Figure 1.

Figure 2.
![Results of compression tests conducted on 60×80 mm cylindrical specimens. a) The variability of compressive strength in time [26, 27] b) Plain mortar sample and c) cement-GO sample after compression test at the age of 14 days [26]](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64706f1783f1392090d69759/j_acee-2019-008_fig_002.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20251206%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251206T212421Z&X-Amz-Expires=3600&X-Amz-Signature=c3895831ef36bd5d423d7a73a1202bf5a0d9a3b3ee4255a405cbbcff6000d31b&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 3.
![Results of compression tests conducted on 60 x 120 mm cylindrical specimens.
a) Stress-strain curves and b) variability of Young’s modulus values under increasing load [27]](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64706f1783f1392090d69759/j_acee-2019-008_fig_003.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20251206%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251206T212421Z&X-Amz-Expires=3600&X-Amz-Signature=1453f466d9965cbc2d7a3c5138cb2c1213f0f530b81db348143ed9c031768024&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Results of the uniaxial cylindrical compressive strength and Young’s modulus tests at the age of 28 days [27]
| Sample | Parameters | ||||
|---|---|---|---|---|---|
| Force [kN] | Strength [MPa] | Average strength [MPa] (increase) | Young’s modulus [GPa] | Average Young’s modulus value [GPa] (increase) | |
| R | 88.65 | 31.25 | 32.12 (0%) | 30.61 | 30.10 (0%) |
| 95.69 | 33.84 | 28.74 | |||
| 87.20 | 30.74 | 27.16 | |||
| 101.12 | 35.76 | 32.75 | |||
| 81.74 | 28.91 | 31.24 | |||
| GO0.03 | 118.08 | 41.78 | 41.18 (28%) | 31.52 | 31.90 (6%) |
| 113.10 | 40.02 | 30.63 | |||
| 115.02 | 40.70 | 30.43 | |||
| 120.45 | 42.62 | 33.23 | |||
| 115.30 | 40.78 | 33.69 | |||
Results of the flexural and cubic compressive strength tests at the age of 28 days [26]
| Sample | Parameters | |||||
|---|---|---|---|---|---|---|
| Flexural strength | Compressive strength | |||||
| Force [kN] | Strength [MPa] | Average strength [MPa] (increase) | Force [kN] | Strength [MPa] | Average strength [MPa] (increase) | |
| R | 1.78 | 4.17 | 4.00 (0%) | 64.55 | 40.34 | 39.90 (0%) |
| 60.94 | 38.08 | |||||
| 1.75 | 4.10 | 62.10 | 38.81 | |||
| 64.91 | 40.57 | |||||
| 1.59 | 3.73 | 65.71 | 41.06 | |||
| 64.84 | 40.52 | |||||
| GO 0.03 | 1.74 | 4.07 | 4.52 (13%) | 80.81 | 50.50 | 49.00 (23%) |
| 79.94 | 49.96 | |||||
| 2.23 | 5.22 | 69.80 | 43.65 | |||
| 79.92 | 49.94 | |||||
| 1.82 | 4.26 | 80.21 | 50.13 | |||
| 79.69 | 49.80 | |||||
Chemical and physical properties of cement
| Average values | |
|---|---|
| Loss on ignition [%] | 2.99 |
| Insoluble residue [%] | 0.81 |
| SO3 content [%] | 3.20 |
| Cl- content [%] | 0.063 |
| Na2O content [%] | 0.75 |
| Start of setting time [min] | 217 |
| Compressive strength after 2 days [MPa] | 26.5 |
| Compressive strength after 28 days [MPa] | 51.4 |
| Stability of volume [mm] | 0.80 |
| Specific surface area [cm2/g] | 3416 |
Composition of fabricated cement mortars
| Sample | Components | ||||
|---|---|---|---|---|---|
| Cement [g] | Water for GO dispersion [g] | Remaining water [g] | Sand [g] | Graphene oxide [g] | |
| R | 3400 | 0 | 1700 | 10200 | 0 |
| GO0.03 | 3400 | 222 | 1478 | 10200 | 1.02 |