Fundamental Study on the Chemical Performance to Durability of See-Water Concrete

Reaction Products in Concrete with Sea-Water

Abstract

In this study, the resistance of concrete to seawater such as durability against sulphates and chlorides which must be examined prior to practical use at the seaside or offshore has been experimentally investigated. It was aimed to make clear the relationship between the reaction products in concrete with seawater and the deterioration process of concrete. The X-ray diffraction analysis method was applied to identify the materials produced in concrete under seawater environment, and from the strength and tendencies of the diffraction peaks the reaction process and kinds of product were investigated.
Three kinds of cement, namely the normal portland cement, blast furnace slug cement and seawater resisting cement developed for the sea grauting, two kinds of mixing water, fresh and sea water, several curing period and immersing conditions were selected.
The main results obtained were as follows: The products in normal portland cement were ettringite and calciumchloroaluminate, while those in the compound cement were calciumchloroaluminate and gypsum. It was also found that in the compound cement the content of alumina in slug should be limited to a certain amount, because alumina contributes to produce calciumchloroaluminate.