.30, 0.40, 0.50, and 0.60) and fly ash percentages (0 and 25%). The results demonstrate a strong direct correlation between the resistivity of fresh concrete and the w/c. Average w/c estimates based on measurements using the resistivity probe were within ±0.01 of the actual values for all mixtures tested.