MICROSTRUCTURAL CHANGE OF BLAST FURNACE SLAG CEMENT PASTE DUE TO CARBONATION

摘要

It has been known for a while that the effect of carbonation leads to a more open pore structure in blast furnace slag cement systems and increases the vulnerability of the system to external aggressive environment. Due to the carbonation of the concrete skin, several durability problems occur such as reinforcement corrosion and freeze-thaw de-icing salt scaling. This paper draws the attention to the "slag - hydration products" interface and reduction in the paste density due to carbonation, which may be the dominant factor for certain durability problems of blast furnace cement systems, especially freeze thaw de-icing salt scaling.