Effects of carbonation on CO2 capture and the mechanical properties of concrete with amine sorbents

Abstract

Carbon dioxide (CO2) uptake and mechanical strength of concrete with and without CO2 philic amine sorbents were assessed. Cement pastes with three amine-based sorbents (5-amino-1 pentanol, piperazine, 3-amino-1-propanesulfonic) were hydrated for 28 days. They were then investigated for CO2 uptake and compressive/bending strength. The CO2 in the atmosphere was sequestrated into the concrete as simulated carbonation weathering occurred, and the CO2 uptake was measured via thermogravimetric analysis. CO2 uptake increased when CO2 philic amine sorbents were mixed into the concrete specimens, with 5-amino-1-pentanol and piperazine showing the best efficiency in CO2 uptake (5-amino-1-pentanol: 2.44%, piperazine: 2.24%). The compressive and bending strengths also increased with carbonation. The strength of the concrete with CO2 philic sorbents was higher than that of the ordinary concrete due to the microstructure densification of the structures, indicating that urban CO2 sequestration can be performed using concrete structures without damaging their structural strength.