What causes honeycomb appears in concrete components, how to deal with a first class builder

Treatment of honeycomb phenomenon in concrete structure: slight honeycomb phenomenon can be smoothed and modified with cement slurry, if it is a serious honeycomb, large area of cavities, leakage and other phenomena, it needs to be chiseled and re-poured concrete.

1. Honeycomb. 1) The mixing ratio is not accurate, and the sand and gravel grading is not good;

2) Stirring unevenly;

3) template leakage;

4) Insufficient vibration or leakage vibration;

5) The concrete is too thick at one time, the layering is not clear, the concrete handover is not clear, and the vibration quality can not be mastered;

6) The free falling height exceeds the regulations, and the concrete is segregated and the stones are piled up;

7) The vibrator is damaged, or the power is cut off during the monitoring and the vibration leaks;

8) The vibration time is not sufficient, and the bubbles are not excluded.

2. Hemp noodles. 1) Same as "honeycomb" cause;

2) The template is not cleaned, or the mold is removed too early, and the template is sticky;

3) Uneven or missed brushing of the release agent;

4) The wooden mold is not watered and wet, and the concrete surface is dehydrated and powdered;

5) The pouring time is too long, and the ash hanging on the template is too much and is not cleaned in time, resulting in the surface layer is not compact;

6) The vibration time is not sufficient, and the bubbles are not excluded.

The main factors that determine the strength of concrete are the cement strength grade and water-cement ratio:

Cement is the active component in concrete, and its strength directly affects the strength of concrete. Under the same conditions of mix ratio, the higher the strength grade of the cement used, the higher the strength of the concrete made. When the same kind of cement (the same variety and strength grade) is used, the strength of the concrete is mainly determined by the water-cement ratio.

Because the binding water required during cement hydration, generally only accounts for about 23% of the cement mass, but when mixing concrete mixture, in order to obtain the necessary fluidity, often need to use more water (about 40%-70% of cement mass), that is, larger water-cement ratio. When the concrete is hardened, the excess water remains in the concrete to form blisters or evaporate to form pores, which greatly reduces the actual effective section of the concrete to resist the load, and may produce stress concentrations around the pores. Therefore, it can be considered that under the condition that cement strength grade is the same, the smaller the water-cement ratio, the higher the strength of cement stone, and the greater the adhesion force with aggregate, the strength of concrete is higher.

But if the water is added too little (the water-cement ratio is too small), the mixture is too dry and hard, under certain tamping molding conditions, can not guarantee the quality of watering, and more honeycomb, holes will appear in the concrete, and the strength will also decrease.

The cohesive force of cement stone and aggregate is also related to the surface condition of aggregate, the surface of gravel is rough, and the cohesive force is relatively large, and the pebble surface is smooth, and the cohesive force is relatively small. Therefore, under the condition that the cement strength grade and water-cement ratio are the same, the strength of crushed stone concrete is often higher than that of pebble concrete.

How to deal with honeycomb when the appearance of concrete engineering appears? What is the cause of honeycomb? The following is an introduction to the content of how to deal with the honeycomb in the appearance of the supermold concrete project brought by the construction network for reference.

First, the cause of honeycomb.

1) The mixing ratio is not accurate, and the sand and gravel grading is not good; Dig aside.

2) Stirring unevenly;

3) template leakage;

4) Insufficient vibration or leakage vibration;

5) The concrete is too thick at one time, the layering is not clear, the concrete handover is not clear, and the vibration quality can not be mastered;

6) The free falling height exceeds the macro rubber determination, concrete segregation, and stone piling;

7) The vibrator is damaged, or the power is cut off during the monitoring and the vibration leaks;

8) The vibration time is not sufficient, and the bubbles are not excluded.

1. The prevention and control measures are:

Strictly control the mix ratio, strictly measure, and check frequently;

Concrete mixing should be sufficient and uniform;

If the blanking height exceeds 2m, a string drum or chute should be used;

Layered blanking, layered tamping, to prevent vibration leakage;

Plug the gaps of the formwork, and check and correct the leakage at any time during pouring;

2. The treatment measures are:

For small honeycombs, 1:2 cement mortar is smoothed and compacted after washing;

Larger honeycomb, chisel off weak and loose particles, wash the formwork, and carefully fill and compact with fine stone concrete of a higher strength grade;

Deep honeycomb can be buried in the grouting pipe and exhaust pipe, the surface is plastered with mortar or poured concrete to close the cement grout.

