Micropore Structures in Cenosphere-Containing Cementitious Materials Using Micro-CT

Cenospheres have been recently applied to increase the volume of uniform micropores in hardened cementitious materials. Therefore, application of micro-CT to cenosphere-containing binders will help better understand the micropores formed by cenospheres in the hardened materials. Accordingly, the present study prepared Portland cement paste, alkali-activated fly ash/silica fume, and alkali-activated fly ash with 60% weight replacement by cenospheres and reconstructed their micropore structures using micro-CT. From the pore structure, individual micropores were extracted and analyzed using the principal moment ratios (I-11/I-33 and I-22/I-33). Based on the moment ratios, the representative pore shapes were determined in the different pore-volume ranges. Four-factor pore compliance contribution (4-factor PCC) model was then applied to predict the influences of the micropores on the elastic moduli of the micropore/matrix composites.