There is a cavity at the top of the cast-in-place beam bottom plate support. How to fix it?

1) The treatment of concrete holes shall be studied by relevant units * * *, and a repair or reinforcement scheme shall be worked out, which can only be treated after approval.

2) Treatment method of general holes: chisel away the loose concrete and weak serous membrane around the holes, rinse them with pressurized water, erect the formwork with trays, spray water to fully moisten them, then carefully pour them in layers with semi-dry fine stone concrete with strength grade higher than that of the structure, tamp them hard and maintain them. The concrete protruding from the structural surface shall be chiseled away after reaching 50% strength, and the surface shall be polished with 1: 2 cement mortar.

3) For large and deep holes, after cleaning according to 2), bury grouting pipe and exhaust pipe inside, fill in clean gravel (particle size 10~20mm), plaster the surface with mortar or pour a thin layer of concrete, and then make it dense by cement pressure grouting.