1 Introduction
2 Experimental Investigation
2.1 Materials
Chemical composition | Typical results | SANS 50197-1 requirements |
---|---|---|
Insoluble residue: % by mass | 2.0 | 5.0 maximum |
Sulphur trioxide: % by mass | 2.0 | 4.0 maximum |
Loss on ignition: % by mass | 2.5 | 5.0 maximum |
Chlorides: % by mass | < 0.01 | 0.1 maximum |
physical properties | Typical results | SANS 50197-1 requirements |
---|---|---|
Setting times: | ||
Initial: minutes Final: hours | 125 2.5 | 45 minimum No requirement |
Specific area (Blaine): m2/kg | 400 | No requirement |
Compressive strength (mortar prism EN 196-1): | ||
At 2 days (MPa) At 28 days (MPa) | 28 ± 58 | ≥ 20.0 ≥ 52.5 no maximum |
Soundness: Le Chatelier Expansion (mm) | 1 | 10 maximum |
Densities: | ||
Relative density Bulk density, aerated, kg/m3 Bulk density, as packed, kg/m3 | ± 3.14 1100–1300 ± 1500 | |
Approximate volume: 50 kg bag, ℓ | ± 33 |
Chemical constituents | Percentage composition (%) |
---|---|
SiO2 Al2O3 Fe2O3 CaO MgO SO3 Na2O K2O CaCO3 LOI LSF SR AR | 65.10 5.32 7.25 10.56 2.75 1.62 1.04 3.36 4.37 5.18 1.23 4.43 6.96 |
Total SiO2 + Al2O3 + Fe2O3 | 77.67 |
2.2 Synthesis of Nano-TiO2
2.3 Preparation of Specimens
Sample number | Sample designation | Weight of cement (g) | Weight of WA (g) | Weight of NT (g) | Weight of water (g) | Water/binder ratio |
---|---|---|---|---|---|---|
1 | CEM 1 (control) | 500 | – | – | 180 | 0.36 |
2 | 90CEM1 + 10WA | 450 | 50 | – | 195 | 0.39 |
3 | 90CEM1 + 10WA + 1NT | 450 | 50 | 5 | 187 | 0.37 |
4 | 90CEM1 + 10WA + 2NT | 450 | 50 | 10 | 183 | 0.37 |
5 | 90CEM1 + 10WA + 3NT | 450 | 50 | 15 | 181 | 0.36 |
Sample code | Sample designation | Weight of cement (g) | Weight of WA (g) | Weight of SASS (g) | Weight of NT (g) | Weight of water (g) |
---|---|---|---|---|---|---|
A | CEM 1 + SASS (control) | 450 | – | 1350 | – | 225 |
B | 90CEM1 + 10WA + SASS | 405 | 45 | 1350 | – | 225 |
C | 90CEM1 + 10WA + 1NT + SASS | 405 | 45 | 1350 | 4.5 | 220.5 |
D | 90CEM1 + 10WA + 2NT + SASS | 405 | 45 | 1350 | 9.0 | 216 |
E | 90CEM1 + 10WA + 3NT + SASS | 405 | 45 | 1350 | 13.5 | 211.5 |
2.4 Testing of the Samples
3 Results and Discussion
3.1 Setting Times
3.2 Flexural Strength
3.3 Compressive Strength
3.4 Water Absorption
Specimen identification | Weight before immersion (g) | Weight after immersion (g) | Weight of water absorbed (g) | Percentage of water absorbed (%) | Average (%) |
---|---|---|---|---|---|
K1 K2 K3 | 525.2 526.9 526.9 | 557.5 558.2 559.4 | 32.3 31.3 32.5 | 6.2 5.9 6.2 | 6.1 |
L1 L2 L3 | 515.3 518.5 513.0 | 551.4 554.4 548.1 | 35.8 35.9 35.1 | 6.9 6.9 6.8 | 6.8 |
M1 M2 M3 | 507.7 508.1 511.4 | 540.8 541.7 545.3 | 33.1 33.6 33.9 | 6.5 6.6 6.6 | 6.6 |
N1 N2 N3 | 517.7 519.7 516.1 | 547.8 551.5 547.6 | 30.1 31.8 31.5 | 5.8 6.1 6.1 | 6.0 |
O1 O2 O3 | 512.0 520.7 518.3 | 543.6 553.0 551.1 | 31.6 32.3 32.8 | 6.2 6.2 6.3 | 6.2 |