Macro/micro-pore structure characteristics and the chloride penetration of self-compacting concrete incorporating different types of filler and mineral admixture

Mohammed, Mahmoud khashaa; Dawson, Andrew; Thom, Nicholas

Abstract

The relationship between the internal pore structure features at different scales and the local micro-characteristics of the interfacial transition zone (ITZ) to the non-steady state chloride migration coefficient (Dnssm) is investigated for one normal and three types of sustainable high performance self-compacting concrete mixes. The pore structure classification at different scales and the percolation degrees of the ITZ’s pores were determined using both vacuum-saturated and Mercury Intrusion Porosimetry (MIP) techniques. Further, the local micro-permeation features of the ITZ, such as thickness, porosity and the chemistry of its hydration products is examined using the SEM coupled with the EDX analysis on polished, carbon-coated, flat specimens. Chloride movement was achieved using a modified rapid migration test.

It was deduced that the degree of percolation of the pores of the ITZ had a significant role in controlling the chloride penetration process. Further, it is proposed that the ITZ thickness might be, primarily, responsible in determining the chloride ions’ migration velocity especially when coarse and unreactive filler are used. At nano scale, it is also suggested that the critical pore diameter in the cement matrix is more significant than is the average pore diameter in controlling the chloride resistance in SCC.

Citation

Mohammed, M. K., Dawson, A., & Thom, N. (2014). Macro/micro-pore structure characteristics and the chloride penetration of self-compacting concrete incorporating different types of filler and mineral admixture. Construction and Building Materials, 72, https://doi.org/10.1016/j.conbuildmat.2014.08.070

• Journal Article Type: Article
• Acceptance Date: Aug 24, 2014
• Online Publication Date: Sep 27, 2014
• Publication Date: Dec 15, 2014
• Deposit Date: Aug 2, 2017
• Publicly Available Date: Aug 2, 2017
• Journal: Construction and Building Materials
• Print ISSN: 0950-0618
• Electronic ISSN: 1879-0526
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 72
• DOI: https://doi.org/10.1016/j.conbuildmat.2014.08.070
• Keywords: Chloride penetration, Rapid migration test, Self-compacting concrete, Microstructure, Interfacial transition zone, Cement replacement, Pores percolation
• Public URL: https://nottingham-repository.worktribe.com/output/740870
• Publisher URL: https://doi.org/10.1016/j.conbuildmat.2014.08.070
• Contract Date: Aug 2, 2017