After washing, smooth and compact with 1:2 or 1:2 5 cement mortar; Larger honeycomb, chisel off the weak and loose particles at the honeycomb, after brushing, use A3 durable high-strength repair material for careful filling and tamping, deep honeycomb, if it is difficult to remove, can be buried grouting pipe, exhaust pipe, surface plastering mortar or pouring concrete after closure, cement grouting treatment.

Carefully design, strictly control the concrete mix ratio, and check frequently, so that the measurement is accurate, the concrete is mixed evenly, and the slump is suitable; If the cutting height of concrete exceeds 2m, a string drum or chute should be set; Irrigation should be layered blanking, layered vibration, to prevent vibration leakage; The formwork joints should be tightly blocked, and the formwork support should be checked at any time to prevent slurry leakage during watering.

The phenomenon of concrete honeycomb is that the concrete structure is partially loose and has no strength. The reason for this is that the blanking is improper or the blanking is too high, and the string cylinder is not set to concentrate the stones, resulting in the segregation of the stone mortar;

The honeycomb phenomenon on the concrete wall refers to the appearance of a large number of different sizes on the concrete surface.

First, the depth is not.

1. Small pits with irregular spacing. This phenomenon will make the wall surface unsmooth and unsightly, and in severe cases, it will also affect the strength and durability of the concrete wall. Below, we will introduce the reasons for the honeycomb shape of concrete walls from two aspects: concrete materials and construction technology.

First, the problem of concrete materials.

1) The concrete mix ratio is unreasonable: the concrete mix ratio will directly affect the strength and compactness of the concrete, if the mix ratio is unreasonable, it will make the concrete surface irregular small holes.

2) Unqualified or uneven concrete materials: The quality of concrete materials is also a key factor affecting the flatness of concrete surfaces. If there are quality problems with the selected cement, aggregate and other materials, or if there are differences in the quality of materials in different batches, it will lead to honeycomb on the surface of the concrete.

Second, the construction process problems.

1) Vibration is not in place: Vibration is not in place is one of the main reasons for the honeycomb on the surface of concrete. When pouring concrete, if the vibration is not thorough, it will lead to insufficient density of the concrete surface and honeycomb.

2) Premature demoulding: concrete needs to be cured for sufficient time after pouring, otherwise it is easy to appear surface cracks and honeycombs. If the demoulding time is too early, that is, when the concrete is not fully cured, it will lead to the honeycomb shape of the concrete surface.

3) Improper construction environment: Concrete needs to maintain a suitable construction environment during the construction process, if the environment is too wet or too hot, it will lead to honeycomb on the surface of the concrete.

In general, there are various reasons for the honeycomb shape of concrete walls, which need to be comprehensively considered in the selection of concrete materials, the construction environment of concrete and the construction of Changlun technology, and make various preparations to avoid this problem.

Summary. The honeycomb shape of the poured foundation concrete is mainly due to concrete segregation or problems with the mix ratio. It will lead to the reduction of concrete strength, which will not reach the design strength, and affect the bearing capacity of the foundation, that is, the bearing capacity of the foundation will decrease.

The main reason for the honeycomb appearance of the poured foundation concrete is the concrete segregation or the problem of the ratio of the cover forest. It will lead to the reduction of the strong burning and dullness of the concrete, which will not reach the design strength, and affect the bearing capacity of the foundation, that is to say, the bearing capacity of the side foundation of the ground will decrease.

I hope mine can help you and have a great day!

It is not necessary to dismantle it from the new.

Yes. The decrease in bearing capacity can easily cause the road surface to collapse, which is a potential safety hazard.

After washing, smooth and compact with 1:2 or 1:2 5 cement sand code early slurry; Larger honeycomb, chisel off the weak and loose particles at the honeycomb, after brushing, use A3 durable high-strength repair material for careful filling and tamping, deep honeycomb, if it is difficult to remove, can be buried grouting pipe, exhaust pipe, surface plastering mortar or pouring concrete after closure, cement grouting treatment.

