Carbonation of Portland Bast Furnace Slag Cement Concrete With Fly Ash

Abstract

This paper describes how an extensive research program was performed on the rate of carbonation of concrete that was produced with ordinary portland cement, portland blast furnace slag cement, and portland fly ash cement, both with replacement of cement by fly ash and without. After various periods of wet curing, concrete samples were exposed to various exposure conditions. The wet curing ranged from 1 to 90 days, the exposure concerns outdoor sheltered from rain and at 20°C, 65 percent relative humidity in the laboratory. For the various exposure conditions, a relation has been found with respect to the carbonation rate as a function of the compressive strength at 7 days or at 28 days per type of cement and for all types of cement when the lime content is involved. Results of measurements over a period up to 2 years are also presented in the paper.