Effectiveness of In Situ Moisture Preconditioning Methods for Concrete
Publication: Journal of Materials in Civil Engineering
Volume 12, Issue 2
Abstract
With greater emphasis now being placed on the durability of concrete and the need for on-site characterization of concrete for durability, there is an increasing dependence on the measurement of the permeation properties of concrete. Such properties can be measured in the laboratory under controlled ambient conditions, namely, temperature and relative humidity, and comparisons made between samples not affected by testing conditions. An important factor that influences permeation measurements is the moisture state of the concrete prior to testing. Moisture gradients are known to exist in exposed concretes; therefore, all laboratory tests are generally carried out after preconditioning to a reference moisture state. This is reasonably easy to achieve in the laboratory, but more difficult to carry out on-site. Different methods of surface preconditioning in situ concrete are available; however, there is no general agreement on the suitability of any one method. Therefore, a comprehensive set of experiments was carried out with four different preconditioning methods. Results from these investigations indicated that only superficial drying could be achieved by using any of the preconditioning methods investigated and that significant moisture movement below a depth of 15 mm was not evident.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Archie, G. E. (1942). “The electrical resistivity log as an aid to determining some reservoir characteristics.” Trans. Am. Inst. of Min. and Metallurgical Engrs., 146, 54–62.
2.
Basheer, P. A. M., Long, A. E., and Montgomery, F. R. (1992). “The Autoclam for measuring the surface absorption and permeability of concrete on site.” Proc., CANMET/ACI Int. Conf. Advanced Concrete Technol., V. M. Malhotra, ed., American Concrete Institute, Detroit, 107–132.
3.
Buenfeld, N. R., and Newman, J. B. (1983). “The resistivity of mortars immersed in sea-water.” Cement and Concrete Res., 16(4), 511–524.
4.
Buenfeld, N. R., and Newman, J. B. (1986). “Examination of three methods for studying ion diffusion in cement pastes, mortars and concretes.” Mat. and Struct. Paris, 20, 3–10.
5.
Bungay, J. H., Millard, S. G., and Ghassemi, M. H. (1989). “Environment effects on surface measurements.” Proc., Deterioration and Repair of Reinforced Concrete in the Arabian Gulf—3rd Int. Conf., Vol. 1, 443–457.
6.
Christensen, B. J., et al. (1994). “Impedance spectroscopy of hydrating cement-based materials: measurement, interpretation, and applications.” J. Am. Ceramic Soc., 77(11), 2789–2804.
7.
Christensen, B. J., Mason, T. O., and Jennings, H. M. (1992). “Influence of silica fume on the early hydration of portland cements using impedance spectroscopy.” J. Am. Ceramic Soc., 75(4), 939–945.
8.
Dullien F. A. L. (1992). Porous media: Fluid transport and pore structure, 2nd Ed., Academic, London.
9.
Dhir, R. K., Shaaban, I. G., Claisse, P. A., and Byars, E. A. (1993). “Preconditioning in-situ concrete for permeation testing, Part 1: Initial surface absorption.” Mag. of Concrete Res., 45(163), 113–118.
10.
Garboczi, E. J., and Bentz, D. P. (1992). “Computer based models for microstructure and properties of cement based materials.” Proc., 9th Int. Congr. on the Chem. of Cement, Vol. VI, 3–15.
11.
Hancox, N. L. (1968). “An electrical measurement of the effective cross sectional area for conduction of floe processes in cement paste.” Mag. of Concrete Res., 20(64), 171–175.
12.
Parrott, L. J. (1990). “Influence of environmental parameters upon permeability: A review of permeability of concrete as a criterion of its durability.” Rep. of RILEM Technical Committee, 116-PCD, RILEM, Paris.
13.
Schonlin, K., and Hilsdorf, H. (1987). “Evaluation of effectiveness of curing of concrete structures.” Proc., Concrete Durability: Katharine & Bryant Mather Int. Conf., Vol. 1, American Concrete Institute, Detroit, 207–226.
14.
“Testing aggregates—Methods for determination of physical properties.” (1986a). BS 812: Part 2, British Standards Institution, London.
15.
“Testing concrete—Methods for mixing and sampling fresh concrete in the laboratory.” (1986b). BS 1881: Part 125, British Standards Institution, London.
16.
Whittington, H. W., McCarter, W. J., and Forde, M. C. (1981). “The conduction of electricity through concrete.” Mag. of Concrete Res., 33(114), 48–60.
Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 12 • Issue 2 • May 2000
Pages: 131 - 138
History
Received: Jan 4, 1999
Published online: May 1, 2000
Published in print: May 2000
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.