Guangdong project Basement waterproof construction scheme
1) The pores, unevenness, honeycombs, gaps, sanding, etc. on the surface of the base course shall be leveled with cement mortar, filled and scraped with cement putty mixed with 15% 108 glue or polyvinyl acetate emulsion, and the base course must be clean, free of laitance, water drops, and water seepage. The flatness of the base course surface can be checked with a 2m guiding rule. The gap between the guiding rule and the base course is required to be ≤ 5mm. If it is exceeded, the surface shall be roughened, washed with clean water, and filled with cement paste, then trowelled with cement mortar; Dust, oil stain, rust, etc. on the surface of the base course shall be completely removed before waterproof coating. 2) The underground part of the project adopts support piles, which are connected by waist beams, and then an outer frame is erected between the support piles and the outer wall. The outer frame is the operating platform for waterproof operations. Therefore, before applying waterproof paint, the sundries on the outer frame, including the steel pipes left by the previous construction, should be removed first. 3) The tensile anchor bar protruding from the waist beam is generally large in length, and the longest one is only 5cm away from the side wall of the basement. Therefore, the reinforcement affecting the construction operation surface should be cut with an acetylene oxygen welder in advance. 4) There is also seepage water and splashing water on the maintenance pile on the site, which will have a negative impact on the quality of the coating film. Therefore, the site should guide the flow direction of the water source according to the actual situation, so as not to affect the normal progress of the waterproof operation. 5) The height between the lower part of the south waist beam and the pedal of the outer frame is only about 1350mm, and the width is only about 500mm. The actual construction is too difficult. The outer frame should be rectified to a reasonable height before construction. 6) Some remaining nails and binding wires on the outer wall must also be removed, and the holes left during cleaning shall be leveled with waterproof mortar. 7) Due to the needs of early construction, a small part of steel pipes are firmly jacked with the side wall. It needs to be removed in advance, and if any damage is found during removal, it needs to be cleaned and repaired with waterproof mortar. 8) Since the external wall of the project uses split screws, the small pieces of wood embedded in the split screws in the side wall should be chiseled out before the waterproof construction, and then the screw head should be cut off to the bottom of the hole left after the small pieces of wood are chiseled out with an acetylene oxygen welder, and then the hole should be cleaned, washed with clean water, and the hole should be filled with waterproof mortar. 9) Before coating construction, the internal and external corners of the base course should be in circular arc shape. The diameter of the internal corner should be greater than 50mm, and the diameter of the external corner should be greater than 10mm. 10) Before coating construction, internal and external corners, embedded parts, through walls and other parts shall be sealed or strengthened. 11) The preparation and construction of coatings must be carried out in strict accordance with the technical requirements of coatings. 12) In order to prevent the infiltration of groundwater and reduce the moisture permeability of the base course, a certain proportion of inorganic aluminum salt waterproof agent (cement: medium sand: inorganic aluminum salt waterproof agent: water=1:3:0.1:0.3~0.35) can be added to the cement mortar leveling layer to reduce the moisture content of the base course to below 9% and ensure the drying of the base course. The moisture content can be measured with a high-frequency moisture meter, or 1 ㎡ rubber sheet with a thickness of 1.5~2.0mm can be used to cover the surface of the base course for 2~3h. If there is no watermark on the surface of the covered base course, and there is no condensation watermark on the side of the rubber sheet close to the base course, the moisture content of the base course is not more than 9%. 13) During the waterproof construction of underground works, drainage shall be done well to reduce the underground water level to 300mm below the lowest elevation of the bottom of the membrane waterproof layer, so as to facilitate the full curing of waterproof coating. After the construction is completed, the drainage device can be removed and the drainage work can be completed only after the coating is completely cured and filmed; Four pumping points are set at the periphery of the site, with 25WQ8-22-1.1 submersible pumps for standby. 14) The coating construction should be carried out in sunny days with a temperature of 10~30 ℃. It should not be carried out in rainy days and strong winds above level 5, nor in foggy days. The ambient temperature for construction shall not be lower than 5 ℃, and fireworks are strictly prohibited during operation 15) Due to the complexity of the actual situation on the site, it is necessary to carefully patrol and check whether there are other factors affecting the waterproof operation before construction, and solve them according to the actual situation. 16) As there is a post cast strip in the project, but the actual post cast strip has not been cast on site, it is necessary to build a 120 brick wall three times the width of the post cast strip along the outside of the post cast strip, and then conduct waterproof operation. The post cast strip is a weak link, and additional coating layer must be added to enhance the coating, Then, the protective layer of the waterproof layer shall be well prepared, and then the subsequent construction of the post cast strip node shall be carried out according to the requirements in the general description of the structural design. See the attached figure for details of the node. 17) The treatment method for the crack on the concrete surface is: chisel the crack into a triangular groove 30mm wide and 30mm deep, and then trowel it with waterproof mortar. Then the waterproof coating application process is followed. 18) Before the roof waterproof coating is applied, the 24h water storage test shall be carried out first, then the leakage point shall be marked, and then the mark shall be strengthened.