A STUDY ON LOCAL CRACKING OF CONCRETE EXPOSED TO SEAWATER

Abstract

On surface layer of concrete subjected to seawater action over a long period of time, cracks and weakening accompanying local expansion may occur（hereinafter referred to as seawater deterioration）. In this study, in order to estimate the cause of seawater deterioration, progress conditions of seawater deterioration were evaluated by marshalled common elements of specimens with seawater deterioration on exposure test sites and their environments. In addition, based on these, in order to grasp occurrence factors of seawater deterioration, the compositional change of hydrated cement was analyzed by thermodynamic phase equilibrium calculation, and volume change by the compositional change was estimated. From the result, it was inferred that the cause of seawater deterioration may be repetition of dissolution and precipitation of ettringite accompanying change of temperature and concentration of pore water.