Correlation between microstructure characteristics and macroscopic behaviors of alkali residue-based foamed concrete

An innovative approach involves crafting foamed concrete utilizing alkali residue and GGBS in lieu of a portion of OPC. This study employs laboratory tests and X-ray computed tomography (X-CT) to delve into the microstructural attributes of alkali residue-based foamed concrete (A-FC), evaluating their impact on physical and mechanical traits. Results demonstrate that the behavior of foams in A-FC - deformation, coalescence, or rupture - arises from the interplay of gravity drainage, surface tension drainage, air pressure disparity, and slurry extrusion pressure, leading to diverse pore sizes and shapes. Divergence in macroscopic physical and mechanical characteristics of A-FC primarily stems from significant disparages in compression, thermal, and electrical conductivity, as well as water absorption, between pores and pore walls. Furthermore, during the solidification process, solid particles (CaCO3, AFt, AFm, and Fs) bind together through C-S-H and C-A-H, culminating in a robust skeletal structure and yielding exceptional performance in A-FC.