Remedy concrete pouring 8 kinds of defects?

1, the phenomenon of common disease:

Pap is the surface of the concrete localized lack of paste rough or small pits, pockmarks, bubbles, etc., the formation of a rough surface, but the surface of the concrete is not the phenomenon of exposed steel.

2, the causes:

(1) the template surface rough or adhering to the hard cement paste scale and other debris is not cleaned up, demolding of the concrete surface is sticking bad;

(2) the template is not watered wet or not wet enough, the surface of the concrete components of the concrete moisture is absorbed, so that the concrete loss of water appeared in the pitting;

(3) template splicing joints are not tight, local leakage of pulp

(4) the template isolation agent is not uniformly painted, local leakage or failure, the concrete surface and template bonding caused by pitting;

(5) concrete vibration is not solid, the air bubbles are not discharged, resting on the surface of the template to form pitting.

3, preventive measures:

The template surface clean, shall not be adhered to the dry cement mortar and other debris; pouring concrete, the template watering fully wet, the template gap, with linoleum paper, putty and other blocking;

Choice of long-lasting template isolation agent: brush uniformly, shall not be omitted; the concrete layer by layer uniform vibration and compacting to exclude the air bubbles until.

4, processing methods:

Surface for painting, can not be dealt with, the surface is not painted, in the pitted parts of the water fully wet, with the original concrete with the stone mortar, will be smoothed and calendared pitted surface.

Two, concrete leakage treatment

1, the phenomenon of common disease:

Reinforced concrete structure of the main reinforcement, secondary tendons or hoop tendons, etc. exposed on the surface, not wrapped in concrete.

2, the causes:

(1) pouring concrete, rebar pad displacement, or pad leakage, resulting in rebar down or out of the tightly adhering to the surface of the exposed template;

(2) the concrete mix ratio is not appropriate, resulting in segregation, by the template parts of the lack of slurry or templates seriously exposed slurry;

(3) the protective layer of concrete is too small, or the protective layer of the concrete at the leakage of vibration, or the vibration bar impact on the steel bar or the vibrating rod, or the vibrating rod is not a good idea. Vibrating rod impact steel or step on the steel, so that the displacement of steel, resulting in the exposure of reinforcement;

(4) wood template is not watered and wet, absorbent bonding or demolding too early, demolding lack of prongs, corners, resulting in the exposure of reinforcing steel;

(5) aggregate particle size, vibration is not sufficient, the concrete in the reinforcement of the air-conditioning caused by the reinforcing bars and the template between the absence of concrete.

3, prevention and control measures:

Pouring concrete, to ensure that the location of reinforcing bars and the correct thickness of the protective layer, and strengthen the inspection; reinforcing bars are dense, the selection of the appropriate size of the stone, to ensure that the concrete ratio is accurate and have good compatibility;

Pouring height of more than 2m, the use of skewers or chute for the material to prevent segregation; the template is sufficiently wet and carefully plug the gaps; Concrete vibration is strictly prohibited to hit the rebar, in the rebar dense, can be used blade or vibrating rod vibration;

Operation, to avoid stepping on the rebar, such as stepping on the bend or buckle in time to straighten, correct and the protective layer of concrete to be vibrated compact; correctly grasp the time of demolding, to prevent premature dismantling of the mold, touching the bad edges and corners.

4, processing methods:

(1) on the surface of the exposed tendons, brushing dry, with 1:2 or 1:2.5 cement mortar will be exposed to the parts of the smoothing, and careful maintenance.

(2) If the exposed tendon is deeper, the weak concrete and prominent particles should be chiseled away, scrubbing clean, with a higher strength level than the original micro-expansion of fine stone concrete filling compaction, and careful maintenance.

Three, the treatment of concrete honeycomb

1, the phenomenon of common disease:

Honeycomb is the concrete structure of localized loose, aggregate concentration and no mortar, the formation of honeycomb-shaped holes between the aggregate.

2, the causes:

(1) improper concrete mix ratio, or sand, stone, cement materials plus water measurement is not allowed, resulting in less mortar, stone more.

(2) Concrete mixing time is not enough, not mixed evenly, poor compatibility, vibration is not dense.

(3) the material is not appropriate or the material is too high without a skewer to make the stone concentration, resulting in stone mortar segregation.

(4) the concrete is not layered under the material, vibration is not solid, or leakage of vibration, or vibration time is not enough.

(5) The gaps in the formwork are not plugged tightly, and the cement paste is lost.

(6) The reinforcement is dense, and the particle size of the stone used is too large or the slump is too small.

(7) The foundation, columns and wall roots continue to fill the upper layer of concrete without a slight interval, resulting in cement slurry loss.

