1 Introduction
2 Materials and methods
2.1 Materials
Compound | SiO2 | Al2O3 | Fe2O3 | CaO | MgO | Na2O | K2O | MnO | P2O5 | TiO2 | H2O | SO3 | LOI |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
DE (% in mass) | 82.00 | < 0.01 | 2.00 | 0.22 | 0.30 | 0.10 | 0.20 | 0.06 | 0.34 | 0.19 | 1.15 | – | 14.18 |
OPC (% in mass) | 18 | 6.4 | 2.8 | 69 | – | 0.46 | 0.79 | – | – | 1.53 | 8.9 | 1.64 | 1.28 |
Sl. no. | Mix ID | Partial replacement of DE (%) | Addition of PPF (%) | Cement (kg/m3) | Fine aggregate (kg/m3) | Course aggregate (kg/m3) | Water (kg/m3) |
---|---|---|---|---|---|---|---|
1 | D0–P0 | 0 | 0 | 383 | 658 | 1298 | 196 |
2 | D5–P0 | 5 | 0 | 383 | 658 | 1298 | 196 |
3 | D10–P0 | 10 | 0 | 383 | 658 | 1298 | 196 |
4 | D15–P0 | 15 | 0 | 383 | 658 | 1298 | 196 |
5 | D20–P0 | 20 | 0 | 383 | 658 | 1298 | 196 |
6 | D0–P25 | 0 | 0.05 | 383 | 658 | 1298 | 196 |
7 | D0–P50 | 0 | 0.10 | 383 | 658 | 1298 | 196 |
8 | D0–P75 | 0 | 0.15 | 383 | 658 | 1298 | 196 |
9 | D0–P100 | 0 | 0.20 | 383 | 658 | 1298 | 196 |
10 | D5–P25 | 5 | 0.05 | 364 | 658 | 1298 | 196 |
11 | D5–P50 | 10 | 0.10 | 345 | 658 | 1298 | 196 |
12 | D5–P75 | 15 | 0.15 | 326 | 658 | 1298 | 196 |
13 | D5–P100 | 20 | 0.20 | 307 | 658 | 1298 | 196 |
14 | D10–P25 | 5 | 0.05 | 364 | 658 | 1298 | 196 |
15 | D10–P50 | 10 | 0.10 | 345 | 658 | 1298 | 196 |
16 | D10–P75 | 15 | 0.15 | 326 | 658 | 1298 | 196 |
17 | D10–P100 | 20 | 0.20 | 307 | 658 | 1298 | 196 |
18 | D15–P25 | 5 | 0.05 | 364 | 658 | 1298 | 196 |
19 | D15–P50 | 10 | 0.10 | 345 | 658 | 1298 | 196 |
20 | D15–P75 | 15 | 0.15 | 326 | 658 | 1298 | 196 |
21 | D15–P100 | 20 | 0.20 | 307 | 658 | 1298 | 196 |
22 | D20–P25 | 5 | 0.05 | 364 | 658 | 1298 | 196 |
23 | D20–P50 | 10 | 0.10 | 345 | 658 | 1298 | 196 |
24 | D20–P75 | 15 | 0.15 | 326 | 658 | 1298 | 196 |
25 | D20–P100 | 20 | 0.20 | 307 | 658 | 1298 | 196 |
2.2 Preparation of Concrete Specimens and Testing Methods
3 Results and Discussion
3.1 Fresh Properties and Density
3.2 Kelly Ball Test and Compaction Factor
3.3 Mechanical Properties of Concrete
3.3.1 Compressive Strength Test
3.3.2 Split Tensile Strength Test
3.3.3 Strength Relationship (Analytical)
3.4 Durability Tests
3.4.1 Water Penetration Test
3.4.2 Rapid Chloride Penetration Test
3.4.3 Sorptivity Test
3.4.4 Morphological Examination (SEM)
4 Conclusion
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Increasing the partial replacement of cement by diatomaceous earth and polypropylene fibers has direct influence on fresh properties of concrete mixtures. The incorporation of diatomaceous earth and polypropylene fibers decreases the fresh properties, the partial replacement of cement by diatomaceous earth decreases the fresh properties of concrete rather than the addition of polypropylene fibers.
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Concrete made with DE and PPF shows the strength development rather than control concrete. Diatomaceous earth enhanced the cement hydration and poly propylene fibers controlled and mitigated the growth of initial and macro cracks.
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The analytical relationship between the compressive and tensile strength of concrete showed a good predictive model with varying codes of provisions.
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The water penetration, chloride penetration and sorptivity coefficient in concrete holding diatomaceous earth and polypropylene fibers decrease rather than control mix. It should be noted that the enhancement of the durability properties of concrete by DE was more substantial than PPF.
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The SEM micro structural image exhibited that the partial replacement of cement by DE enhances the cement hydration, fills the voids between aggregates by forming ettringites and makes concrete as stronger and durable.
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The partial replacement of cement by DE beyond 15% exhibits strength reduction due to the insufficient availability of hydrated products. Likewise, PPF also shows the same nature beyond 0.75% due to the entrapped air volume.
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The analysis of all test data indicated that the concrete mix with 15% DE and 0.75% polypropylene fiber had better compressive strength, water penetration, sorptivity, decreased chloride permeability, and strength in comparison to control and other concrete mixtures.