What do you need to pay attention to in the process of beating concrete?

First, the operation process:

1. Process flow:

Cleaning at the bottom of the tank or in the formwork, concrete mixing, concrete pouring, concrete vibration, concrete curing.

2. Cleanup: Remove silt and debris on the foundation or foundation soil, and there should be waterproof and drainage measures. For dry soil, water should be moistened, and no stagnant water should be left on the surface. Remove garbage, soil and other debris in the slab of the formwork, and water the wet wood formwork to block the seams and holes of the slab.

3. Concrete mixing: the background should be carefully fed according to the mix ratio of concrete; The feeding order of each plate is stones.

Cement, sand (admixture), water (admixture). Strictly control the water consumption, stir evenly, and the shortest time is not less than 90 seconds.

4. Pouring of concrete:

1) The height of the concrete discharge port from the surface of the poured concrete shall not exceed 2 meters. If the free fall exceeds 2 meters, a string barrel or chute should be used.

2) The pouring of concrete should be carried out continuously in layers, and the thickness of the layers is generally times the length of the acting part of the vibrator. The maximum is not more than 50.

3) The plug-in vibrator should be plugged in quickly and slowly, and the insertion points should be evenly arranged, moved point by point, and carried out in order, without omission, and the technology should be dense with vibrator. The spacing between the movements shall not be greater than the times of the radius of the vibrator. Vibrating the upper layer is that the lower layer 5 should be inserted to eliminate the seam between the two layers.

The spacing of the plate vibrator should be such that the plate of the vibrator covers the vibrated edge.

4) When the concrete cannot be poured continuously, it generally exceeds 2 hours, and it should be treated according to the construction joint.

5) When pouring concrete, you should always pay attention to observe whether the formwork, support, pipeline reserved hole, and embedded parts are moving. When deformation and displacement are found, the pouring should be stopped immediately, and dealt with in time before continuing to pour.

6) After the concrete is vibrated and compacted, the surface should be smoothed with a trowel.

7) Concrete curing: After the concrete is poured, it should be covered and watered within 12 hours, and the watering times should be able to keep the concrete in a sufficiently wet state. The curing period is generally not less than 7 days and nights.

8) During the rain and winter construction, the seasonal construction plan should be prepared for the open-air pouring concrete, and effective measures should be taken to ensure the quality of the concrete.

Second, the quality problems that should be paid attention to:

1. The coagulation is not compact, and there is a honeycomb surface: mainly due to poor vibration, vibration leakage, inaccurate mixing ratio or slurry leakage in the gap of the template.

2. The surface is uneven, the elevation is not accurate, and the size is increased: due to the inaccurate line or wooden peg of the horizontal mark, the operation is not carefully leveled, or the formwork is not firmly supported.

3. Slag inclusion in the joints: the concrete at the construction joints is not well combined and there are sundries. It is mainly caused by not cleaning up carefully.

4. Irregular cracks: the foundation is too long and shrinks, the upper and lower layers of concrete are not well combined, the maintenance is not enough, or the mold is removed too early.

1. Clean up

Before pouring, the garbage, soil, oil stains and other debris on the steel bar in the formwork should be removed, and the cement mortar cushion block and plastic cushion block of the steel bar should be checked to see if they are well mated.

2. Concrete mixing

1. Determine the amount of various materials in each plate according to the mix ratio, and the moisture content of the aggregate should be measured frequently and adjust the water consumption of the mix ratio in time.

2. Loading sequence: generally pour stones first, then fill cement, and finally pour sand.

3. Concrete transportation

When pumping concrete, it is necessary to ensure that the concrete pump works continuously, if there is a failure, the stop time is more than 45 minutes or the concrete is segregated, the remaining concrete in the pipe should be washed immediately with pressurized water or other methods.

Precautions

Preparation before construction:

1. Be familiar with the drawings and clarify the number and quantity of concrete.

2. Clarify the types of concrete and the restrictions of construction conditions on concrete: qualified steel bar testing, qualified formwork and support system inspection, qualified outer frame, temperature, humidity.

