EARLY-AGE CARBONATION OF CALCIUM SILICATE HYDRATE (C-S-H) AND ITS ABILITY FOR CO2 SEQUESTRATION IN CONCRETE

Abstract

The research trend in the last years on early-age carbonation of calcium silicate hydrate, main component phase of Portland cement, in association with the process of permanent storage of CO₂ in carbonates, reducing its emissions in the atmosphere, was the objective of ongoing work. Using sodium bicarbonate (NaHCO₃) in the mixture of cementitious materials, partially replacing the cement (between 7-21 %), curing the fresh concrete was made in an early-age period. Very high value of compressive strength (43.1 MPa) was obtained very quickly being measured in the first stage of investigating the sample characteristics (after 8 hours), the reference sample reaching 30.8 MPa after 7 days and 43.3 MPa after 28 days.