mac concealer Concrete floor cracks and fill crack

lin22307

Concrete floor cracks and fill cracks of the wall measures

Residential project is currently filled with concrete floor and walls of the cracks are quite common, is according to the data and the company's situation, the cast concrete floor and block walls filled with cracks and measures as follows, for everyone in the the work of reference.
A residential type of cast concrete floor
1. Longitudinal cracks: the buildings along the longitudinal direction of the cracks,[link widoczny dla zalogowanych], mostly in the skin under the plate, up and down through the individual.
2. Transverse cracks: in span 1 / 3 of the range, along the lateral direction of the cracks in buildings, mostly in the skin under the plate, up and down through the individual.
3. Corner cracks: the four corners of the room appeared inclined cracks, leather board majority.
4. Irregular cracks: the rules of distribution and to have no cracks.
5. Slabs horizontal root fracture: 30cm away from the bearings inside the cracks, in the panel skin.
6. Along the direction of embedded wire tube cracks.
Second, the reasons for the cracks in the floor
1. Design
1.1 small safety margin when designing the structure, reinforcement, or lack of smaller sections, so that after forming slab stiffness is poor, the overall deflection is too large, causing plate corner cracks.
1.2 design thickness is not enough to do without checking deflection, the overall deflection is too large, causing plate corner cracks.
1.3 Housing longer time is not set expansion joints, shrinkage cracks in the weak links. (American Concrete Institute's data suggest that concrete shrinkage and temperature deformation has two types of dry shrinkage contraction per 30.48m about 19mm. Deformation caused by temperature changes,[link widoczny dla zalogowanych], 37 ℃ of temperature change or extension of 19mm each contraction of around 30.48m. China was 40m-long slab that freezing produced by hardening of the longitudinal shrinkage was 8-20mm.)
1.4 foundation design handled properly, causing uneven settlement, so that the upper structure of additional stress, resulting in floor cracks.
1.5 floor two-way force, by way slabs reinforced, causing cracks.
2. Premixed concrete reasons
2.1 water-cement ratio large, large amount of cement.
2.2 retarder efficient use of excessive, before setting stones without sinking, resulting in shrinkage cracks Shen,[link widoczny dla zalogowanych], often occurred in the slab junction.
2.3 sand quality is bad, bad grading, mud volume, containing large amount of powder.
3, the construction causes
3.1 Conservation is not in place, the mandatory specifications of concrete curing water to cover and thatch, thatch now most do not cover,[link widoczny dla zalogowanych], can not guarantee regular water wet.
3.2 fast construction speed, the load early, especially the brick house floors, finished the day before pouring the floor, on the second day of bricks, take car, resulting in early damage of concrete.
During the cold winter when 3.3.
3.4 or template support early form removal system stiffness is not enough.
3.5 paste is too thick floating concrete surface, the surface strength is not enough.
3.6 bar during the construction of concrete floor covered by step bend, step down, thick layer of protection, capacity decreased.
Third, measures to prevent cracks in concrete floor
1. Design
1.1 in the use of small-diameter steel case, an appropriate increase in reinforcement ratio can improve the ultimate tensile strain of concrete.
1.2-way configuration corner negative reinforcement, one-way plates are equipped with four negative reinforcement.
1.3 reinforcement ratio in the same circumstances, the use of smaller diameter steel bar,[link widoczny dla zalogowanych], narrow bar spacing, can improve the crack resistance of cast plate.
2. The construction area
2.1 Cast attempt to set the expansion joints, expansion joint spacing of about 14m, or desirability of a residential building unit vertical length of the floor bearing in place, slit width 10mm, the middle software, materials, concrete off the reinforcement continued.
2.2 when the steel banding to ensure uniform spacing, the same position to ensure that negative reinforcement, concrete placement set when the horse Road, do not step on negative reinforcement.
2.3 by plate vibrators, wiping pressure to pay twice live, and the second wiping pressure before the final setting.
2.4 increase in the embedded steel mesh under-wire, embedded steel pipe as far as possible the direction of the force along the layout.
Add water by covering 2.5 methods of conservation, and water is covering the requirements of peremptory norms, the current most of us only watering, no cover, after pouring the water can not guarantee replenish dry, can not ensure the concrete is curing period continuous wet state, to achieve their conservation effect.
2.6 1.2MPa concrete may not reach the Master, but the early form removal, or demolition by early system, after form removal to maintain vertical support.
More articles related to topics：

insanity workout Foundation Pit high-rise building

[link widoczny dla zalogowanych]

mac beauty powder Subway tunnel support systems Nu

	Forum SIMSON JAWA ROMET (!!) Strona Główna -> Romet Komar	Wszystkie czasy w strefie EET (Europa)
Strona 1 z 1