Construction Method Of Silica Fume For Grouting

1. The mixing equipment, grouting equipment, template and maintenance items should be prepared before grouting construction.

2. During secondary grouting, the horizontal distance between the template and the equipment base should be controlled at about 100mm; the elevation of the top of the template should not be less than 50mm on the upper surface of the equipment base.

3. When the concrete structure is reconstructed and strengthened, sufficient grouting holes and vent holes should be reserved for the formwork support. The grouting hole diameter should not be less than 50mm and the spacing should not exceed 1000mm.

4. When mixing cement-based grouting materials, add water according to the required water consumption of the product. It is advisable to use mechanical mixing. When mixing, it is advisable to add 2/3 of the water and mix for about 3 minutes, and then add the remaining water and mix until uniform. The mixing location should be close to the grouting location.

5. Anchor grouting for anchor bolts:

⑴ When the anchor bolt is formed into a hole, the bolt hole wall is rough, the hole should be cleaned up, and there should be no impurities such as floating dust, oil, etc., soak in water for 8-12h before grouting to remove the inflammation in the hole.

⑵ Before grouting, the oil and rust on the surface of the anchor bolts should be removed.

⑶ When pouring the mixed cement-based grouting material into the bolt hole, the position of the bolt can be adjusted as needed. Vibration is strictly forbidden during the grouting process, and it can be properly inserted and the bolts shall not be adjusted again after grouting.

6. Secondary grouting of equipment foundation:

⑴ Before grouting, the equipment bottom plate and the surface of the concrete foundation that are in contact with the grouting material should be cleaned up, and there should be no loose gravel, floating slurry, floating ash, oil, wax, etc. 24h before grouting, the surface of the foundation concrete should be fully wetted, and 1h before grouting, remove the accumulated water.

⑵ During the secondary grouting, grouting should be carried out from one side until overflow from the other side, and grouting should not be carried out from opposite sides at the same time. After the grouting starts, it must be carried out continuously and the grouting time should be shortened as much as possible.

⑶ When the track foundation or grouting distance is long, the construction can be carried out in stages depending on the actual engineering situation, and the length of each section should not exceed 5 meters. If the equipment floor has a complicated structure, pressure grouting should be used.

⑷ Vibration is strictly prohibited during the grouting process. If necessary, a grouting booster can be used. The booster pushes the grouting material along the bottom of the flow direction of the slurry, and it is strictly prohibited to push from the middle and upper part of the grouting layer.

⑸ After the equipment foundation is grouted, it is advisable to cut a 45° bevel along the edge of the bottom plate after the initial setting of the grout. If trimming is not possible, use a spatula to calender the surface of the grout layer after the initial setting.

7. Concrete structure reconstruction and reinforcement grouting:

⑴ The concrete surface contacted by cement-based grouting materials should be fully chipped.

⑵ When repairing concrete structural defects, the loose concrete should be removed and the steel bars should be exposed, and the edge of the repaired area should be cut into a vertical shape.

⑶ All gravel, dust or other debris should be removed before grouting, and the surface of the base concrete should be wetted.

⑷ Pour the evenly mixed grout into the template and tap the template appropriately.

⑸ When the thickness of the grouting layer is greater than 150mm, relevant measures should be taken to prevent temperature cracks.

8. Construction maintenance measures:

⑴ When grouting, the uniform temperature of Riping should not be lower than 5℃. After grouting, the exposed part should be sprayed with curing agent or covered with plastic film, and covered with a wet grass bag to keep it moist. When using plastic film to cover, the exposed surface of cement-based grouting material should be covered tightly to keep condensation water in the plastic film. When it is inconvenient to water the grout surface, spray curing agent.

⑵ The grouting material should be kept in a moist state, and the curing time should not be less than 7 days.

⑶ When using fast-setting and fast-hardening cement-based grouting materials, the maintenance measures should be implemented according to the method required by the product.

⑷ In winter construction, when the project has no special requirements for strength growth, the exposed parts should be covered with plastic film and covered with insulation materials in time after grouting. The initial curing temperature should not be lower than 5°C. Do not water during curing under negative temperature conditions.

⑸ When the difference between the surface temperature of the cement-based grouting material and the ambient temperature after the mold is removed is greater than 20℃, the insulation material should be used for covering and curing.

⑹ If the ambient temperature is lower than the minimum construction temperature required by the cement-based grouting material or the strength growth needs to be accelerated, the artificial heating maintenance method can be used. The maintenance measures should meet the relevant regulations of the current national standard "Construction Regulations for Winter Construction" JGJ104.