Compressive behavior of metakaolin–fly-ash-based geopolymer fiber-reinforced concrete after exposure to elevated temperatures
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Dec 31, 2024
About this article
Article Category: Research Article
Published Online: Dec 31, 2024
Page range: 180 - 196
Received: Nov 29, 2024
Accepted: Jan 10, 2025
DOI: https://doi.org/10.2478/msp-2024-0049
Keywords
© 2024 Yousef R. Alharbi et al., published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
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![Relative compressive strength: (a) normal strength concrete [36,38,39] and (b) high strength concrete [36,37,40].](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/6749616e8b676d152c2066d3/j_msp-2024-0049_fig_008.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250918%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250918T215557Z&X-Amz-Expires=3600&X-Amz-Signature=5eff620f40d390b7fc04eecfcb342755b7e5b3486112d97a4dbbe0aa57963487&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
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MK’s chemical analysis (% weight)_
Composition | SiO2 | CaO | Fe2O3 | Na2O | Al2O3 | TiO2 | SO3 | K2O | P2O5 | MgO | Others |
---|---|---|---|---|---|---|---|---|---|---|---|
Value (%) | 50.995 | 1.287 | 2.114 | 0.284 | 42.631 | 1.713 | 0.439 | 0.337 | 0.051 | 0.127 | 0.022 |
61.30 | 0.28 | 4.39 | 0.12 | 24.80 | 0.80 | 0.39 | 1.49 | 0.45 | 0.74 | 5.26 |
Summary of test results_
Specimens | Compressive strength (MPa) | Relative difference (%) |
Initial stiffness (N/mm) | Relative difference (%) |
Toughness index (%) | Relative difference (%) |
---|---|---|---|---|---|---|
M-25 | 41.94 | — | 19,853.3 | — | 2.38 | — |
M-300 | 31.79 | 24.2 | 11,560.0 | 41.8 | 1.77 | 25.3 |
M-500 | 23.00 | 45.2 | 31,88.9 | 83.9 | 1.38 | 41.9 |
MS-25 | 45.32 | — | 23,696.7 | — | 2.91 | — |
MS-300 | 32.85 | 27.5 | 7,300.0 | 69.2 | 2.25 | 22.8 |
MS-500 | 24.80 | 45.3 | 2,387.5 | 89.9 | 1.87 | 35.7 |
MSP-25 | 45.10 | — | 19,933.7 | — | 3.07 | — |
MSP-300 | 34.44 | 23.6 | 10,933.3 | 45.2 | 2.19 | 28.5 |
MSP-500 | 26.73 | 40.7 | 4,096.6 | 79.4 | 1.78 | 41.9 |
Fiber characteristics_
Properties | Fiber | |
---|---|---|
SF | PVA | |
Shape | Hooked ends (circular cross section) | Straight (circular cross section) |
Diameter (mm) | 0.75 | 0.06 |
Length (mm) | 60 | 12 |
Aspect ratio | 80 | 200 |
Tensile strength (MPa) | 1,225 | 1,600 |
Young’s modulus (MPa) | 200,000 | 35,000 |
Density (kg/m3) | 7,850 | 1,300 |
Test matrix utilized in the experimental scheme of the current study_
Mixture ID | Specimens ID | Temperatures (°C) | Fiber volume | No. of specimens | ||
---|---|---|---|---|---|---|
SF | PVA | Total | ||||
M0 | M-25 | 25 | — | — | — | 3 |
M-300 | 300 | 3 | ||||
M-500 | 500 | 3 | ||||
MS | MS-25 | 25 | 1% | — | 1% | 3 |
MS-300 | 300 | 3 | ||||
MS-500 | 500 | 3 | ||||
MSP | MSP-25 | 25 | 0.7% | 0.3% | 1% | 3 |
MSP-300 | 300 | 3 | ||||
MSP-500 | 500 | 3 | ||||
Total no. of specimens | 27 |
GPC mixture proportions in kg/m3_
Material | Weight | |
---|---|---|
MK | 277.2 | |
FA | 118.8 | |
NaOH solution | 92 | |
Na2SiO3 solution | 291.3 | |
Fine aggregate Crushed limestone (max size: 4.75 mm) | 449.8 | |
White sand (max size: 2 mm) | 148.4 | |
Coarse aggregate Crushed limestone, max size: 10 mm) | 1365.8 |