Filling the Gap Created by the Super Cell Expansion after Testing with Grout
Downward Telltale tubes may be used as grouting pipes for post-testing grouting, and at least two pieces are require to produce differential pressure.
Procedures for grouting:
1. Pour clean water from one pre-buried downward telltale tube, when the clean water comes out from another downward telltale tube instead of muddy water, start to grout the gap.
2. The grout filling’s cement to water ratio should be 1:0.5 or 1:0.6, and mixed with 7% expansive agent and 1% water reducer. The cement grade should be No.Po425.
3. Start to pour grout from one telltale tube. When the fresh grout comes out from another telltale tube, seal the pipe, and then maintain pressure to pour the grout (Maintained pressure: 3~5MPa, maintain one hour suggested.) The amount of grout is around 0.5~1.5t (double control with pouring pressure and grout amount).
4. The strength of grout should be no less than the pile shaft’s stiffness. There should be a supervisor present all the times to record the amount of concrete.