Strength optimization and mechanism of carbon-negative mortars incorporating CaO-activated binders and chemically-strengthened carbonated recycled fine aggregates
Randomized trial develops and optimizes carbon-negative mortars using low-carbon binders and recycled aggregates, indicating significant strength improvements.
Key Points
This research aims to optimize a carbon-negative mortar formulation to enhance its compressive strength while promoting decarbonization in construction.
Developed a novel mortar composition replacing ordinary Portland cement with a CaO-activated binder and chemically strengthened carbonated recycled fine aggregates.
Applied L9 orthogonal design to assess the effects of varying water/binder and sand/binder ratios, along with different CRFA treatments.
Utilized SEM-EDS and X-ray computed tomography (X-CT) to analyze microstructural changes and their correlation with compressive strength.
The optimal formulation achieved compressive strength of 48.6 MPa after 28 days, surpassing all tested mixtures.
Chemical strengthening reduced interfacial transition zone thickness from approximately 7-17 μm to about 4-7 μm.
Total porosity decreased by more than 50%, and harmful pore fraction dropped from 2.01% to 0.97%.