3. Formulate prevention methods for common problems in concrete construction and treatment methods for concrete construction problems.

4. Do a good job in the retention plan of the concrete test block, including the retention plan of the standard maintenance test block, the retention time of the test block under the same conditions, and the number of groups. The actual maintenance method, the inspection conditions of the test block.

5. Understand the ways and procedures for dealing with concrete problems.

The strength grade of structural concrete must meet the design requirements.

The total time of concrete transportation, pouring and intermittent should not exceed the initial setting time of concrete. The concrete of the same construction section should be poured continuously, and the previous layer of concrete should be poured before the initial setting of the bottom concrete.

The position of the construction joint should be determined according to the design requirements and the construction technical scheme before the concrete is poured. The treatment of construction joints should be carried out according to the construction technical plan.

The retention position of the post-pouring belt should be determined according to the design requirements and the construction technical scheme. The concrete pouring of the post-pouring belt should be carried out according to the construction technical plan.

After the concrete is poured, effective maintenance measures should be taken in a timely manner according to the construction technical plan, and should comply with the specifications.

Concrete pouring can be carried out after the formwork, steel bars and embedded pipelines are accepted. Wet the formwork first, and then start pouring, paying attention to the mix ratio and slump of the concrete. Vibrate while discharging, vibrate in a timely manner, do not leak vibration, otherwise there will be quality problems (honeycomb, hemp surface and other appearance quality problems), and the later maintenance should also keep up.

In this way, the quality of the concrete can be ensured.

What do I need to pay attention to when pouring concrete?

Preparation before concrete pouring.

(1) Before pouring concrete, the stability of the formwork support must be checked, and special attention should be paid to checking the stability of the formwork of the cantilever member supported by the diagonal brace. In the process of pouring concrete, it is necessary to pay attention to the observation of the formwork and support, find abnormalities, and report them in time.

2) Reserved openings next to the horizontal transportation channel, and the elevator shaft must be inspected and improved with cover plates and fences. The high place in the air must be stable, the fence railing on both sides, when the cart or motorized dump truck pours the concrete, there should be a gear measure, not too fierce or scattered.

3) When the derrick and gantry are used for vertical transportation, the handlebar of the trolley is not allowed to exceed the hanging plate, and the wheels should be blocked before and after. When the tower crane hopper is poured and pounded concrete, the command, the bucket personnel and the tower crane driver should cooperate closely, when the hopper is put down, the operator should avoid, stand steady, and it is strictly forbidden to pull the hanging objects and hooks by hand in the air.

4) The power cord of the vibrator must be intact, the power supply cable shall not have joints, and the wire of the motor shall be maintained with sufficient length and looseness when the concrete vibrator operation is transferred. It is strictly forbidden to drag the vibrator with a power cord. Workers must wear insulated rubber shoes and insulated gloves.

5) The barrel and groove used in pouring concrete must be fixed firmly, and the use of string cylinders should be firmly connected between the nodes, and the operation part is set up with a protective railing, and it is strictly forbidden to stand on the bucket and groove to operate.

6) When transporting concrete with a pump, the joint of the conveying pipeline must be tight and reliable, the safety valve must be intact, the pipeline frame is firm, and the pressure must be relieved during maintenance.

7) When pouring frame, beam and column concrete, an operating platform must be set up, and it is strictly forbidden to stand on the template or support to operate.

8) Scaffolding must be erected for pouring ring beams, awnings and balcony concrete, and it is strictly forbidden to stand on the wall or formwork to operate.

9) The pouring of the arch structure should be carried out symmetrically from both sides of the arch feet. When pouring the storage silo, the lower mouth should be closed first, and scaffolding should be erected to prevent personnel from falling.

10) When pouring at night, there must be sufficient lighting equipment.

The precautions when pouring concrete are as follows:

1. When the pouring height is greater than 2m, the string cylinder should be used, and the free height of the falling from the discharge nozzle to the pouring layer shall not be greater.

