Portland Cement Mortar Carbonation Assessment by Using Blue Timol Indicator

This work investigated the performance of Portland cement mortars with regard to the carbonation resistance. Mortars were made with a Portland cement with 62,2% ground granulated blast-furnace slag and cured under water for one, two, three, seven, 14 and 20 days. Normally, testing for natural carbonation is made by using a phenolftalein indicator solution; however, in this study a blue timol indicator was chosen. Carbonation rate after one year of natural exposure increases with decreasing curing time under water. Also, it increases when ground granulated blast-furnace slag content in mortars increase.