Estimating the Distribution of Air Voids in Concrete
Keywords:Concrete, air voids, gradation curves, simulation, linear-traverse method.
AbstractChord length measurements are used to estimate the volumetric distribution of air voids within hardened concrete samples. The accuracy of the Linear-Traverse method is questionable because chord lengths do not directly represent the actual volumes of the air voids. Using computer simulation, randomly generated concrete samples were analyzed using the Linear-Traverse method to compute the distribution of air voids, the chord length gradation curve, the chord length-to-traverse ratio, and the air void volume gradation curve. The current chord-length approach significantly underestimated the air void content. A method that estimates that air void gradation curve from the chord length gradation curve is presented. The computer simulation results are supported by a conceptual analysis. To obtain the most accurate estimate of the air void content, computer analyses showed that at least 15 traverse lines should be regularly spaced on the concrete sample.
Hover, K.C., Air Content and Unit Weight of Hardened Concrete. Chapter 28 of Significance of Tests and Properties of Concrete and Concrete Making Materials (P. Klieger and J.F. Lemond, eds.), ASTM Special Technical Publication 169c. 296-314, August 1994.
Lord, G.W. and Willis, T.F., Calculation of Air Bubble Size Distribution from Results of Rosiwal Traverse of Aerated Concrete, ASTM Bull., ASTBA, No. 177:56-61, 1950.
ASTM, Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete. ASTM C 457-98, West Conshohocken, PA, 1998.
Julien, P., River Mechanics, Cambridge Univ. Press. New York, 2002.[CrossRef]
Sobol, I.M., A Primer for the Monte Carlo Method, CRC Press, Boca Raton, FL, 1994
McCuen, R.H., Modeling Hydrologic Change, Lewis Publishers, CRC Press, Boca Raton, FL, 2003.
Hastings, N.A.J. and Peacock, J.B., Statistics Distributions, John Wiley & Sons, Inc., New York, 1975
Mendenhall, W. and Sincich, T., Statistics for Engineering and the Sciences (3rd ed.), Dellen Publ. Co., San Fran, 1992.
How to Cite
LicenseAuthors who publish with this journal agree to the following terms:
- Authors retain the copyright and publishing right, and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) followingthe publication of the article, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).