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Advances in Materials Science and Engineering
Volume 2017, Article ID 1689893, 9 pages
https://doi.org/10.1155/2017/1689893
Research Article

Fracture Surface Fractal Characteristics of Alkali-Slag Concrete under Freeze-Thaw Cycles

Department of Airfield and Building Engineering, Air Force Engineering University, Xi’an, Shaanxi 710038, China

Correspondence should be addressed to Haifu Wang; moc.qq@859404673

Received 18 March 2017; Accepted 22 May 2017; Published 18 June 2017

Academic Editor: Francisca Puertas

Copyright © 2017 Wantong Cai et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Fractal theory is introduced in fracture surface research of alkali-slag concrete (ASC) under freeze-thaw cycles; crack distribution of ASC fracture surface and freeze-thaw damage zone were calculated. Through fractal analysis of ASC sample fracture surfaces, relevance between section fractal dimension and fracture toughness and relationship between material composition and section fractal dimension are clarified. Results show that the specimen’s cracks before freeze-thaw extend along force direction gently, and there are more twists and turns after freezing and thawing; the fractal dimension also grows from 1.10 to 1.33. SEM internal microcracks’ of ASC internal microstructure after freezing and thawing is 1.37; 0 to 300 times ASC fractal dimension under freezing and thawing is between 2.10 and 2.23; with freeze-thaw times increasing, ASC fracture toughness decreases and fractal dimension increases, the fractal dimension and fracture toughness have a good linear relationship, and the fractal dimension can reflect the toughening effect of ASC. It is very feasible to evaluate ASC fracture behaviour under freezing and thawing with the fractal theory. Fractal dimension generally increases with activator solution-slag (A/S for short) or slag content. The greater the amount of A/S or slag content, the lower the dimension.