3, prevention and control measures:

Conscientious design, strict control of the concrete ratio, frequent inspection, to achieve accurate measurement: concrete mixing, slump is suitable; concrete height of more than 2m set up a string or chute;

pouring of layered material, layered tamping to prevent leakage of vibration; formwork joints are blocked tightly in the pouring, at any time to check the template support to prevent leakage of slurry; foundation, columns, walls, walls, the wall of the upper layer without a break to continue to pour the loss of cement slurry. Leakage of slurry; foundation, columns, wall roots in the lower part of the watering intermittent 1 ~ 1.5h, solidified before pouring the upper part of the concrete, to avoid a "rotten neck".

4, treatment methods:

(1) for small honeycomb: first rinse with water, with 1:2 cement mortar repair; attention to maintenance, to be repaired after the mortar reaches a certain strength, the use of angle grinder sanding again; for higher requirements of the place can be sandpaper grinding.

(2) for the large honeycomb: first loose stones and prominent particles removed, and pick into a flare and chiseling, chiseling the base surface with a steel wire brush with high-pressure water cleaning, fully wet, so that the base surface to achieve a clean, solid, rough, moist requirements, and then use plain cement slurry to sweep the slurry sufficiently, and then support the mold mixed with an expansion agent with a high strength of a grade of concrete grout carefully and strongly filled! Pounding, and careful maintenance.

Four, the treatment of concrete holes

1, the phenomenon of common disease:

Reinforced concrete structure in the larger holes, or honeycomb is larger, reinforcing steel partially or completely exposed.

2, the causes:

(1) in the parts of the more dense reinforcement or reserved holes and buried pieces, the concrete under the material was shelved, and continued to pour the upper layer of concrete without vibration.

(2) Concrete segregation, mortar separation, stones into piles, serious run pulp and not vibration.

(3) the concrete is too much and too thick at one time, the material is too high, the vibrator can not vibrate, the formation of loose holes.

(4) The concrete is stuck when tools, wood, mud and other debris are dropped inside the concrete.

3, prevention and control measures:

In the reinforcing steel dense and complex parts, the use of high grade fine gravel concrete pouring, filled in the template, carefully layered vibration compact or with artificial pounding;

Preserve holes, both sides of the same time, the side of the material, plus the opening of the pouring mouth, to prevent leakage of vibration; sand and gravel mixed in the concrete of erectile soil blocks, templates and other sundry objects falling, timely removal of Clean.

4, processing methods:

First chisel away the loose part of the hole, so that it forms a regular shape; with a wire brush to remove the dust and debris in the damaged place; blowing with compressed air to clean the repair surface;

Water rinse the repair surface, so that the repair surface of the surrounding concrete is fully wetted; fill with high-strength grade of fine gravel concrete, vibration, compaction, smoothing.

Fifth, concrete gaps, interlayer treatment method

1, the phenomenon of common disease:

The existence of horizontal or vertical loose concrete in layers within the concrete.

2. Causes:

(1) Construction joints or deformation joints are filled with concrete without joint treatment, removal of surface cement film and loose stones, or removal of weak concrete layer and sufficient wetting.

(2) Construction joints are not cleared of debris such as sawdust, soil, bricks, etc. or are not cleaned up.

(3) The height of concrete pouring is too large, and there is no skewer, chute, resulting in segregation of concrete.

(4) the bottom of the intersection is not grouted joint mortar layer, joints at the concrete is not well vibration

3, prevention and control measures:

Conscientiously deal with the requirements of the construction joints and deformation joints on the surface; joints sawdust, soil, bricks and other debris cleaned up and washed; the height of the concrete is greater than 2m to set up a skewer or chute; test test plus Weixin 17691135285. Before pouring at the joints, pour 50 ~ 100mm thick original proportion of stone-free mortar, or 100 ~ 150mm thick half-stone concrete, in order to facilitate the combination of good, and strengthen the joints at the concrete vibration compact.

4, processing methods:

Seam inclusions are not deep, loose concrete can be chiseled away, scrubbed clean, with 1:2 or 1:2.5 cement mortar strong filling dense; click into the free experience of the test question bank. Seam entrapment deeper, remove the loose parts and internal inclusions, wash clean with pressurized water after supporting the mold, strong filling of fine stone concrete or the surface closed after grouting.

Six, concrete strength is not enough, poor homogeneity of the treatment

1, the phenomenon of common disease:

The same batch of compressive strength of concrete test block average value is lower than the design requirements of the strength level.

2, the causes:

(1) cement expired or damp, activity is reduced; sand and gravel aggregate grading is not good, large voids, large mud content, debris; additives are not used properly, inaccurate mixing amount

(2) improper concrete ratio, measurement is not permitted; construction of arbitrary addition of water, so that the water-cement ratio increases.

(3) Concrete addition order reversed, mixing time is not enough, mixing and uneven.

(4) winter construction, premature demolding or early freezing.

(5) Concrete test block production is not vibration dense, poor maintenance management, or maintenance conditions do not meet the requirements, in the same conditions of maintenance, early dehydration or smashed by external forces.

