Characterization and permeability of cement-based materials containing calcium fluoride sludge

This study was aimed to investigate calcium fluoride sludge waste resource reuse, and explore the feasibility of calcium fluoride sludge in cement-based materials used to replace the cement. The mechanical properties and durability of cement-based materials containing calcium fluoride sludge were performed using resistance test, absorption test, initial surface absorption tests, dry shrinkage test, compressive strength test, mercury intrusion porosimetry and scanning electron microscopy observation. The results indicated that partially replacing cement with calcium fluoride sludge improved the compressive strength, permeability and pore-structure, as well as 10% replacement of cement seems to give superior mechanical properties and durability due to the denser microstructures. Such dense microstructures observed in scanning electron microscopy images and narrow pore size distribution determined by mercury intrusion porosimetry. (C) 2018 Elsevier Ltd. All rights reserved.