Design of carbonated r‐MgO‐PC binder system: Effect of r‐MgO replacement level and water‐to‐binder ratio

Abstract

This study investigates the influence of reactive MgO (r‐MgO) replacement levels and water‐to‐binder (w/b) ratios on the compressive strength, carbonation front, and pore structure of mortars with r‐MgO and Portland cement (r‐MgO‐PC) as binder. The experimental results reveal that an increase in the w/b ratio decreases the carbonation degree for mortars with 20% r‐MgO, but increases the carbonation degree for mortars with 60% r‐MgO. The r‐MgO replacement level together with the w/b ratio and carbonation degree impacts the type and quantity of the carbonation products, namely Mg‐calcite, nesquehonite and the hydrated amorphous Mg carbonate, which affects the pore structure and compressive strength of the matrix. The maximum strength for mortars with 20% r‐MgO occurs at the lowest w/b ratio (0.45), while the maximum strength for mortars with 60% r‐MgO occurs at the intermediate w/b ratio (0.65). A design of r‐MgO replacement level, w/b ratio in conjunction with the drying and carbonation curing regimes is needed for further advancement and application r‐MgO‐PC system.

Improved ferroelectric properties and band-gap tuning in BiFeO3 films via substitution of Mn

“…A small conveyance in polarization hysteresis loops along the direction of the positive eld in BFMO thin lms can be imputed of actors like crystallographic defects, work function difference and thermal history between top and bottom electrodes. 42,43 The piezoelectric response of the 8% Mn-BFO thin lm has been studied simply by piezoresponse force microscopy. Typical buttery loops were observed for 8% Mn-BFO sample, as presented in Fig.…”

Production of reactive magnesia from desalination reject brine and its use as a binder

“…Reactive MgO cement has several advantages when compared to Portland cement (PC), including its ability to gain high strengths by absorbing and storing atmospheric CO2 permanently in the form of stable carbonates and its recyclability at the end of its lifetime [14,34,[59][60][61][62][63][64]. In line with these advantages, the main objective of this study is to develop reactive MgO from locally available reject brine and evaluate its feasibility to be used as a binder in terms of mechanical performance and microstructural development, which has not been reported until now.…”

Influence of crack width on the stiffness recovery and self-healing of reactive magnesia-based binders under CO2-H2O conditioning

“…under a CO2 concentration of 99% and a relative humidity of ˃ 90% at room temperature), respectively [41]. Furthermore, the low solubility of RMC leads to the presence of unreacted MgO particles within the matrix [42][43][44][45][46], which is a desirable property for autogenous healing in cementitious materials that requires the availability of reactive phases for the healing of cracks [47]. Accordingly, the crack healing of RMC-based mixes subjected to various healing regimes was investigated in recent studies [48][49][50],…”