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

AbstractAn 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.Keywords: alkali residueA-FCX-CTmicrostructure characteristiccompressive strength CRediT authorship contribution statementZhengcheng Wang: Investigation, Data curation, Writing - original draft, Writing - review & editing. Kai Wu: Methodology, Writing - review & editing, Resources. Songyu Liu: Validation, Resources, Methodology, Writing - review & editing. Lei Huang: Data curation. Xiang Zhang: Software. Mengyao Li: Data curation.Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThe study was jointly supported by the National Natural Science Foundation of China (Grant No. 42277146); Science and Technology Project of Jiangsu Traffic Engineering Construction Bureau (7621009140); Graduate Practice Innovation Program in Jiangsu Province, China (Grant No. SJCX23_0074); Fundamental Research Funds for the Central Universities (2242023K40018, 2242023K30057).