In fact, epoxy resin has good physical and chemical properties, it has good bonding strength with metal and non-metallic materials, good dielectric properties, good dimensional stability, high hardness, good flexibility, and is stable to alkali and most solvents. Therefore, it is widely used, do you know the resin crack treatment method?
1. Use a sander to polish the 5cm wide sides of the crack, and then clean the crack with acetone. The interface should be free of oil, dust, etc.
2. For shallow cracks with a depth of less than 5mm, soak the epoxy resin paste in a dilute solution, dry and fix, and then scrape off in batches. The ratio of the dilute resin solution is resin: thinner: curing agent 1:0.4:0.25, which can penetrate into the root of the crack. Its structure is strong and can fill cracks.
3. For cracks with a depth greater than 5mm, the grouting nozzle is buried in a depth of 30-50cm, and then the crack is closed with a resin cement with a width of not less than 5cm. One is to block shallow cracks, and the other is to prepare for grouting.
It is particularly important that the location of the hole of the pre-embedded grouting pipe should be determined according to factors such as the length, depth, direction, and shape of the concrete crack. Under normal circumstances, points should be selected at both ends of the crack and the empty and solid parts to ensure that the mud can reach each gap and play a role in strengthening and preventing cracks.
4. After the gas measurement is qualified, the resin slurry is used for pressure grouting, and the air pressure is not less than 4kg/cm~2.
5. After Jinan epoxy resin mortar is completely dry, conduct a gas tightness test to check the integrity of the slurry inlet, liquid outlet and crack seal. Pressure air of 4 kg/cm~2 is used for input from the grout hole.
If there is no leakage at the outlet of the cement, there is no leakage at the cement seal and other crack outlets, it means that the crack grouting port and outlet are set correctly, the cement seal is reliable, the outlet is closed, the pressure in the crack is increased to 4kg/cm~2, and the pressure is maintained for 2 minutes. If there are no leaks, this is normal. After the ventilation is increased, if there is air leakage in the cement, it should be closed again. If more than two liquid outlets are discharged after ventilation and pressure rise, it indicates that the crack is connected to more than two cracks. At this time, the leakage outlet should be closed until there is no leakage, and the record and mark should be made.
After the ventilation is boosted, there is no gas gushing out of the outlet, which may be caused by the crack channel blocked by the cement sealing process. At this time, the appropriate position of the crack in this section should be re-determined, and an outlet and grouting port should be added to ensure that the entire crack has in principle inlet, outlet, pressure holding and no leakage section.
5. Remove the grouting nozzle and level the resin cement extending from the concrete surface. Conclusion The crack repair project of Zhentou Bridge has been successfully completed after 20 days of construction. Through practical tests, the cracks repaired by the resin slurry can improve the strength of the arch ring.
6. When grouting, pay attention to observe the liquid outlet of the grouting nozzle. After confirming that the grout is full, close the outlet of the grout nozzle, increase the pressure to 4kg/cm~2, keep the pressure for at least 5 minutes, and wait for it to dry naturally. The natural drying time should be 72 hours.