3, prevention and control measures:

Cement has a certificate of conformity, fresh, no lumps, expired cement by the test before use; sand, stone size, grading, mud content, etc. in line with the requirements; strict control of the concrete ratio to ensure that the measurement is accurate; concrete mixing in order to ensure that the mixing time and mixing;

Prevent the early freezing of the concrete, the construction of winter with ordinary cement! Preparation of concrete for winter construction with ordinary cement, strength of 30% or more, slag cement preparation of concrete, strength of 40 or more, can be subjected to freezing, according to the requirements of the construction regulations to seriously produce concrete test blocks, and strengthen the management and maintenance of test blocks.

4, processing measures:

When the concrete strength is low, available non-breakage methods (such as rebound meter method, ultrasonic method) to determine the actual strength of the structural concrete, such as still can not meet the requirements, according to the actual strength of the structure of the safety of the calibration, the study of the treatment program, to take the phase of reinforcing or reinforcing measures.

Seven, the concrete lack of angular treatment

1, the phenomenon of common disease:

beam, plate, column, wall and hole at right angles, the concrete partially fall, irregular, angular defects.

2. Causes:

(1)Wooden formwork is not wet or not wet enough before pouring concrete, the concrete is not well maintained after pouring, the moisture of concrete at the corners is absorbed by the formwork, resulting in the bad hydration of concrete, the strength is lowered, and the corners are glued off when the formwork is removed;

(2)When the construction is at room temperature, the side non-load-bearing formwork is removed too soon;

(3)When the formwork is removed, it is hit by external force or heavy objects. External force or heavy impact, or poor protection, the corners are touched off, resulting in missing corners.

3, prevention and control measures:

Wooden template in the pouring of concrete before fully wet, concrete pouring after careful watering and maintenance; demolition of the side of the non-load-bearing template, the concrete has a strength of more than 1.2MPa;

Demolding attention to the protection of the corners, to avoid too much force too fast; lifting templates, to prevent impact on the edges; transportation, will be the finished product of the corners of the grass bag and other materials to protect from damage. Protect the corners of the finished product with straw bags and other materials during transportation to avoid damage.

4, processing methods:

When the corner is missing, use steel wire brush to brush the net, flush with water to fully wet, use 1:2 cement mortar to make up for the correct.

On the larger missing corner, the concrete and the protruding aggregate particles are chiseled away, flushed with water and wet, and then support the mold with a higher level of micro-expansion of fine stone concrete to make up for the good, and careful maintenance.

Eight, concrete expansion, burst film treatment

1, the phenomenon of common disease:

concrete pouring and vibration process of the template bulging out, offset, burst or even collapse.

2, the causes:

(1) the template lateral support rigidity is not enough, the template is too thin strength is not enough, the clamping block support is not solid;

(2) the use of large flow of pumping concrete, a one-time pouring is too high, too fast.

3, prevention and control measures:

(1) template calculation in addition to the formula, to be adjusted according to the specific circumstances, because the template calculation of uncertainty factors, such as concrete slump, temperature, pouring speed, vibration methods are uncertain, the calculation should be given to consider.

(2) bolt, bolt breakage occurs more in the nut off, such as a bolt nut off failure, resulting in increased force around the bolt to break, in turn affecting more bolts, thus the occurrence of the overall burst mold, such a situation can be used double nuts, or recommended production of bolts with pins to prevent the nut from falling off.

(3) As the concrete lateral pressure is distributed in an inverted triangle, the tie rod should be set up in accordance with the principle of the lower density of the upper sparse, in order to alleviate the problem of insufficient number of template tie rod.

(4) The stability of formwork support, focusing on checking the stability of the force bar and longitudinal support.

(5) When pouring concrete, require uniform and symmetrical material, strictly control the pouring height, especially on both sides of the door and window opening templates, not only to ensure that the concrete vibration is dense, but also to prevent excessive vibration caused by deformation of the template.

(6) using wood templates, plywood templates construction, acceptance should be poured in a timely manner after acceptance, to prevent deformation caused by exposure to the rain. Repeated use of wooden templates must be strictly checked and repaired.

(7) Strictly require operators to control the insertion depth of concrete vibration, not too deep. Has been vibrating parts shall not be inserted again vibration cupping vibration, to avoid the phenomenon of mold bursting.

4, processing methods:

The deviation will be chiseled clean, rinsed with water, and fully wet, with the same ratio as the original ratio of the cement mortar to repair the correct.

When chiseling, do not cut off the reinforcement, such as must cut off the reinforcement, must be reported to the Engineering Department, Technical Department, Quality Assurance Department, and other relevant departments to study the treatment program, and then cut off the treatment, and careful maintenance.

If the concrete pouring process encounters the phenomenon of mold expansion, mold bursting, etc., must immediately stop the part of the pouring, in order to ensure the safety of the situation, immediately repair and reinforcement or according to the requirements of the program design and re-molding. And re-acceptance before continuing to pour.

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