ACCELERATED CARBON CURING: EFFECTS OF VARIED DEMOULDING TIMES ON THE CO2 UPTAKE AND COMPRESSIVE STRENGTH OF FOAM CONCRETE

Abstract

The detrimental rise in atmospheric CO2 levels led by the built sector worldwide underlines the urgent need for greener practices to reduce carbon footprint. As of today, significant progress has been made in this aspect, specifically in research towards sequestering carbon in concrete. Accelerated Carbon Curing (ACC), an enhanced Carbon Capture and Storage (CCS) technique has particularly gained traction for offering both environmental and functional advantages. More interestingly, existing literature found that CO2 or carbon curing produced better results when applied on foam concrete (FC) which proves to be more efficient than Plain Cement Concrete (PCC). This was attributed to more numerous air voids, which increases porosity and thus the total reactive surface area per volume interacting with CO2. FC could also benefit from the reported improved mechanical strength. Hence, it is worth looking further into the topic. The fundamental purpose of this paper is to reaffirm or call into question previous findings and analyse the results of modified ACC involving in-mould carbon curing. More specifically, the focus will be on uncovering the effects of varied demoulding times and how different in-mould curing durations could affect the CO2 uptake behaviour as well as compressive strength performance. Results suggest that earlier demoulding generally brought about more desirable for both CO2 absorption and strength enhancement. The findings should be useful for fine-tuning ACC procedures for carbon sequestration in concrete structures, especially the more lightweight types with higher porosity.