Print Email Facebook Twitter Fracture properties and microstructure formation of hardened alkali-activated slag/fly ash pastes Title Fracture properties and microstructure formation of hardened alkali-activated slag/fly ash pastes Author Zhang, Shizhe (TU Delft Materials and Environment) Li, Z. (TU Delft Materials and Environment) Ghiassi, B. (TU Delft Materials and Environment; University of Nottingham) Yin, Suhong (South China University of Technology) Ye, G. (TU Delft Materials and Environment; South China University of Technology) Date 2021 Abstract This study presents a comprehensive experimental investigation on the fracture properties of hardened alkali-activated slag/fly ash (AASF) pastes in relation to the microstructure formation and reaction product composition. The main reaction product in AASF is C-(N-)A-S-H gel along with minor hydrotalcite phase, with the polymerization of C-(N-)A-S-H gel substantially governed by its Ca/Si ratio. Strong positive correlations are identified between the Ca/Si ratios of C-(N-)A-S-H gel and the fracture properties KIc (Jtip), whereas, the compressive strength of AASF pastes is primarily determined by its capillary porosity (>0.01 μm). The disagreements between the Ca/Si ratios and corresponding intrinsic mechanical properties of C-(N-)A-S-H gel as proof by contradiction indicate that the fracture properties KIc (Jtip) of AASF pastes could be dominated by a cohesion/adhesion-based mechanism. These findings provide promising guidance for fine-tuning the fracture properties of AASF and also advise on the tailoring strategies for high-performance composite such as strain-hardening geopolymer composite. Subject Alkali-activationCa/SiFly ashFracture toughnessMicrostructureSlag To reference this document use: http://resolver.tudelft.nl/uuid:39de093f-6b95-40d0-9835-67bf49fcf72a DOI https://doi.org/10.1016/j.cemconres.2021.106447 ISSN 0008-8846 Source Cement and Concrete Research, 144 Part of collection Institutional Repository Document type journal article Rights © 2021 Shizhe Zhang, Z. Li, B. Ghiassi, Suhong Yin, G. Ye Files PDF 1_s2.0_S000888462100096X_main.pdf 5.64 MB Close viewer /islandora/object/uuid:39de093f-6b95-40d0-9835-67bf49fcf72a/datastream/OBJ/view