What causes cracks in the floor slab? How do I fix it?

Floor cracking in construction engineering is a common quality problem, is very common, there are cracks we have to deal with, the following is based on practical experience to summarize a few points for you, I hope to help you: analysis of the causes of floor cracking and treatment methods.

1. Analysis of the causes of cast-in-situ floor slab cracking:

1) Too much or too large embedded line pipe in the floor slab leads to the weakening of the concrete surface (in general: insufficient protective layer, thermal expansion and contraction of concrete.

causing cracking);

2) After the concrete is poured and smashed, the improper smoothing and calendering make the concrete surface appear too much slurry, and the hydration heat shrinks the board surface.

cracks will occur;

3) After the final setting of concrete, there is no timely watering and curing (covering film), resulting in the formation of temperature difference between the surface and the interior of the concrete and cracks;

4) If the slab concrete does not meet the design strength requirements, the formwork will be dismantled, resulting in the sinking of the concrete slab surface (or the load will be applied before the concrete reaches the final setting time.

causing cracking);

5) Negative reinforcement of the plate surface in the process of concrete pouring.

Bent by stepping (rebar protective layer.

too thin) leads to cracks in the board surface;

2. Technical measures to prevent cast-in-place floor cracking:

1) The embedded line pipe should be firmly tied with the steel bar on the plate (to prevent the concrete from being deviated), and the line pipe should not be too concentrated and embedded (the concrete pouring will not be in place, especially prone to holes and cracks);

2) After the initial setting of concrete, cover the board surface with film in time to prevent sun exposure (or use straw bags and sawdust for insulation);

3) Do not increase the load on the floor slab or remove the formwork too early;

4) If the strength of the floor slab does not meet the design requirements, the materials shall not be stacked in a centralized manner to prevent cracking;

5) When pouring the concrete of the floor slab, send a special person to protect the reinforcement to avoid stepping on the negative reinforcement of the bending slab surface;

3. Treatment of floor slab cracking.

1) General crack treatment, cleaning, with fine stone concrete.

Just apply it once;

2) If there is cracking before the final setting, it can be treated with plastering;

3) For the treatment of general cracks, clean the cracks around them, and then use cement mortar.

Wipe the seams, flatten and maintain;

4) If the crack is large, it will rain on a rainy day.

If water seepage occurs, the method of high-pressure grouting can be used.

It is very likely that the secondary wiping time is unreasonable, and there is no trowel to compact and level. It can be wiped with cement, and then compacted and leveled with a light machine.

It may be caused by concrete shrinkage, uneven force, or too high temperature; When repairing, you can use the same color of beauty sewing agent to repair, or you can remove all the floor slabs and choose other materials with better quality for repair.

This situation may be caused by a problem with the quality of the construction, you can fill the crack with cement mortar, and then scrape putty, so that it is not visible.

Content from user: zhangjidong437

Crack treatment scheme for floor slabs.

In the process of self-inspection and collection of concrete structures, it was found that some floor slabs on a few floors had cracks on the top and bottom of the slabs. According to the specific causes of cracks, the corresponding treatment plan is proposed.

1. Causes of cracks.

1. The water-cement ratio and collapse of concrete are too large.

The concrete strength value is very sensitive to the change of water-cement ratio, which is basically the superposition of the influence of water and cement measurement changes on the strength. Therefore, the measurement deviation of water, cement, mixed materials and admixture solutions will directly affect the strength of concrete. Pumping concrete in order to meet the pumping conditions:

The slump is large, the fluidity is good, and it is easy to produce the phenomenon of less local coarse aggregate and more mortar, at this time, when the concrete is dehydrated and dried up, surface cracks will be generated.

2. The concrete construction is too vibrating, and the formwork is too dry.

After the concrete is poured and vibrate, the coarse aggregate settles and extrudes the water and air, and the surface presents water secretion and forms a vertical volume reduction and settlement, resulting in the surface mortar layer, which has a greater dry shrinkage performance than the lower layer of concrete, and after the water evaporates, it is easy to form condensation cracks. And the formwork does not sprinkle enough water between the pouring concrete, and it is too dry, the formwork absorbs a large amount of water, which causes the plastic shrinkage of the concrete and produces cracks.