2. The concrete must be poured within 5 hours (from the time of departure), in order to prevent the concrete pouring from cold joints (cold joints: refers to the construction quality joints formed by the pouring time interval of the upper and lower layers of concrete exceeding the initial setting time), the two concrete pouring times do not exceed the hour, and the junction is stirred continuously with a vibrating rod.

3. During the pouring process, the vibration duration should make the concrete surface produce floating slurry, no bubbles, and no sinking. The insertion points of the vibrator are evenly arranged in the shape of plum blossoms, and the sequence of the determinant movement is adopted, and the distance of the moving position should not be more than 40cm. Ensure that there is no vibration leakage, but no vibration.

4. When pouring the beam and slab concrete, pour the beam concrete first, start from the beam and column node parts, ensure that the beam and column node parts are vibrated and compact, and pour them together with the plate in the cycle of the slurry method, but there shall be no cold joints.

5. After the concrete surface is pressed twice and three times, it should be covered and raised in time. After the concrete is finally set, sprinkle water first and fully moisten it, seal and cover it with plastic film, and check the surface of the plastic film frequently, but when there are no water droplets on the surface of the film, water should be sprinkled again.

The curing time of the roof from the 3rd basement to the underground mezzanine is 7 days, and the curing time of the roof of the 1st underground floor is 14 days.

6. After the concrete surface is pressed twice and wiped three times, it should be covered and maintained in time. After the concrete is finally set, sprinkle water first and fully moisten it, seal and cover it with plastic film, and check the surface of the plastic film frequently, but when there are no water droplets on the surface of the film, water should be sprinkled again. The curing time of the roof from the 3rd basement to the underground mezzanine is 7 days, and the curing time of the roof of the 1st underground floor is 14 days.

Precautions

1. Honeycomb: The reason is that the concrete is too thick at one time, and the vibration is not solid or leakage; There are gaps in the inner plate of the mold, and the cement slurry capacity is lost; The steel bar is dense and the concrete slump is too small or the stone is too large; The lower steps at the root of the foundation, column, and wall continue to pour the upper layer of concrete without stopping after pouring, so that the mortar at the root of the upper layer of concrete gushes out from the lower part.

2. Exposed ribs: The reason is that the displacement of the reinforcement cushion block, the spacing is too large, the leakage, and the exposed reinforcement is close to the template or the bottom of the beam and plate is not vibrating.

3. Matte surface: the surface of the formwork is not smooth or the formwork is not wet enough, and the concrete on the surface of the component is easy to adhere to the formwork, resulting in peeling and hemp surface.

4. Holes: The reason is that the concrete is stuck in the denser part of the steel bar, and the upper layer of concrete is continued to be poured without vibration.

5. Gaps and interlayers: Gaps and interlayers caused by unclean debris at construction joints or unpoured bottom slurry.

6. The cross-sectional size deviation at the beam and column nodes is too large: the main reason is that the stiffness of the column joint template is too poor.

7. The surface smoothing deviation of the cast-in-place floor slab and the staircase is too large: the reason is that the surface is not carefully smoothed with a trowel after the concrete is poured.

BIM technical disclosure for standard layer structure construction "Concrete pouring precautions and specification requirements".

1. When playing concrete, you need to pay attention to the weather. In the pouring process, in case of heavy rain and heavy rain, the incoming bucket material should be stopped immediately, and the concrete that has been put into the warehouse should be vibrated and compacted and covered. After the rain, the water in the warehouse must be eliminated first, and the parts washed by the rain should be treated immediately, if the concrete can be reshaped, the joint concrete should be paved and continue to be poured, otherwise it should be treated according to the construction joint.

Keep abreast of the weather forecast and arrange construction reasonably.

2. Concrete, referred to as:"Concrete (tóng).": refers to the general term of engineering composite materials that cement aggregates into a whole by cementitious materials. The word concrete usually refers to the use of cement as cementitious material, sand and stone as aggregates; Cement concrete, also known as ordinary concrete, is widely used in civil engineering engineering when it is combined with water (can contain external rot bush additives and admixtures) in a certain proportion and is mixed to obtain cement concrete, also known as ordinary concrete.