PERMEABILITY EVOLUTION OF YOUNG CONCRETE STUDIED BY ELECTRICAL RESISTIVITY MEASUREMENT

Author(s): Jun Chen, Xianyu Jin and Nanguo Jin
Paper category: Proceedings
Book title: Proceedings of CONSEC13 Seventh International Conference on Concrete under Severe Conditions - Environment and Loading Volume I
Editor(s): Z.J. Li, W. Sun, C.W. Miao, K.Sakai, O.E. Gjørv, N.Banthia
ISBN: 978-2-35158-124-7
e-ISBN: 978-2-35158-134-6
Publisher: RILEM Publications SARL
Publication year: 2013
Pages: 286-292
Total Pages: 961
Language : English

Abstract: In this paper, the permeability evolution of young concrete was studied by a brand-new experimental device designed on non-contact electrical resistivity measurement. The device showed high sensibility in detecting the percolation threshold of the penetrating solution (1mol/L NaCl solution). The critical percolating time tp for concrete samples with various water to cement ratio were measured at the ages of 12 h, 1 d, 3 d, 7 d, 14d and 28 d, and the average values of solution permeation rate were calculated. It was found that the solution permeation rate of concrete slumped in the first three days, meeting well with a notable decrease of capillary porosity during this period. While from 3d to 7d, the permeability of concrete would recover to some extent. It might be the growth of micro cracks in ITZ during this stage that accounted for this. After 7d, the solution permeation rate of concrete declined in a slow rate, and leveled off finally. The results demonstrated that 0-3d is a vulnerable period for chloride ion ingression in view of the apparently greater permeability.

Online publication : 2013
Publication type : full_text
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