This specification covers coal fly ash and raw or calcined natural pozzolan for use in concrete where cementitious or pozzolanic action, or both, is desired, or where other properties normally attributed to fly ash or pozzolans may be desired, or where both objectives are to be achieved. Fly ash and natural pozzolans shall conform to the prescribed chemical composition requirements and physical requirements. The materials shall be tested for fineness, strength activity index, water requirement, soundness, and autoclave expansion or contraction.
Область применения1.1 This specification covers coal fly ash and raw or calcined natural pozzolan for use in concrete where cementitious or pozzolanic action, or both, is desired, or where other properties normally attributed to fly ash or pozzolans may be desired, or where both objectives are to be achieved.
| Class | ||
N | F | C | |
Silicon dioxide (SiO2) plus aluminum oxide (Al2O3) plus iron oxide (Fe2O3), | 70.0 | 70.0 | 50.0 |
Sulfur trioxide (SO3), max, % | 4.0 | 5.0 | 5.0 |
Moisture content, max, % | 3.0 | 3.0 | 3.0 |
Loss on ignition, max, % | 10.0 | 6.0A | 6.0 |
| Class | ||
N | F | C | |
Fineness: |
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Amount retained when wet-sieved on 45 μm (No. 325) sieve, max, % | 34 | 34 | 34 |
Strength activity index: A |
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With portland cement, at 7 days, min, percent of | 75B | 75B | 75B |
With portland cement, at 28 days, min, percent of | 75B | 75B | 75B |
Water requirement, max, percent of control | 115 | 105 | 105 |
Soundness: C |
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Autoclave expansion or contraction, max, % | 0.8 | 0.8 | 0.8 |
Uniformity requirements: |
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The density and fineness of individual samples |
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Density, max variation from average, % | 5 | 5 | 5 |
Percent retained on 45-μm (No. 325), max variation, | 5 | 5 | 5 |
| Class | ||
N | F | C | |
Increase of drying shrinkage of mortar bars at 28 days, max, difference, in %, | 0.03 | 0.03 | 0.03 |
Uniformity Requirements: |
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In addition, when air-entraining concrete is specified, the quantity of air- | 20 | 20 | 20 |
Effectiveness in Controlling Alkali-Silica Reaction:B |
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Expansion of test mixture as percentage of low-alkali cement control, at 14 | 100 | 100 | 100 |
Effectiveness in Contributing to Sulfate Resistance:C |
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Procedure A: |
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Expansion of test mixture: |
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For moderate sulfate exposure after 6 months exposure, max, % | 0.10 | 0.10 | 0.10 |
For high sulfate exposure after 6 months exposure, max, % | 0.05 | 0.05 | 0.05 |
Procedure B: |
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Expansion of test mixture as a percentage of sulfate resistance cement | 100 | 100 | 100 |