EFFECTS OF W/P RATIO AND LIMESTONE FILLER ON PERMEABILITY OF CEMENT PASTES

Autor: Tri Phung, Quoc, Maes, Norbert, Jacques, Diederik, De Schutter, Geert, Ye, Guang
Přispěvatelé: Jensen, Ole M., Kovler, Konstantin, De Belie, Nele
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Concrete with Supplementary Cementitious Materials
DOI: 10.13140/rg.2.2.14118.93766
Popis: Because of environmental and economic benefits, a fraction of cement is increasingly replaced by limestone fillers raising a question on to what extent limestone fillers affect the durability of cementitious materials. This work aims at understanding the effects of water/powder (w/p) ratio and limestone filler replacement on water permeability of cement pastes. A newly proposed technique using a controlled constant flow concept was applied to measure permeability of hardened cement paste samples following a factorial experimental design. It was observed that both limestone filler and w/p ratio significantly influence the water permeability. At a given w/p ratio, adding limestone filler made the microstructure coarser, especially for high w/p ratio. Nevertheless, if the comparison is based on a given water/cement (w/c) ratio instead of w/p ratio, the limestone filler replacement refined the microstructure in terms of capillary porosity and pore size distribution, resulting in permeability decreases of cement pastes. Furthermore, a modified Carmen-Kozeny relation was established which enables prediction of the permeability from capillary porosity and the critical pore diameter.
Databáze: OpenAIRE