1 Introduction
Immersed solutions | Activators | Fluctuations of strength |
---|---|---|
Sodium sulfate | Sodium hydroxide | 4 % strength increase |
Sodium hydroxide and potassium hydroxide | 65 % strength reduction | |
Sodium silicate | 18 % strength reduction | |
Magnesium sulfate | Sodium hydroxide | 12 % strength increase |
Sodium hydroxide and potassium hydroxide | 35 % strength increase | |
Sodium silicate | 24 % strength reduction |
2 Experimental Work
2.1 Material and Mixing Procedure
Material | LOI (%) | SiO2 (%) | Al2O3 (%) | Fe2O3 (%) | CaO (%) | MgO (%) | TiO2 (%) | K2O (%) | Na2O (%) | Surface area (cm2/g) | Specific gravity |
---|---|---|---|---|---|---|---|---|---|---|---|
Taftan andesite | 1.85 | 61.67 | 15.90 | 4.32 | 7.99 | 2.04 | 0.44 | 2.12 | 3.21 | 3,836 | 2.22 |
Shahindej dacite | 10.28 | 70.13 | 11.11 | 1.27 | 2.52 | 0.92 | 0.14 | 2.25 | 1.01 | 10,621 | 2.20 |
Shahindej dacite-800 °C | 5.78 | 73.44 | 11.88 | 1.30 | 2.55 | 0.98 | 0.15 | 2.30 | 1.10 | 5,500 | 2.25 |
Mixture no. | Pozzolan (kg/m3) | KOH (kg/m3) | Na2SiO3 (cc/m3) | Water (kg/m3) | Total water (kg/m3) | Total binder (kg/m3) | Fine agg. (kg/m3) | Coarse agg. (kg/m3) | W/B % |
---|---|---|---|---|---|---|---|---|---|
ATAF1 | 325 | 66 | 34 | 158 | 180 | 403 | 578 | 1,229 | 0.45 |
ATAF2 | 272 | 72 | 37 | 171 | 195 | 357 | 702 | 1,121 | 0.55 |
ARSH | 350 | 67 | 32 | 159 | 180 | 429 | 499 | 1,283 | 0.42 |
ACSH | 350 | 67 | 32 | 159 | 180 | 429 | 499 | 1,283 | 0.42 |
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ATAF1: Activated raw Taftan pozzolan mixture with w/b = 0.45.
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ATAF2: Activated raw Taftan pozzolan mixture with w/b = 0.55.
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ARSH: Activated raw Shahindej pozzolan mixture with w/b ratio = 0.42.
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ACSH: Activated calcined Shahindej pozzolan mixture with w/b ratio = 0.42.
2.2 Sample Preparation and Test Method
Mixture no. | Material type | Curing regime | Exposure conditions |
---|---|---|---|
ATAF1* | Raw Taftan | Sealed-20 °C | In a sulfate solution after 28 days curing (in) |
In curing regime till test date (out) | |||
Sealed-40 °C | In a sulfate solution after 28 days curing (in) | ||
In curing regime till test date (out) | |||
Fog-40 °C | In a sulfate solution after 28 days curing (in) | ||
In curing regime till test date (out) | |||
Sealed-60 °C | In a sulfate solution after 28 days curing (in) | ||
In curing regime till test date (out) | |||
ATAF2 | Raw Taftan | Sealed-20 °C | In a sulfate solution after 28 days curing (in) |
In curing regime till test date (out) | |||
Sealed-40 °C | In a sulfate solution after 28 days curing (in) | ||
In curing regime till test date (out) | |||
Fog-40 °C | In a sulfate solution after 28 days curing (in) | ||
In curing regime till test date (out) | |||
Sealed-60 °C | In a sulfate solution after 28 days curing (in) | ||
In curing regime till test date (out) | |||
ARSH* | Raw Shahindej | Sealed-60 °C | In a sulfate solution after 28 days curing (in) |
In curing regime till test date (out) | |||
ACSH* | Calcined Shahindej | Sealed-20 °C | In a sulfate solution after 28 days curing (in) |
In curing regime till test date (out) |
2.3 Test Procedure
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changes in capillary water absorption (in accordance with the method specified by RILEM-CPC-11.2) (RILEM 1994) and
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compressive strengths of the specimens (according to BS: 1881: part 116: 1983),
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dimensional changes of the specimens which was measured according to ASTM C1012-95a (Astm and 1012–95a 1995), and
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the chemical phases using XRD.
2.4 Water Absorption and Compressive Strength
2.5 Expansion Test
2.6 X-ray Diffraction Test
3 Results and Discussion
Mix | Water to binder ratio (W/B) | Curing condition and temperature | Position of sampling | Sulfate phases | Mineral name of sulfate phases |
---|---|---|---|---|---|
ATAF1 | 0.45 | Sealed curing at 20 °C | Surface | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
ATAF1 | 0.45 | Sealed curing at 20 °C | Middle | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
ATAF1 | 0.45 | Fog curing at 40 °C | Surface | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
(MgAl)5(SiAl)8O20(OH)2·8H2O | Palyigorskite | ||||
K2Mg(SO4)2·4H2O | Leonite | ||||
ATAF1 | 0.45 | Fog curing at 40 °C | Middle | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
ATAF1 | 0.45 | Sealed curing at 40 °C | Surface | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
(MgAl)5(SiAl)8O20(OH)2·8H2O | Palyigorskite | ||||
K2Mg(SO4)2·4H2O | Leonite | ||||
ATAF1 | 0.45 | Sealed curing at 40 °C | Middle | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
ATAF1 | 0.45 | Sealed curing at 60 °C | Surface | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
ATAF1 | 0.45 | Sealed curing at 60 °C | Middle | Na3Al SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
ATAF2 | 0.55 | Fog curing at 40 °C | Surface | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
K2Mg(SO4)2·6H2O | Picromerite | ||||
ATAF2 | 0.55 | Fog curing at 40 °C | Middle | Na3Al(SO4) | Sodium |
K2Mg2(SO4)3
| Langbeinite | ||||
K2Mg(SO4)2·6H2O | Picromerite | ||||
ATAF2 | 0.55 | Sealed curing at 40 °C | Surface | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
ATAF2 | 0.55 | Sealed curing at 40 °C | Middle | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
ATAF2 | 0.55 | Sealed curing at 60 °C | Surface | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
ATAF2 | 0.55 | Sealed curing at 60 °C | Middle | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
ACSH | 0.42 | Sealed curing at 20 °C | Surface | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
ACSH | 0.42 | Sealed curing at 20 °C | Middle | Na3Al(SO4)3
| Sodium aluminium sulfate |
ARSH | 0.42 | Sealed curing at 60 °C | Surface | Na3Al(SO4)3
| Sodium aluminium sulfate |
K2Mg2(SO4)3
| Langbeinite | ||||
ARSH | 0.42 | Sealed curing at 60 °C | Middle | Na3Al(SO4)3
| Sodium aluminium sulfate |