Views: 0 Author: Site Editor Publish Time: 2024-11-25 Origin: Site
(Common schematic diagram of cement concrete foundation structure)
The newly poured concrete is required to have an overall curing period of no less than 28 days (water retention curing ≥ 7 days, dry curing drying ≥ 21 days) after the completion of the foundation.
The basic grade of building concrete should reach C25 or above, with a thickness of ≥ 10cm.
Use a hard small tool to scrape the scratch depth for strength inspection. The deeper the scratch, the lower the label and the poorer the strength.
Water testing: Using the fluidity of water, after watering the foundation, the observed water accumulation area is the more concave position.
Test: Use an aluminum alloy ruler or a pull wire (suitable for larger areas) to identify the recessed area.
Visible to the naked eye, it belongs to a relatively serious shell peeling situation;
When stepping on or knocking on the foundation and hearing a hollow sound, it indicates that there is peeling;
Only a thin layer of cement foundation (thickness<5cm) was laid on top of the original foundation, resulting in a higher probability of foundation shell formation in the later stage;
There may be later repairs to the roadside stones or ditch cover edges, and there is also a possibility of shell formation in the later stage.
Check if there are any cracks in the eyes;
Are expansion joints opened as required, and are there expansion joints on large areas of the site;
Understand the condition of the concrete foundation. If the foundation is soft or not compacted, there is a high possibility of foundation settlement.
On sunny days, lay a transparent film flat on the ground and seal it with tape around. After 2-4 hours, if there is fogging inside the thin wax, the ground moisture content is too high and construction is not suitable.
Heat the same point on the ground with a gas blowtorch. If there is a wheel ring phenomenon around the heating point, the ground moisture content is too high and construction is not suitable.
If the moisture content measured by a high-frequency moisture meter is above 8%, it is not suitable for construction.
For new cement foundations, first use test strips moistened with PH5-6 water (after warming the foundation, stick the test strips to the base surface). If the pH value is between 6.8-7.8, it is a weak alkaline foundation. Use 3% dilute hydrochloric acid or oxalic acid to scrub the site; If the pH value is between 7.8-10, use about 6% dilute hydrochloric acid or oxalic acid to scrub the site; A pH value greater than 10 is considered strong alkali and should not be used for construction, otherwise the adhesive surface will peel off due to alkali migration for a period of time.
| Project | Requirement | Rectification Plan |
| Planeness | The error of the 3-meter ruler shall not exceed 3 millimeters | Water grinder Partial repair |
| Drainage slope | 4‰-6‰ | Polish or redo the base surface |
| Basic strength | No sanding or powdering phenomenon Scratching hard objects without obvious sanding or powdering | Cement reinforcing agent Multi roll primer Grinding machine for polishing Redo the basics |
| Moisture content | Not exceeding 8% | Air drying Add drainage ditches Add asphalt |
| PH value | Alkali content not exceeding 10 | Dilute salt acid washing Water grinder polishing Add asphalt |
| Expansion joint | 6m*6m / 4m*6m Depth 2-3cm, width 1-2cm | Cutting seams Cut V-shaped groove |
| Drainage system | Surface drainage ditch depth 0.5-1 meter Width 15-30cm | Add drainage system |
The basic completion time shall not be less than 7 days for maintenance.
It is best to use modified asphalt for the basic grade (70 # is commonly chosen in the south, and 90 # is chosen in the north).
Use a hard small tool to scrape the scratch depth for strength inspection. The deeper the scratch, the lower the label and the poorer the strength.
Is there any unevenness or roughness in the asphalt foundation; After sealing the asphalt foundation, if the concave area is too large or the depth is too deep, it will cause high repair material costs, and in severe cases, it will lead to surface cracking.
The drainage ditch cover plate should be constructed strictly in accordance with the standards of the sports field, and special attention should be paid to the height difference between the ditch cover plate and the field.
| Project | Requirement | Rectification Plan |
| Planeness | The error of the 3-meter ruler shall not exceed 3 millimeters | Partial repair |
| Drainage slope | 4‰-8‰ | Redo the base surface |
| Compactness | 95% surface density | Redo the base surface Use a machine to compact |
| Thickness | 8cm (5cm coarse asphalt, 3cm fine asphalt) | Add asphalt |
Note: The quality of the plastic site foundation directly affects the usability and aesthetics of the site after completion. Therefore, the judgment of the foundation of the venue is particularly important, and taking different measures according to different foundation situations can create a perfect sports venue.