3. Improper maintenance.

Improper maintenance is also the main cause of cracks in cast-in-place concrete slabs. Premature curing can affect the cementing ability of concrete. Too late curing, due to the wind and sun, the free water on the surface of the concrete slab evaporates too quickly, and the cement lacks the necessary hydration water, and produces a sharp volume contraction, and the early strength of the concrete is low, and it can not resist this stress and produce cracking.

Especially in summer and winter, due to the high temperature of day and night, improper maintenance is most likely to produce temperature difference cracks.

Third, the treatment method of the bottom of the plate.

It is treated separately according to the exposed ribs and non-exposed ribs.

Summary. 1. Caused by the shrinkage of the concrete of the house.

If the cracking of the floor slab is caused by the concrete of the house, the surface is generally a penetrating crack, and water seepage may occur in the cracks. In general, such cracks are relatively common. If a 45-degree oblique crack is formed in the corner of the house, although such a crack has no impact on the safety of the house, it will greatly reduce the service life of the house.

2. The building is caused by temperature due to improper maintenance in the early stage of construction.

In the early stage of construction, if the construction is not only improper, but also improper maintenance, it will also cause cracks in the house. And the cracks in this type of house are generally spider web-shaped. Because such cracks are dense, they can lead to a decrease in the material quality of the concrete, which affects the bearing capacity of the house.

What are the causes of cracks in the floor slab after a few years of construction?

1. If the cracking of the floor slab caused by the concrete of the house is caused by the concrete of the house, the surface is generally a penetrating crack, and the phenomenon of water seepage may occur in the cracks. In general, such cracks are relatively common. If a 45-degree oblique crack is formed in the corner of the house, although such a crack has no impact on the safety of the house, it will greatly reduce the service life of the house.

2. In the early stage of construction, due to improper maintenance, the temperature is caused by the early stage of construction, if the construction is not only improper maintenance, but also will cause cracks in the house. And the cracks in this type of house are generally spider web-shaped. Because such cracks are dense, they can lead to a decrease in the material quality of the concrete, which affects the bearing capacity of the house.

If there are no other questions, please give a thumbs up, thank you.

I wish you a happy life and good health.

Summary. What are the causes of cracks in the floor slab after a few years of construction? Hello dear, concrete cracks are now a big problem in the engineering industry.

There are many factors that cause cracks in concrete, and there are dozens. The general floor cracks are mainly because of the plastic shrinkage cracking in the concrete forming process, mainly related to the surface water loss rate of concrete, and a good part is because the early load is too large, the template is deformed, the vibration is not compact, the slump is too large, and the water is added on the spot.

What are the causes of cracks in the floor slab after a few years of construction? Hello dear, concrete cracks are now a big problem in the engineering industry. There are many factors that cause cracks in concrete, and there are dozens of them.

The general floor cracks are mainly because of the plastic shrinkage cracking in the concrete forming process, mainly related to the surface water loss rate of concrete, and part of it is because of the early load is too large, the template is deformed, the vibration is not compact, the slump is too large, and the influence of factors such as water addition on the site of the mausoleum type.

It's been about 3 years, and it just happened recently this year.

Three-year-old house roof on the slag cracks, generally can be divided into stressed cracks and non-stressed cracks. 1. The stress crack is caused by factors such as uneven settlement of the foundation, concrete strength, and plate thickness; 2. Non-stressed cracks are caused by factors such as temperature, concrete shrinkage, construction, etc., and it appears early and late. Early shrinkage cracks appear about 2 to 4 hours after pouring is completed, and some temperature cracks do not appear until three months to six months after completion acceptance.

Among them, the main construction factors are the large protective layer of the negative reinforcement of the slab (serious collapse of the steel bar), the insufficient protective layer of the concrete at the bottom of the slab or the excessive chloride salt content of the sand. For the cracks on the surface of the general concrete floor slab, the cracks can be cleaned first, and then the joints can be filled with epoxy resin solution or sealed with surface painting after drying. If cracks are found before the final setting in the construction of oranges, they can be treated with plastering.

Many people will have cracks in the walls and floors of the house after living for a period of time, or find cracks in the floor slab when they accept the house, these cracks are likely to cause water leakage and other problems, and more serious will endanger the safety of the building.

1. What is the cause of cracks in the floor slab?

1. Irregular cracking: the concrete water-cement ratio is too large or the coarse and fine aggregate gradation is poor, the secondary wiping time is not in line with the basic finches, and the trowel is not used for compaction and leveling.

