INFLUENCE OF PORE STRUCTURE ON CARBONATION OF BELITE-BASED CEMENT CONCRETE USING GROUND GRANULATED BLAST-FURNACE SLAG AT LOW WATER/BINDER RATIO

Abstract

This paper describes the influence of pore structure on carbonation of concrete with belite-based cement and ground granulated blast-furnace slag at low water/binder ratio. The model of microstructure of concrete by using the mercury intrusion porosimtory results was attempted based on the concept that microstructure consists of two defferent pores with two defferent size; ink-bottle pore and non-ink-bottle pore that does not has ink-bottle pore. As a result, it is evident that when the water/binder ratio is low, there is a good correlation between the carbonation verociry and the cumulative volume of non-inkbottle pore with the radius of 70nm or more. Besides, it is indicated that the carbonation of concrete using blast-furnace slag is strongly influenced by both the ink-bottle pore and the non-ink-bottle pore with the radius of 70nm or less because the calcium carbonate produced by the cabonarion process fills up the open of pore.