TY - JOUR
T1 - Enhancing the performance of Alkali-Activated Slag-Fly ash blended concrete through hybrid steel fiber reinforcement
AU - El-Hassan, Hilal
AU - Elkholy, Said
N1 - Funding Information:
The authors gratefully acknowledge the financial support provided by the United Arab Emirates University (UAEU) through grants G00003256 and G00002856 . The assistance of laboratory engineers and staff at UAEU is highly appreciated.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/12/13
Y1 - 2021/12/13
N2 - This paper investigates the mechanical properties of ambient-cured alkali-activated slag-fly ash blended concrete incorporating different hybrid combinations of steel fibers at a volume fraction of 1%. Four types of steel fibers were used with different lengths, degrees of curvature, and tensile strength. The effect of single and hybrid fiber incorporation on the performance of alkali-activated concrete was evaluated, including compressive strength, modulus of elasticity, splitting tensile strength, flexural strength, and shear capacity, toughness, and index (area under the load–deflection curve up to the peak load normalized by the compressive strength). Experimental results showed that hybridization of steel fibers at specific dosages led to superior mechanical properties compared to those without fibers or including a single type of fiber. The mechanical properties were also correlated using analytical regression models and compared to those of the literature and codified equations. A cost-benefit analysis proved that such hybrid mixes were the most cost-effective. Further, newly developed multifunctional performance indices highlighted that the optimum alkali-activated slag-fly ash blended concrete mixes for applications demanding high strength and low cost were those incorporating hybrid steel fibers. The least favorable mixes were those made without fibers or with a single type of fiber. The microstructure analysis revealed an intermix of C-A-S-H and N-A-S-H gels in alkali-activated slag-fly ash concrete.
AB - This paper investigates the mechanical properties of ambient-cured alkali-activated slag-fly ash blended concrete incorporating different hybrid combinations of steel fibers at a volume fraction of 1%. Four types of steel fibers were used with different lengths, degrees of curvature, and tensile strength. The effect of single and hybrid fiber incorporation on the performance of alkali-activated concrete was evaluated, including compressive strength, modulus of elasticity, splitting tensile strength, flexural strength, and shear capacity, toughness, and index (area under the load–deflection curve up to the peak load normalized by the compressive strength). Experimental results showed that hybridization of steel fibers at specific dosages led to superior mechanical properties compared to those without fibers or including a single type of fiber. The mechanical properties were also correlated using analytical regression models and compared to those of the literature and codified equations. A cost-benefit analysis proved that such hybrid mixes were the most cost-effective. Further, newly developed multifunctional performance indices highlighted that the optimum alkali-activated slag-fly ash blended concrete mixes for applications demanding high strength and low cost were those incorporating hybrid steel fibers. The least favorable mixes were those made without fibers or with a single type of fiber. The microstructure analysis revealed an intermix of C-A-S-H and N-A-S-H gels in alkali-activated slag-fly ash concrete.
KW - Alkali-activated concrete
KW - Analytical models
KW - Cost-benefit analysis
KW - Hybrid
KW - Mechanical properties
KW - Multifunctional performance index
KW - Steel fibers
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U2 - 10.1016/j.conbuildmat.2021.125313
DO - 10.1016/j.conbuildmat.2021.125313
M3 - Article
AN - SCOPUS:85117780526
SN - 0950-0618
VL - 311
JO - Construction and Building Materials
JF - Construction and Building Materials
M1 - 125313
ER -