1 Introduction
2 Materials and Experiment Procedure
2.1 Materials
Element | Content (%) | Element | Content (%) | Element | Content (%) |
---|---|---|---|---|---|
SiO2 | 22.7 | Na2O | 0.27 | SO3 | 1.65 |
Al2O3 | 4.8 | K2O | 0.81 | IR | 0.42 |
Fe2O3 | 3.8 | Alkalinity equivalent | 0.8 | C3A | 6 |
CaO | 64.2 | CO2 | 0.0 | C2S | 30 |
MgO | 1.8 | C3S | 47 | L.O.I | 0.7 |
C4AF | 12 |
Relative weights in the dry state (gr/cm3) | 2.029 |
---|---|
The relative weights in the dry saturated state (gr/cm3) | 3.39 |
Apparent specific gravity (gr/cm3) | 2.53 |
The water absorbed aggregate (%) | 4.2 |
Plyometric weight with water up to line mark (gr) | 656 |
Saturated specimen weight with dry air level (gr) | 500 |
The weight of the meter with water and the specimen to the mark (gr) | 942 |
Dry specimen weight in the oven (gr) | 479.8 |
Relative weights in dry state(gr/cm3) | 2.18 |
The relative weights in the dry saturated state (gr/cm3) | 2.27 |
Apparent specific gravity (gr/cm3) | 2.38 |
The water absorbed aggregate (%) | 3.8 |
Saturated specimen weight with dry air level (gr) | 1000 |
Saturated specimens weight immersed in water (gr) | 559 |
Dry specimen weight in the oven (gr) | 192.6 |
Element | Content (%) | Element | Content (%) |
---|---|---|---|
Na2O (sodium oxide) | – | SiO2 (silicon dioxide) | 86.18 |
K2O (potassium oxide) | – | Al2O3 (aluminum oxide) | 1.44 |
TiO2 (titanium dioxide) | – | Fe2O3 (ferric oxide) | 0.2 |
P2O5 (phosphorus pentoxide) | – | CaO (calcium oxide) | 3.06 |
ZnO (zinc oxide) | – | MgO (magnesium oxide) | 1.32 |
Mn2O3 (manganic oxide) | – | SO3 (sulfur trioxide) | 0.337 |
Sulfide sulfur | – | Loss on ignition | 1.15 |
2.2 Mixture Proportioning and Specimen Preparation
2.2.1 Mixture Proportioning of Mortar
Mix design no | Water (gr) | Cement (gr) | SSA (gr) | Sand (gr) |
---|---|---|---|---|
1 | 242 | 500 | 0 | 1350 |
2 | 242 | 475 | 25 | 1350 |
3 | 242 | 450 | 50 | 1350 |
4 | 242 | 425 | 75 | 1350 |
5 | 265 | 400 | 100 | 1350 |
6 | 270 | 350 | 150 | 1350 |
7 | 280 | 250 | 250 | 1350 |
2.2.2 Mixture Proportioning of Concrete
Mix design no | Cement (Kg/m3) | Superplasticizers (Kg/m3) | SSA (Kg/m3) | Water (Kg/m3) | Sand (Kg/m3) | Gravel (Kg/m3) |
---|---|---|---|---|---|---|
1 | 15 | 0 | 0 | 11.62 | 66.6 | 44.44 |
2 | 14.25 | 0 | 0.75 | 11.65 | 66.6 | 44.44 |
3 | 13.5 | 0 | 1.5 | 11.92 | 66.6 | 44.44 |
4 | 12.75 | 0.025 | 2.25 | 11.85 | 66.6 | 44.44 |
5 | 12 | 0.05 | 3 | 11.75 | 66.6 | 44.44 |
6 | 10 | 0.075 | 5 | 11.75 | 66.6 | 44.44 |
Mix design no | Cement (Kg/m3) | Superplasticizers (Kg/m3) | SSA (Kg/m3) | Water (Kg/m3) | Sand (Kg/m3) | Gravel (Kg/m3) |
---|---|---|---|---|---|---|
7 | 4.5 | 0 | 0 | 3.96 | 22.2 | 14.8 |
8 | 4 | 0.03 | 0.5 | 3.96 | 22.2 | 14.8 |
9 | 3.5 | 0.045 | 1 | 3.96 | 22.2 | 14.8 |
10 | 3 | 0.06 | 1.5 | 3.96 | 22.2 | 14.8 |
2.2.3 Specimen Preparation
2.3 Experiment Procedure
2.3.1 X-Ray Fluorescence (XRF)
2.3.2 Sludge-Burning Incinerator
2.3.3 Powdered X-Ray Diffraction (XRD)
2.3.4 Centrifuge
2.3.5 Workability
2.3.6 Water Permeability
2.3.7 Tensile Strength
