ABSTRACT

Abstract Whereas blast-furnac e cemen t concrete s hav e prove d successfu l i n structure s subjected to freeze-thaw attack , their use in structures subjecte d to freeze-deicing sal t attack is still a problem. The present pape r discusses the causes of this controversy. It was foun d ou t tha t th e freeze-deicin g sal t resistanc e o f blast-furnac e cemen t concretes i s closely related to the carbonation o f the surface area . The carbonatio n of blast-furnace cemen t concretes does not only lead to an increase i n capillary porosity but als o t o metastable calciu m carbonates soluble in NaCl. Base d o n the result s of investigations ways o f improving th e freeze-deicin g sal t resistanc e o f blast-furnac e cement concretes ar e proposed. Keywords: aragonite ; calcite ; carbonation ; degre e o f hydration; freeze-deicin g sal t resistance blas t furnace cement ; frost resistance; porosity ; vaterite.