Investigation of the Durability of 52 Year Aged RC Structures Constructed of Portland Blast-furnace Slag Cement Type-C

Abstract

This paper investigated the durability and hydration reaction of a 52-year-old RC structure to clarify the long-term durability of concrete using Portland blast-furnace slag (BFS) cement type C. The concrete was found to have undergone long-term strength development and to still retain calcium hydroxide and unhydrated BFS. Although it was observed that vaterite was produced and pore volume was increased by the carbonation reaction, C-S-H still remained and remarkable decomposition of hydration products, which is often seen in accelerated carbonation tests of concrete, was not observed. From these results, it is concluded that Portland blast-furnace slag cement type C can be applied to concrete structures that require long-term durability.