Easy response, summary of 17 common problems in construction quality!




If it is found that it can not meet the requirements, it shall be returned in strict accordance with the regulations.



For the platform, the erection elevation of the formwork shall be controlled first to avoid the construction according to the elevation control line during concrete leveling, and the height of the formwork will affect the thickness of the protective layer.

During the waterproof construction of the bottom plate, the vertical edge of the pumping casing embedded with coiled materials in the sump shall be closed.

Before coiled material construction, the garbage and laitance on the surface of concrete base shall be cleaned, and the rough parts of individual surfaces shall be leveled with cement slurry.

The watering times per day shall be subject to ensuring that the concrete has sufficient wetting state, and the maintenance of vertical components shall be mainly controlled.

The commercial concrete station is required to adjust the construction mix proportion at any time according to the water content of sand and gravel.


The closure shall be pasted firmly, and it is strictly prohibited to have defects such as wrinkles, hollowing, blistering, slippage, edge warping, or lax sealing and closure.

Considering the slump loss according to the weather conditions, the concrete mix proportion shall be adjusted in time.

The thickness of the pouring layer is 1.25 times the length of the action part of the vibrator.

Simple on-site detection method: lay 1 m2 coiled material on the base course, and after drying in the sun for 2 hours, there is no water stain under the coiled material, which meets the requirements.

The thickness of the cushion block must meet the requirements of the thickness of the concrete protective layer, and the geometric dimension of the component after forming shall be controlled.

Additional layers shall be added at corners, pipes, construction joints, post cast strips, etc., and the width of the additional layer shall meet the requirements.

The lap length of the long and short sides of the coiled material shall not be less than 100mm and 150mm respectively.

Construction joints shall be set in strict accordance with the specification requirements.

The springboard must be laid for concrete pouring, and special personnel shall be arranged to watch the reinforcement.

Strengthen the spot check of concrete slump at the construction site.


During the concrete pouring of the bottom plate, the casing shall be sealed with expansion agent mixed with cement, then welded and sealed with steel plate, and finally poured with concrete.

Special transport vehicles shall be used for concrete transportation.

The horse stool shall be made of secondary steel with a diameter of 12, and the manufacturing size of the horse stool shall be strictly controlled.

Conduct random inspection on commercial concrete station together with the construction and supervision units from time to time, and make records.


If problems are found on site, timely report them in writing to the construction and supervision units for research and treatment, and conduct strength rebound on the pouring parts.







Strengthen the drainage and dewatering of foundation pit until the waterproof construction is completed and meets the waterproof construction requirements.


3、 The thickness of reinforcement protective layer is unqualified.

4、 The concrete strength grade cannot meet the design requirements.

Strictly control the moisture content of the base course during coiled material construction, which is required to be no more than 9%.


During the construction of post cast strip and construction joint, the water stop steel plate shall be embedded, and the vibration of this part shall be strengthened during concrete pouring.

After the waterproof coiled material construction is completed, the protective layer construction shall be carried out in time to avoid damage.


Technical disclosure shall be made to the commercial concrete station, and the strength grade, impermeability grade, slump, workability and other special requirements shall be described in detail.


The commercial concrete station is required to inspect the raw materials as required and put them into use only after they are qualified.

1、 Backfill subsidence 1.

The cushion block shall be placed at a spacing of about 1m and bound on the stressed reinforcement.



The vertical reinforcement adopts the cushion block embedded with iron wire, which is bound to the main reinforcement outside the reinforcement framework.

Cement and additives specified in the contract must be used.


The thickness of stressed reinforced concrete protective layer shall meet the design requirements.

When vibrating concrete, the vibrator shall be strictly prevented from hitting the reinforcement, resulting in loose buckle and displacement of cushion block.

When binding the upper reinforcement of the platform reinforcement, a full-length strip horse stool shall be set.


If there are no specific requirements in the design, it shall not be less than the diameter of stressed reinforcement and comply with the provisions of the current concrete quality acceptance code.

For vertical members, large steel formwork shall be adopted.


When pouring concrete, the free height of pouring, layered pouring, intermittent time and retention of construction joints shall be controlled: in order to avoid segregation of concrete, the height of concrete falling into the formwork from the discharge port, that is, the free falling height shall not exceed 2m.



Focus on ensuring the control of the protective layer of the negative moment reinforcement at the cantilevered parts such as the balcony.

