1 Introduction
2 Experimental Investigation
2.1 Materials
2.1.1 Fly Ashes
Element (wt%) | FA(LCC) | FA(HCC) |
---|---|---|
Carbon | 9.40 | 19.56 |
Oxygen | 50.47 | 48.53 |
Sodium | 0.81 | 0.00 |
Magnesium | 1.08 | 0.59 |
Aluminium | 9.65 | 6.70 |
Silicon | 21.8 | 20.57 |
Potassium | 0.99 | 0.93 |
Calcium | 2.47 | 0.43 |
Titanium | 0.65 | 0.46 |
Iron | 2.68 | 2.07 |
Sulfur | 0.00 | 0.17 |
LOI | 10.2 | 20.5 |
Blaine (m2/kg) | 282 | 395 |
2.1.2 Alkaline Activators
2.1.3 Superplasticizer Additives
2.2 Mix Design and Casting Procedures
Sample | Fly ash (wt.%) | NaOH solution (wt.%) | Sodium silicate solution (wt.%) | Water (wt.%) | Sand (wt.%) | Additive (wt.%) | Water/fly ash ratio (w/b)a | Liquid/fly ash ratio (L/b)b |
---|---|---|---|---|---|---|---|---|
M-FA(LCC) | 23.7 | 1.8 | 8.9 | 1.7 | 64.0 | – | 0.32 | 0.52 |
M-FA(HCC)-1 | 23.1 | 1.8 | 8.7 | 4.3 | 62.2 | – | 0.43 | 0.64 |
M-FA(HCC)-2 | 23.4 | 5.3 | 5.3 | 2.8 | 63.2 | – | 0.39 | 0.57 |
M-FA(HCC)-S | 23.1 | 1.8 | 8.7 | 3.7 | 62.4 | 0.2 | 0.41 | 0.62 |
M-FA(HCC)-G | 23.4 | 1.8 | 8.8 | 2.8 | 63.1 | 0.2 | 0.37 | 0.58 |
2.3 Characterization Tests
2.3.1 Workability
2.3.2 Density and Pore Size Distribution
2.3.3 Mechanical Tests
2.3.4 Microstructure
3 Results and Discussion
Sample | Workability (%) | Bulk density (g/cm3) |
---|---|---|
M-FA(LCC) | 60 ± 2 | 2.15 ± 0.04 |
M-FA(HCC)-1 | 59 ± 5 | 2.01 ± 0.03 |
M-FA(HCC)-2 | 58 ± 6 | 2.11 ± 0.02 |
M-FA(HCC)-S | 61 ± 7 | 2.07 ± 0.04 |
M-FA(HCC)-G | 58 ± 6 | 2.08 ± 0.02 |