1 Introduction
2 Experimental Procedures
2.1 Materials
Chemical analysis | Content (wt%) |
---|---|
CaO | 53.42 |
SiO2
| 19.48 |
Al2O3
| 4.69 |
SO3
| 4.08 |
MgO | 3.11 |
Fe2O3
| 3.04 |
K2O | 1.32 |
TiO2
| 0.38 |
P2O5
| 0.20 |
MnO | 0.13 |
ZnO | 0.11 |
2.2 Heat Treatment of Dredged Sea Soil
2.3 Pozzolanic Activity
Pozzolanic activity | Variation in conductivity |
---|---|
Non pozzolanic | Less than 0.4 |
Variable pozzolanic | Between 0.4 and 1.2 |
Good pozzolanic | Greater than 1.2 |
2.4 Compressive Strength
3 Results
3.1 Basic Properties of Dredged Sea Soil
3.1.1 Chemical Compositions
Chemical analysis (wt%) | Metakaolin | SH | JH |
---|---|---|---|
SiO2
| 56.96 | 53.50 | 65.07 |
Al2O3
| 35.65 | 12.68 | 13.30 |
SO3
| 0.23 | 3.57 | 5.54 |
Fe2O3
| 3.21 | 5.25 | 4.76 |
CaO | 1.81 | 12.80 | 2.13 |
Na2O | 0.51 | 2.97 | 2.96 |
MgO | 0.58 | 3.08 | 2.00 |
Cl | – | 2.32 | 1.56 |
P2O5
| – | 2.08 | 0.89 |
TiO2
| 0.31 | 0.46 | 0.52 |
CuO | – | 0.74 | 0.99 |
ZnO | – | 0.18 | 0.03 |
Cr2O3
| – | 0.12 | 0.17 |
MnO | 0.05 | 0.11 | – |
SrO | – | 0.07 | 0.05 |
Loss on ignition (%) | 3.3 | 8.0 | 6.2 |
3.1.2 Particle Size
3.1.3 Mineral Composition
3.1.4 Heat Treatment
3.2 Pozzolanic Activity
3.2.1 XRD
3.2.2 Electrical Conductivity
Type | Variation in electronic conductivity | Pozzolanic activity |
---|---|---|
SH at 500 °C | −1.37 | – |
SH at 730 °C | −1.41 | – |
JH at 420 °C | 0.62 | Variable pozzolanic |
JH at 500 °C | 1.26 | Good pozzolanic |
Metakaolin | 4.61 | Good pozzolanic |
3.2.3 TG/DTA
Plain cement paste | Metakaolin | Heat treated temperature | ||||
---|---|---|---|---|---|---|
SH at 500 °C | SH at 730 °C | JH at 420 °C | JH at 500 °C | |||
Weight before decomposition of CH (%) | 77.425 | 76.162 | 78.534 | 76.715 | 77.444 | 76.845 |
Weight after decomposition of CH (%) | 74.124 | 73.557 | 75.390 | 73.648 | 74.484 | 74.098 |
Amount of CH decomposition (%) | 3.301 | 2.605 | 3.144 | 3.067 | 2.960 | 2.747 |