3 Results and Discussion
3.1 Results of the Tests on SSA
3.1.1 XRF
Element | Content (%) | Element | Content (%) | Element | Content (%) |
---|---|---|---|---|---|
L.O.I | 59.11 | Na2O | 1.23 | Zn | 0.54 |
Al2O3 | 3.7 | SiO2 | 10.1 | Zr | 0.1 |
Fe2O3 | 2.12 | SO3 | 1.9 | Cu | 0.07 |
CaO | 10.3 | K2O | 0.81 | Cl | 0.21 |
MgO | 1.86 | P2O5 | 7.6 | Sr | 0.1 |
TiO2 | 0.77 | MnO | 0.11 |
Element | Content (%) | Element | Content (%) | Element | Content (%) |
---|---|---|---|---|---|
L.O.I | 10.02 | Na2O | 1.23 | Zn | 0.54 |
Al2O3 | 7.7 | SiO2 | 25.3 | Zr | 0.1 |
Fe2O3 | 6.12 | SO3 | 5.9 | Cu | 0.07 |
CaO | 23.7 | K2O | 1.81 | Cl | 0.21 |
MgO | 2.86 | P2O5 | 13.6 | Sr | 0.1 |
TiO2 | 0.77 | MnO | 0.11 |
3.1.2 XRD
3.2 Results of the Tests on Mortar
3.2.1 Flow Table
Mix design no | SSA (%) | Excess water | Slump (cm) |
---|---|---|---|
1 | 0 | 0 | 21.08 |
2 | 5 | 0 | 20.5 |
3 | 10 | 0 | 20.95 |
4 | 15 | 0 | 19.25 |
5 | 20 | 23 | 21.74 |
6 | 30 | 28 | 21.26 |
7 | 50 | 38 | 19.57 |
3.2.2 Compressive Strength
3.2.3 Pozzolanic Activity of SSA
3.3 Results of the Tests on Concrete
3.3.1 Appearance Change
3.3.2 Slump
Mix design No | SSA and SF (%) | Superplasticizers (gr) | Ratio of plasticizers to cement % | Slump (cm) |
---|---|---|---|---|
1 | 0% SSA | 0 | 0 | 11 |
2 | 5% SSA | 0 | 0 | 10 |
3 | 10% SSA | 0 | 0 | 10 |
4 | 15% SSA | 0 | 0 | 9 |
5 | 20% SSA | 50 | 0.33 | 9 |
6 | 30% SSA | 75 | 0.5 | 7 |
7 | 0% SSA + 10% SF | 0 | 0 | 9 |
8 | 10% SSA + 10% SF | 30 | 0.6 | 10 |
9 | 20% SSA + 10% SF | 45 | 0.9 | 11 |
10 | 30% SSA + 10% SF | 60 | 1.2 | 10 |
3.3.3 Permeability
3.3.4 Tensile Strength
3.3.5 Compressive Strength
3.3.5.1 Specimens Without Silica Fume
3.3.5.2 Specimens with Silica Fume
4 Conclusion
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- Adding SSA to the mortar specimens reduced the slump of the mixes.
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- As the percentage of SSA replacement in cement increased, the color of the specimens became darker.
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- Increasing the percentage of SSA replacement in cement resulted in a decrease in the permeability of the concrete. The rate of decline in permeability was more significant in the specimens with 10% SSA replacement compared to those with 5% replacement.
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- The average reduction in the 28-day tensile strength of the concrete for every 5% increase in SSA was 4.83%. On the other hand, the 28-day to 7-day tensile strength ratio showed the highest values at 10% and 30% SSA replacement.
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- Adding 10% SF to the control specimen increased compressive strength by 11.49%. However, higher amounts of SSA decreased compressive strength in both specimens with and without SF. Incorporating 10% SF mitigated the adverse impact of SSA on compressive strength by 4% compared to specimens without SF. The optimal balance in concrete compressive strength is likely achieved by combining 10% SF with 10% SSA.