Title: Pore Size Distribution of Hardened Cement Paste in Self Compacting Concrete

Author(s): V. Boel, K. Audenaert, and G. De Schutter

Publication: Symposium Paper

Volume: 234

Issue:

Appears on pages(s): 167-178

Keywords: cement paste; limestone filler; mercury intrusion porosimetry; pore structure; self-compacting concrete; superplasticizer

DOI: 10.14359/15935

Date: 3/22/2006

Abstract:
Self compacting concrete (SCC) can be placed without any compaction, avoiding some health risks as well as environmental problems. The two essential properties of SCC are a high flowability and a high segregation resistance, obtained by the use of either a large amount of fine particles (P) or a viscosity modifying admixture and a superplasticizer. Already there is a lot of knowledge about composition and workability of SCC, however there are questions regarding long-term durability due to significant difference in the mix proportions of SCC in comparison to traditional concrete. The degradation mechanisms of cementitious materials are greatly influenced by the penetration ability of aggressive fluids, and there is an important relation between the ‘pore structure’ of solids, fluid transport properties and degradation. If the pore structure of SCC turns out to be different from traditional concrete, some changes in durability behaviour might be expected. An experimental program was set up to study the pore structure of self-compacting concrete. Mercury intrusion porosimetry (MIP) was used as a testing method. As MIP can use only small-size specimens, it is customary to study hardened cement paste specimens with similar W/C ratios and curing ages as in actual concrete. In this study tests were performed on samples of hardened cement paste of several ages in order to evaluate the relative influence of various parameters on both traditional and self compacting concrete mixtures.