(1) Before grouting, apply crack repair glue to seal up the holes and cracks leaking from the wall. Loose parts
should be removed before jointing and sealing, and the empty drum on muddy water wall should be removed and plastered and closed again.
(2) position and distance of grouting nozzle. At both ends of the crack, at the junction of horizontal joint and vertical joint, and at the corner of the crack, the mouth should be set, and the distance of the mouth should be about 2mm when the joint width is less than 1mm; When the seam width is 1~5mm, it is about 3mm; When the seam width is 5~15mm, it is about 5mm.
(3) Pressure grouting is the key process to reinforce wall cracks by grouting. Grouting sequence should be gradually poured from bottom to top or from one end to the other, and the order must not be reversed. Grouting pressure should vary depending on the thickness of cracks, usually .15~.2Mpa. Before grouting, pour the slurry into the grouting tank, cover the inlet and tighten it, check the pipe joints, open the air outlet valve of the air storage tank, push the slurry into the slurry conveying pipe with the help of compressed air, and then press it into the gap through the nozzle. Immediately after the adjacent nozzle overflows with slurry, plug it with a plug, then jam the slurry delivery pipe and pull it away from the nozzle, plug the grouting nozzle with a plug, plug the slurry delivery pipe into the original nozzle that has already overflowed with slurry, loosen the slurry delivery pipe and continue grouting, so as to grout hole by hole until the whole crack is filled. After grouting, the external wall surface should be cleaned in time, and the grouting tank and slurry conveying pipe should be cleaned. After the slurry solidifies, remove the nozzle and clean it for reuse. When grouting, the air storage tank should be next to the grouting tank, so as to adjust the air pressure at any time. The grouting tank should not be too far away from the crack, and the slurry conveying pipe should not be too long, so as to make contact and dialogue convenient and timely during grouting.
(4) Crack grouting material can also be used according to Table 2.
(5) When there are many cracks, the local steel mesh can be reinforced with cement mortar. Can the steel mesh be used? 6@1~3 (bidirectional) or? 4@1~2。 Fix it on the wall with concrete wedges or expansion bolts. The spacing between wedges or bolts is about 5mm, and the arrangement should be plum blossom. Before construction, wall plastering should be scraped clean, masonry should be wetted before plastering with cement mortar, and it should be maintained for at least 7d after plastering with cement mortar.