Authors:
Hamid Rahmani; Nooshin Mohammadzade;
Abstract:
The application of reactive powder concretes (RPCs) will be very interesting when waste stone powders are used in the production stage. Since high cementitious material content is used in the production of RPCs, CO2 as a harmful greenhouse gas was used for carbonation curing in this study. For this purpose, waste limestone powder was substituted by 0%, 18%, 36%, and 54% of silica sand, and then specimens were cured in water up to 90 d and CO2 chamber for up to 48 h. The physical and mechanical properties of the concretes, and CO2 uptake of the specimens were measured at different ages. Results showed that the 28-day compressive strength of moist cured RPCs was higher than 100 MPa, and the properties of the RPCs were improved by increasing limestone substitution. CO2 curing of the RPCs significantly increased the compressive strength of the samples, and limestone powder substitution as silica sand significantly decreased the carbonation and autogenous shrinkages of the RPCs. Moreover, it can be recommended that carbonation curing be able to make eco-friend limestone-modified RPCs where their properties are even improved.
Keywords:
CO2 curing, Reactive powder concrete, Waste limestone powder, Sustainability