Polymer Cement Grouting Material
CBGM polymer cement grouting material is a cement-based grouting material primarily composed of high-strength cement, polycarboxylate superplasticizer, and multi-mineral materials as the main modifying components. It features excellent fluidity, micro-expansion, certain toughness, strong bonding strength with concrete, and corrosion resistance and durability. It is suitable for grouting repair of concrete cracks with widths greater than 3mm and external steel reinforcement.
| II. Performance Indicators |
Table 1 Performance Indicators of Polymer Cement Grouting Material
| No. | Test Item | Performance Indicator |
| 1 | Vertical Expansion Rate (%) | 3h | ≥0.10 |
| Difference between 4h and 3h | ≥0.020 |
| 2 | Fluidity (mm) | Initial Value | ≥380 |
| 30min Retention Value (%) | ≥90 |
| 3 | Compressive Strength (MPa) | 3d | ≥25 |
| 7d | ≥35 |
| 28d | ≥55 |
| 4 | Flexural Strength (MPa) | 7d | ≥5 |
| 28d | ≥8 |
| 5 | Splitting Tensile Strength (MPa) | 7d | ≥3 |
| 28d | ≥4 |
| 6 | Bleeding Rate (%) | 0 |
| 7 | Positive Tensile Bond Strength with Concrete (MPa) | 28d | ≥1.5, and cohesive failure in concrete |
| III. Construction Process |
1. Pre-treatment: Use compressed air to blow out dust and contaminants from concrete cracks.
2. Embed grouting pipes: Place a grouting pipe approximately every 500mm along the length of the crack.
3. Seal cracks: Use inorganic rapid-setting materials to completely seal the crack surface.
4. Pressure test: Seal the grouting pipes and conduct a water or air pressure test at 0.2~0.3MPa to check the sealing integrity. Ensure the concrete crack surface remains moist but without standing water inside the crack.
5. Mixing: The mass ratio for CBGM polymer cement grouting material is: polymer cement grouting material : water = 10 : (2.5~2.8). Use a forced-action mixer or a modified impact drill for mixing. The mixed slurry should have uniform color, no powder lumps, sedimentation, uneven coloring, or bleeding, and its fluidity should meet the grouting consistency requirements. The mixed grouting material should be used immediately to prevent setting.
6. Grouting: Load the mixed grouting material into a specialized pressure grouting tank and inject it continuously into the crack at a pressure of about 0.3MPa. For vertical cracks, grout from the bottom up one nozzle at a time, sealing each nozzle immediately after filling. During grouting, ensure air is expelled from the crack. The last grouting pipe serves as an exhaust vent and must not be blocked to avoid hindering air release.
7. Curing: After grouting, maintain water curing at the grouted area for at least 7 days.