2. Regular cracks on the beam side: the negative moment reinforcement of the beam surface is not enough or the steel bar is stepped on early, resulting in the excessive protective layer of the negative reinforcement.

3. Oblique cracks at the corners of the floor slab: no radioactive reinforcing steel bars are set at the outer corner of the end of the room, and the floor slab is stressed too early, too heavy or too dense.

4. Penetrating cracks: the mix ratio and materials do not meet the requirements, or water is added on site, resulting in excessive slump, excessive pile load, premature mold removal, and poor maintenance. The low early strength of concrete is due to dry shrinkage during hydration and curing.

5. Cracking along the embedded pipe: the diameter of the embedded pipe is too large or the thickness of the floor is too thin, or the placement position is unreasonable, and it is not placed in the middle of the floor.

6. Cracks around the holes of the embedded box: the holes of the construction floor are not embedded round holes or the holes are too large, and no steel bars are set around the holes.

7. Cracking along the main reinforcement of the slab: the bottom reinforcement and the gluten protective layer of the floor slab are too small, and the vertical distribution of the reinforcement protective layer is too large or there is no distribution of reinforcement, resulting in micro-cracks in the reinforcement part.

Second, how to repair the cracks in the floor slab.

1. Do a good job of roof insulation: cracks caused by temperature changes are difficult to repair, but there will be no danger such as house collapse. In order to avoid such cracks, it is necessary to solve the problem by solving the linear expansion difference between the roof and the brick wall.

A common method is to do a good job of roof insulation. Due to cracks caused by insufficient stiffness of masonry, brick walls will undergo planar bending, and horizontal cracks tend to appear at the midpoint of the bending length. In this case, reinforcement measures should be taken.

Pure cement slurry can be injected into the cracks by pressure grouting, and then pilasters or walls between windows can be reinforced.

2. Repair after the settlement is stable: the cracks are usually caused by the uneven settlement of the foundation, and their location and square direction are different from the cracks caused by the insufficient strength and stiffness of the wall column. In other words, the cracks caused by the uneven settlement of the foundation do not cause problems with the strength or stiffness of the wall columns, and should be repaired with cement mortar after the settlement is stabilized.

The above is all about what causes cracks in the floor slab, how to repair the cracks in the floor slab, I hope to help you understand the repair of cracks in the floor slab, more decoration knowledge, decoration company evaluation, decoration cases, please continue to pay attention!

Summary. The reason why cracks in the floor slab are normal is that they can be remedied, and after treatment, they can still be considered qualified after plugging the joints. After all, the load-bearing requirements of the floor slab are small, and the design has a high insurance factor, even if there is a little problem, it can still ensure safety and will not collapse.

Is it normal for cracks to appear in the floor slab? Why.

Hello, I am helping you to inquire about the relevant information and will reply to you immediately.

The reason why cracks in the floor slab are normal is that they can be remedied, and they can still be qualified after they are plugged or violently. After all, the load-bearing requirements of the floor slab are small, and there is a high insurance coefficient when designing, even if there is a problem with the old age, it can still ensure that the safety code group is upgraded and will not collapse.

The abstract is not normal. Cracks in the floor slab are a common quality problem at present. In the face of this situation, you should report the situation to the developer in time, or apply to the quality supervision station where the house is located to conduct a quality inspection of the house, and ask for a written report.

Is it normal for cracks to appear in the floor slab? Why.

Hello, I have seen your problem and is sorting it out for you, please wait!

Abnormal. Cracks in the floor slab are a common quality problem at present. In the face of this situation, you should report the situation to the developer in time, or apply to the quality supervision station where the house is located to conduct a quality inspection of the house, and ask for a written report.

The living room is meters wide. There are 7 north-south longitudinal and horizontal seams on the right side, is this normal, there are also in the room, what is the reason for this.

It may be that the floor slab itself has a quality problem.

A bucket of water was poured upstairs, and it leaked downstairs immediately.

You should report the situation to the developer in time, or to the quality supervision station where the house is located.

Collect relevant supporting information.

Cast-in-place, this kind of problem should not occur, find the developer, he said that it is normal cracks to appear in this situation what is the best solution.

You look for the Quality Supervision Agency.

Negotiate compensation, and if you can't do it, you can appeal.

Can this house still be seated?

It is best to conduct a safety qualification.