Strain-hardening alkali-activated fly ash/slag composites with ultra-high compressive strength and ultra-high tensile ductility

Jian Cong Lao, Bo Tao Huang*, Yi Fang, Ling Yu Xu, Jian Guo Dai, Surendra P. Shah

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

71 Scopus citations

Abstract

This study designed and developed strain-hardening alkali-activated fly ash/slag composites (SH-AAFSC) with both ultra-high compressive strength and ultra-high tensile ductility for the first time. The developed SH-AAFSC showed a compressive strength of 94.4–180.7 MPa and a tensile strain capacity of 8.1–9.9 %, which successfully pushed the performance envelope of alkali-activated materials. A multi-scale investigation was conducted to get an in-depth understanding of the obtained mechanical properties. Results showed that higher GGBS content increased the Ca/Si ratio of C(N)ASH, leading to a further refined microstructure with reduced porosity. As w/p ratio decreased from 0.27 to 0.22, the compressive strength significantly increased but the tensile ductility slightly decreased. Notably, a strong linear relationship was observed between fiber-bridging strength and the average elastic modulus of matrix obtained from nanoindentation. The study provided an avenue to produce SH-AAFSC towards ultra-high compressive strength and tensile ductility, which are promising for resilient and sustainable infrastructures.

Original languageEnglish (US)
Article number107075
JournalCement and Concrete Research
Volume165
DOIs
StatePublished - Mar 2023

Keywords

  • Alkali-activated composites
  • Alkali-activated fly ash/slag
  • Engineered Cementitious Composites (ECC)
  • Engineered Geopolymer Composites (EGC)
  • Geopolymer
  • Strain-Hardening Cementitious Composites (SHCC)
  • Strain-Hardening Geopolymer Composites (SHGC)
  • Ultra-High-Performance Geopolymer Concrete (UHPGC)

ASJC Scopus subject areas

  • Building and Construction
  • General Materials Science

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