Concrete Floor Hollowing, Cracking

Preventive and curative measures.

Strictly treat the substrate (bedding or base layer). First, carefully clean the surface of floating dust, slurry film and other dirt, and rinse clean. If the surface of the concrete floor is too smooth, it should be chiseled. The second is to control the flatness of the grass-roots level, the convexity should not be greater than 10mm, to ensure uniform thickness of the surface layer, to prevent the thickness is too large, resulting in uneven shrinkage and cracks, hollow drums when the condensation hardening. Third, 1 day ~ 2 days before the surface layer construction, should be the grass-roots level watering wetting, so that the grass-roots level has a clean, wet, rough surface.

Strictly control the combined layer construction quality. (2) strictly control the quality of the combined layer construction. The combined layer of plain cement paste should be evenly painted after grouting, and it is strictly forbidden to use the method of sweeping the paste after sprinkling the dry cement surface and pouring water. The water-cement ratio of plain cement slurry should be 0.4~5. The brushing plain cement paste should be closely matched with the paving surface layer, so that it can be paved with the brush. When laying the surface layer, if the plain cement paste has been air-dried and hardened, it should be removed and repainted.

Concrete Floor Hollowing, Cracking

Ensure the construction quality of the concrete pad. The concrete pad should be vibrated by plate vibrator, and the unevenness should be leveled by cement mortar or fine stone concrete.

Transverse grid joints according to the size of the axis; longitudinal grid joints spacing ≤ 6m (transverse total length between the two axes equally divided).

Concrete ground, cement mortar to reach the design strength of 50% ~ 70% of the timely sawing joints, requiring straight stitches, cutting the width and depth of the saw joints to meet the requirements.

The basement floor proposed to use the original slurry ground compaction smoothing technology.

Strengthen the maintenance of the floor ground.

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