Carefully design, strictly control the grip ratio of concrete with old mold, and check it frequently to achieve accurate measurement, uniform concrete mixing, and suitable slump; If the cutting height of concrete exceeds 2m, a string drum or chute should be set; Irrigation should be layered blanking, layered vibration, to prevent vibration leakage; The formwork seam should be tightly blocked, and the formwork support should be checked at any time to prevent slurry leakage during the watering.

[Solution].

Small honeycombs to brush first.

After the source is clean, smooth and compact with BAI1:2 or 1:2:5 cement mortar;

The larger DU honeycomb is first chiseled to remove the weak scattered dao particles at the honeycomb after brushing and cleaning the formwork, and carefully filled and compacted with a higher grade of fine stone concrete, and the deeper honeycomb is difficult to remove, and the grouting pipe, exhaust pipe, surface mortar or pouring concrete are closed after being carried out.

Causes] honeycomb refers to the local looseness of the concrete structure, less mortar, more stones, and the formation of gaps between the stones similar to honeycomb-like holes.

The concrete mix ratio is improper, and the water addition of stones and cement materials is not allowed, resulting in less mortar and more stones.

The concrete mixing time is not enough, the end is mixed evenly, and the workability is poor, and the vibration is not compact.

Improper blanking or too high blanking, the end of the string is set to concentrate the stones, resulting in the separation of stones and mortar.

The concrete end is layered and unloaded, and the vibration is not real or the vibration leakage or the vibration time is not enough.

The gap of the formwork is not tight, and the cement slurry is lost.

The steel bar is dense, and the particle size of the stone used is too large or the slump is too large.

Shear walls, columns, and wall roots continue to be poured with a little intermittent intermittent pouring.

Treatment of honeycomb phenomenon in concrete structure: slight honeycomb phenomenon can be smoothed back with cement slurry, if.

It is a serious honeycomb answer, large-area cavities, leaking ribs and other phenomena need to be chiseled and re-poured concrete.

1. Honeycomb. 1) The mixing ratio is not accurate, and the sand and gravel grading is not good;

2) Stirring unevenly;

3) template leakage;

4) Insufficient vibration or leakage vibration;

5) The concrete is too thick at one time, the layering is not clear, the concrete handover is not clear, and the vibration quality can not be mastered;

6) The free falling height exceeds the regulations, and the concrete is segregated and the stones are piled up;

7) The vibrator is damaged, or the power is cut off during the monitoring and the vibration leaks;

8) The vibration time is not sufficient, and the bubbles are not excluded.

2. Hemp noodles. 1) Same as "honeycomb" cause;

2) The template is not cleaned, or the mold is removed too early, and the template is sticky;

3) Uneven or missed brushing of the release agent;

4) The wooden mold is not watered and wet, and the concrete surface is dehydrated and powdered;

5) The pouring time is too long, and the ash hanging on the template is too much and is not cleaned in time, resulting in the surface layer is not compact;

6) The vibration time is not sufficient, and the bubbles are not excluded.

Touch it with a cement surface and it won't be there.

The honeycomb of concrete is a common quality problem that is easy to occur in the construction of concrete engineering, and the main performance is that the concrete is locally loose, the mortar is less, the gravel is more, and the voids between the gravel are formed, forming honeycomb-shaped holes.

Measures to control the cellular phenomenon.

1) The mix ratio of concrete should be adjusted according to the construction situation of the concrete process, such as vibration mode, transportation mode, steel bar size and steel bar distribution, etc.; When it is found that the workability of concrete is not ideal, water should not be added only because this will damage the strength and durability of the concrete, but the mix ratio of concrete should be adjusted or the pouring method of concrete should be improved.

2) The unloading of concrete should be careful. In any case, when discharging concrete, it is important to pay attention to the key point of avoiding segregation. The concrete should be discharged vertically, and the closer the discharge port is to the final position, the better; Concrete should not flow to its designated position, and if it is necessary to move them, a large shovel should be used; After the unloading of a truck of concrete, the next truck should be carried out next to the tail of the previous place, rather than starting a new one, and finally connecting them, because this often produces a honeycomb phenomenon at the connection.

3) The formwork should have sufficient stiffness, stability and strength to avoid the displacement of the formwork when vibrating the concrete; The joints should be properly sealed to ensure that there is no slurry leakage.

4) Carefully carry out the vibration operation of concrete to avoid unreal and excessive vibration. The new layer of concrete should be vibrated in place at depth, and the distance between the vibrating points should ensure that each concrete is not missed.