Title:
Development and Characterization of Tension-Hardening Quarry Waste-Based Geopolymer Concrete
Author(s):
Zoi G. Ralli and Stavroula J. Pantazopoulou
Publication:
Materials Journal
Volume:
121
Issue:
3
Appears on pages(s):
53-67
Keywords:
CO2 emissions; digital image correlation (DIC); ductility; durability; geopolymer concrete; metagabbro powder; steel fibers; strainhardening; tension-hardening
DOI:
10.14359/51740704
Date:
5/1/2024
Abstract:
In light of the effort for decarbonization of the energy sector, it is
believed that common geopolymer binding materials such as fly ash
may eventually become scarce and new geological aluminosilicate
materials should be explored as alternative binders in geopolymer
concrete. A novel, tension-hardening geopolymer concrete (THGC)
that incorporates high amounts of semi-reactive quarry wastes
(metagabbro) as a precursor, and coarse quarry sand (granite)
was developed in this study using geopolymer formulations. The
material was optimized based on the particle packing theory and
was characterized in terms of mechanical, physical, and durability
properties (that is, compressive, tensile, and flexural resistance;
Young’s modulus; Poisson’s ratio; absorption; drying shrinkage;
abrasion; coefficient of thermal expansion; and chloride-ion penetration, sulfate, and salt-scaling resistance). The developed THGC,
with an air-dry density of 1940 kg/m3 (121 lb/ft3), incorporates
short steel fibers at a volume ratio of 2%, and is highly ductile
in both uniaxial tension and compression (uniaxial tensile strain
capacity of 0.6% at an 80% post-peak residual tensile strength).
Using digital image correlation (DIC), multiple crack formation
was observed in the strain-hardening phase of the tension response.
In compression, the material maintained its integrity beyond the
peak load, having attained 1.8% compressive strain at 80% postpeak
residual strength, whereas upon further reduction to 50%
residual strength, the sustained axial and lateral strains were 2.5%
and 3.5%, respectively. The material exhibited low permeability to
chloride ions and significant abrasion resistance due to the high
contents of metagabbro powder and granite sand. The enhanced
properties of the material, combined with the complete elimination
of ordinary portland cement from the mixture, hold promise for the
development of sustainable and resilient structural materials with
low CO2 emissions, while also enabling the innovative disposal of
wastes as active binding components.