Experimenrtal Study on Surface Alteration of Mortars Reacted with Seawater

- Process of Altered Layer Formation -

Abstract

This study aims to elucidate the surface alteration of mortar reacted with seawater. Tablet type specimen (3.5-cm diameter, 1.0-cm height), made from high-early-strength portland (HES) or alumina (AL) cement, was treated with seawater (200 mL) with salt concentration of 0.25 or 2.0 for 91 days at room temperature. Under low salt concentration, brucite and aragonite were formed. Brucite was produced remarkably at HES, while aragonite was remarkably at AL. Under high salt concentration, aragonite production was promoted. Column or needle shaped aragonite was formed on thin layer of brucite.