What are the requirements for the strength of cement mortar and concrete floor coverings?

1, located in the lower part of the ground bedding trench, concealed pipe, etc. should be constructed first, to be completed before the ground bedding and cement mortar construction.

2, bedding concrete and surface layer of cement mortar test block group, according to each layer of building ground engineering should not be less than 1 group. When each layer of building ground project area more than 1000m2, each increase of 1000m2 to do 1 group of test blocks, less than 1000m2 calculated according to 1000m2; when changing the ratio, should also be produced accordingly the number of groups of test blocks.

3, bedding should be laid in a uniform and dense subsoil. Fill or soil structure is disturbed subsoil, should be compacted in layers, before the construction of bedding.

4, when the design is not specifically required, the thickness of concrete bedding shall not be less than 60mm, and its strength grade shall not be less than C10.

5, the smoothing of cement mortar shall be completed before the initial setting of cement mortar, and the calendering shall be completed before the final setting of cement mortar.

6, when pouring the concrete bedding layer and surface layer, should adopt the method of pounding and wiping. When the surface of the surface layer appears to urinate, can add dry cement and sand for spreading; the volume ratio of cement and sand should be 1:2 to 1:2.5, and should be smoothed and calendared.

7, the thickness of cement mortar layer should not be less than 20mm, the volume ratio of cement mortar should be 1:2 (cement: sand), its consistency should not be greater than 35mm, the strength level should not be less than M15.

8, cement mortar layer should not be less than the cement grade 525 #, and is strictly prohibited to mix different varieties of different grade of cement.

9, the cement mortar surface should not be cracked, peeling, pitting, sand, hollow drum, inverted flooding and water phenomena.

10, the flatness of the surface of each layer of the ground, should be 2m straightedge check: the surface of the bedding layer is allowed to deviate from 10mm; the surface layer is allowed to deviate from 4mm.

11, cement mortar ground should be set up longitudinal and transverse shrinkage joints: longitudinal shrinkage joints are suitable for the spacing of 3-6m, the spacing of transverse shrinkage joints is suitable for the spacing of 6-12m.

12, ground shrinkage joints of the practice: the concrete can be cast when prefabricated wood. When the concrete will be prefabricated wooden bar buried in the concrete, and take out before the final set; can also be used in the concrete to reach the strength of the saw to cut the seam. The width of the seam should be 5-20mm, and its depth should be 1/3 of the thickness of the bedding layer, and the seam should be filled with flexible filler materials such as grease or asphalt.

13, when the cement mortar layer with buried pipelines and other local thickness thinning, should be added a layer of steel wire mesh to deal with, in order to prevent the surface cracks.

14, in addition to the above submission requirements, should also comply with the relevant national standards, norms and industry regulations, in particular, the implementation of mandatory standards for engineering and construction.