EFFECT OF SEA SAND WITH DIFFERENT CHLORIDE ION CONTENTS ON THE PROPERTIES OF CONCRETE

Abstract

This article presents the results of a study that evaluated the effects of using sea sand with varying contents of chloride ions on the properties of concrete, including physical and mechanical properties as well as durability. The study was carried out on the sea sand samples with different chloride ion contents, including as-received sea sand samples with a chloride ion content of approximately 0.15%, two washed (desalted) sea sand samples with chloride ion content of 0.024% and 0.05%, and sea sand samples added with chloride salt (0.375%), which were then compared with river sand samples. The sand samples had approximately the same fineness modulus ranging from 2.3 - 2.5. The research results indicated that compared with washed sea sand and river sand, concrete mixes using sea sand with high chloride ion content increased the mixing water and reduced the slump retainability of the fresh concrete. Furthermore, early compressive strength (7 days) increased but late age strength (91 and 365 days) decreased in both standard curing and wet-dry circle curing cases. Additionally, the impermeability (water and chloride ion) and the ability to protect the reinforcement from corrosion in concrete were reduced when using sea sand with high chloride ion content compared to washed sea sand and river sand.