Accelerated carbonation of reactive magnesium oxide cement (RMC)-based composite with supercritical carbon dioxide (scCO2)

Municipal Solid Waste Incineration Ash-Incorporated Concrete: One Step towards Environmental Justice

“…Concentrated CO 2 is precious and in a shortage in the concrete industry. Concentrated CO 2 is the key raw material of many types of alternative cement (e.g., carbonated MgO cement [136][137][138], CaCO 3 -based cement [139,140], carbonated wollastonite [141], and carbonated magnesium silicate [142]). The hardening and strength development of the carbonation-based cement systems rely on the uptake of concentrated CO 2 .…”

Mechanical and microstructural changes in reactive magnesium oxide cement-based concrete mixes subjected to high temperatures

“…Lorentz distribution was chosen with manually selected initial peak locations. Iterations were subsequently performed to achieve a respective coefficient of determination R 2 greater than 0.99. prevented the progress of the carbonation reaction and reduced the rate of strength gain [26,70]. As a result, C20 samples exhibited a marginal strength gain to 58 MPa at 14 days and 60…”

“…The significant enhancement in the mechanical performance within RMC samples with hydration agents and/or nucleation seeding under the accelerated carbonation was fundamentally attributed to an increase in the carbonation content and formation of HMCs of larger morphologies [5,17,18,21,25]. Supercritical CO2 (scCO2) was recently shown to lead to a mature strength development of RMC-based composites within hours of exposure and enhance the CO2 sequestration content [26]. XRD phase quantification with Rietveld refinement showed that the HMCs were predominantly composed of nesquehonite and hydromagnesite under prolonged carbonation [27].…”

Advances in the hydration of reactive MgO cement blends incorporating different magnesium carbonates

“…When compared to Portland cement (PC), reactive MgO cement (RMC) presents lower calcination temperatures and ability to be fully recycled [1][2][3][4]. While a ton of RMC results in the emission of 1100 kg of CO 2 (in comparison to 866 kg of CO 2 per ton of PC) [5], its ability to absorb CO 2 permanently could reduce RMC's net emissions and enable it to be considered as a sustainable binder [6][7][8]. The sequestration of CO 2 within hydrated RMC formulations leads to hydrated magnesium carbonates (HMCs) that provide a dense microstructure and establish a binding network, leading to strength development [9][10][11].…”