Effects of chloride ion in sea sand on properties of fresh and hardened concrete incorporating supplementary cementitious materials
Viet Quoc Dang, Yuko Ogawa, Phương Trinh Bùi, Kenji Kawai
Abstract
This study aims to explore the applicability of non-desalted sea sand (NSS) for concrete production by investigating the effects of chloride ion on properties of fresh and hardened concrete incorporating fly ash (FA) and ground granulated blast furnace slag (BFS). All mixtures were prepared with a constant water-to-cementitious materials ratio of 0.50. The results showed that chloride ion in NSS had no effect on the slump loss and air content reduction of fresh concrete for 60 min after mixing. Thermal analysis and pore structure results clarified that chloride ion accelerated the pozzolanic reactivity of FA and hydraulicity of BFS at early ages. The presence of chloride ion also contributed to the increase in the mechanical properties and durability (permeability and sorptivity) of concrete at later ages. The outcomes of this study could validate the potential application of NSS for concrete incorporating supplementary cementitious materials as the alternative fine aggregate at coastal areas.