Trapezoid Rubber Magnetic Chamfer

For the pouring of vertical components, the mortar shall be connected according to the regulations.

2、 Basement leakage 1.


2) During winter construction, the concrete components shall be covered according to the requirements of the construction scheme, and the grass curtain shall be laid for thermal insulation maintenance..


It is forbidden to add water on site, but it is allowed to add admixtures on site by technicians of commercial concrete station to control the slump of concrete under special circumstances.



Before backfilling earthwork, the rubber soil of the base shall be treated.

Generally, it can be covered and watered within 12h after pouring (for high-temperature season in summer, it is required to cover immediately after the second time of wood crab).

The steel wire mesh and wood strip in the construction joint shall be cleaned in time.

The concrete mix proportion of commercial concrete station shall be strictly controlled, and the mix proportion notice shall be provided for each concrete pouring.

Tamping and filling shall be carried out as required, and the compaction coefficient shall meet the design requirements.

Layered pouring shall be adopted for mass concrete and concrete wall.

It is strictly prohibited to pour the moistening pump mortar into one component.

Backfill earthwork must be paved and compacted in layers; The paving thickness and compaction times shall comply with the specifications.

In addition to binding cushion blocks as required, limit reinforcement shall be welded on the main reinforcement.


Strengthen the curing of concrete, ensure the normal growth of concrete strength and prevent cracks.



In the construction of impermeable concrete, corresponding measures shall be taken to avoid leakage.

For the sump, column base and other parts, a waterproof coiled material shall be added according to the requirements of the construction scheme.

During concrete construction, strengthen the vibration, strictly follow the requirements of “fast insertion and slow extraction”, and control the vibration time and radius of concrete.

When pouring the platform, put the moistening pump mortar into the hopper and lift it away with a tower crane.

After the concrete pouring is completed, it shall be roughened and cleaned, and the micro expansion concrete shall be poured in time for plugging after reaching the time specified in the design.


Raw materials meeting the design requirements and construction specifications shall be selected and put into use after passing the inspection.

During the construction of basement waterproof concrete, avoid ponding at the base, and it is strictly prohibited to have reinforcement or steel pipe penetrating the waterproof concrete components.

Strictly control the soil material and moisture content selected for backfill.

The individual protective layers that do not meet the requirements shall be adjusted in time.

Generally, the curing date of watering shall not be less than 7 days and nights; The concrete mixed with retarding admixture and impermeability requirements shall not be less than 14 days and nights.

Soil materials containing frozen soil blocks shall not be used for winter construction.

The treatment method can be: turn over and dry, and then tamp; Soil replacement: excavate the rubber soil, replace it with dry soil, or backfill graded sand and gravel; Dry soil, quicklime powder, broken brick and other materials with strong water absorption are mixed into rubber soil to absorb water in soil and reduce water content.

Flat plate vibrator is used for platform concrete pouring.


Earthwork backfilling shall be carried out after the external wall concrete reaches the strength grade required by the design to avoid damage to the external wall caused by extrusion.


After the platform reinforcement is bound, it is strictly forbidden to step on it.

The post cast strip shall be set in strict accordance with the requirements to avoid uneven settlement and cracks.

For the control of the reinforcement protective layer at the lower part of the girder of the transfer floor, the reinforcement head with a diameter of 25 coated with antirust paint is used to replace the mortar cushion block to prevent the cushion block from being crushed.

Curing of concrete: 1) after concrete pouring, the exposed surface shall be covered and protected.



Before construction, clear the snow, ice and garbage in the foundation pit.

The cushion block shall be made of 1:2 cement mortar, and the formed cushion block shall be carefully cured to ensure that the strength of the cushion block meets the requirements and will not be crushed by the reinforcement during use.

Apply cold primer oil as required to ensure the combination of coiled material and concrete.

In case of intermission, the maximum duration of intermission shall be determined according to the type of cement used, concrete strength and setting conditions.


Under normal circumstances, concrete pouring shall be carried out continuously.

Strengthen the construction control of impermeable concrete such as basement floor, exterior wall and roof, and vibrate strictly according to the requirements to ensure the compactness of concrete.

The joints of the upper and lower layers and two adjacent coiled materials shall be staggered, and the upper and lower layers shall not be paved vertically to each other.

Before the waterproof construction of coiled material, the internal and external corners shall be plastered into a fillet with a diameter of 5cm.

The spacing of horse stools meets the requirements, and the general spacing is 1m.


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