Investigation of carbon-capture property of foam concrete using stainless steel AOD slag

Abstract

This study investigated the effect of CO2 curing on the physical properties of foam concrete with porous structures using stainless steel-argon oxygen decarburization (ST-AOD) slag and fly ash. Foam concrete with higher porosity and more open pores allows more carbon dioxide to penetrate the matrix to improve carbon capture properties. Foam concrete was cured according to two methods: CO2 curing and normal curing. In the results of measuring the compressive strength, the specimens that used ST-AOD slag and fly ash all showed increase of strength by CO2 curing. Particularly, the specimens, in which 30% of OPC was replaced with the ST-AOD slag, demonstrated that the strength increase by CO2 curing was higher than that of Plain. The SEM observation showed that the hydrates produced by carbonation of ST-AOD slag were mainly calcite. The Brunauer-Emmett-Teller (BET) analysis results showed that the calcite produced by CO2 curing usually filled the micro-pores of less than 10 nm diameter. TG-DTG revealed that the CO2 uptake and calcite content were increased by mixing ST-AOD slag and fly ash. From the experimental results, it can be concluded that CO2 uptake of foam concrete is higher than that of normal concrete. © 2020 Elsevier Ltd