Under what circumstances is secondary grouting used? Why is secondary grouting necessary?
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Under what circumstances is secondary grouting used? Why is secondary grouting necessary?
Use fine gravel concrete or cement slurry to fill the gap between the equipment base and the surface of the foundation and bury the pad iron in the concrete to fix the pad iron and bear the load of the equipment. The secondary grouting work should be carried out within 24 hours after the final leveling, alignment and concealment work of the machine has been inspected. Otherwise, the machine leveling and alignment data should be rechecked during grouting. The disadvantage is that the combination of cast-in-place concrete and the original foundation is not as strong as that poured in one go.
Secondary grouting is done when the equipment has not been completely completed and the position of the anchor bolts cannot be accurately determined, so a square position is left on the foundation. Grouting is done after the equipment is placed to ensure that the position is correct. (relatively narrow sense)
This reason should be explained by piping. The secondary grouting of reserved holes is suitable for horizontal vessels, heat exchangers, small vertical vessels and other stationary equipment and pumps with small vibration. The advantage is that it facilitates adjustment of the anchor bolt positioning size without defining a template. ； The disadvantage is that it is not stable enough. Therefore, direct buried anchor bolts are still used for towers, taller containers, and equipment with greater vibration.
For equipment and pumps that require anchor bolts, first leave reserved holes, then place the equipment base and grout twice.