How concrete foremen manage quality issues

For the on-site foreman, it is to accept the concrete, then the quality of the concrete itself is controlled by the laboratory, and you may need to direct the production of the specimen, if necessary, this test block must be taken seriously and do your best to do it.

On the spot, after the inspection is completed, when the concrete can be accepted, 1, must be prepared, whether the vibrating rod, generator, chute or crane pump truck is in place. 2. The pouring sequence process must be reasonable and well-founded, either there is a technical disclosure, or you have a certain experience. 3. Vibration is very important for you, not only to have a secret room, but also not to over-vibrate, but also to pay attention to the surface after molding.

This is the most important thing to do in the face. 4. In the process of pouring and vibrating, it is necessary to pay attention to whether the template is stable, whether there is a mold expansion, and whether there is any treatment experience and plan. 5. If you need to wipe the surface and collect the light, the calendering time is arranged and the order is arranged.

6. Watering and maintenance, I have done all my work, can't it crack in three days?

A little addition to the second floor:

1. Coordinate the concrete of the commercial concrete, control the interval between the concrete transport vehicles, and pay attention to the construction at night.

2. Review and arrange the strength grade of each car concrete, for example: in high-rise buildings, the concrete number of the column (C45) and the beam plate (C30) is different, and the pouring arrangement is different.

3. At the end of each concrete pouring, the measurement is carried out (the personnel of the commercial concrete station should also do this work), and the concrete is audited.

4. Most of the concrete pouring construction is carried out at night, so special attention should be paid to the safety of personnel in the construction process.

Slump vibrates how the surface.

The quality control of the concrete construction process is mainly controlled from the five aspects of "man, machine, material, method and environment": 1. First of all, the control of people, the construction foreman and quality inspector management of the project department must be in place, and secondly, the construction team must be skilled in technology, have a certain sense of responsibility, and ensure the quality of the project through the quality of work; 2. The control of mechanical equipment is mainly to ensure that the performance of the concrete vibrating equipment is good, and if it is on-site mixing concrete, it must also ensure that the mixer performs well; 3. The control of material quality, commercial concrete should control the collapse degree and workability of the incoming concrete, and check whether there is any segregation phenomenon when entering the site. On-site mixing should also control the quality of raw materials and the measurement of mix ratio.

4. For the control of construction methods, first of all, we must prepare a concrete pouring construction plan, and the construction team must carefully make a disclosure, and at the same time check the implementation of the program measures, find problems, and solve them in a timely manner. 5. Environmental control, mainly to control noise, especially night construction, do not touch the formwork, steel bars, etc., when vibrating, to reduce noise disturbance to the people. After the concrete pouring is completed, it is also necessary to pay attention to the early maintenance work, so as to avoid the formation of quality defects such as sand and cracking due to the rapid dehydration of the concrete surface.

The curing of ordinary concrete shall not be less than 7 days, and the curing of waterproof concrete shall not be less than 14 days.

Screening of raw materials.

1) Cement: Choose cement with stable quality. The cement strength, standard deviation and setting time were comprehensively considered, and the cement quality was evaluated by mathematical statistics.

2) Aggregate: pay attention to check the strength, gradation, particle size, mud content, mud content and needle flake of aggregate.

3) admixture: can be used for concrete admixture more, such as fly ash, mineral powder, etc., the current fly ash application is the most general, the selection of fly ash should choose a relatively fixed manufacturer, and as far as possible to choose the fly ash of large power plants, because its supply is sufficient, the quality fluctuation is small. The mineral admixture shall have quality certification documents, and shall be re-tested in accordance with the relevant regulations, and its dosage shall comply with the relevant provisions and be determined by testing.

4) Admixtures: Considering the adaptability of admixtures and cement, the stability of admixture quality and the quality assurance system of manufacturers.

Management of raw materials:

1) The quarry has good drainage facilities to avoid water accumulation at the bottom of the pile. Cement, fly ash and other powder silos have moisture-proof and moisture-proof measures.

2) Sand and stone are stacked separately according to varieties and specifications, and mixing materials is strictly prevented to avoid mixing or misuse.

3) All kinds of materials are clearly marked, especially cement, fly ash, admixture storage bin, the feed port is covered and locked, and managed by a special person to prevent the wrong material from being polluted.

Hello, what are some thoughts on common quality problems in cast-in-place concrete construction?

In the current construction project, the proportion of cast-in-place concrete is increasing, so from the construction preparation, construction organization and deployment, construction plan formulation, construction technology to quality control and treatment, etc., it is necessary to use modern scientific and technological means extensively and comprehensively, and the effective control and management of all aspects of construction is the key to prevent and control the common problems of concrete quality, and it is also an important link to ensure the quality of concrete engineering and improve the quality of construction engineering. They are the causes and treatment methods of honeycomb generation and the causes and treatment methods of honeycomb. Hope it helps, thank you.

The company's quality management is a system engineering; It is not a simple quality management position or an inspector who can do a good job in quality management; It is necessary to mobilize the resources of the whole company to continuously do improvement activities; Companies with no foundation in quality management can introduce the quality management system ISO9001:2015 for systematic quality management, and then introduce 50430 later.

A key link in concrete quality control.

Concrete quality control includes two basic contents: 1. Make the concrete meet the quality standards required by the design. 2. Try to reduce the cost under the premise of meeting the quality indicators of the design requirements, and these two requirements are actually to reduce the standard deviation of the concrete as much as possible.

The strength of concrete has a certain discreteness, which is objective, but it can be controlled to reach the minimum value through scientific management, so the standard deviation of concrete can reflect the actual management level of the construction unit, and the higher the management level, the smaller the standard deviation. It can be said that concrete quality control is essentially the control of standard deviation. In fact, the standard deviation should be controlled from the following aspects.

1) Design a reasonable concrete mix ratio. The reasonable concrete mix ratio is determined by the laboratory through experiments, and in addition to meeting the requirements of certainty, durability and saving raw materials, it should have the workability of construction requirements. Therefore, in order to design a reasonable ratio in the laboratory, qualified cement, sand and stone must be provided.

Cement control strength, sand control fineness, moisture content, mud content, etc., stone control moisture content and mud content, etc. Only when the material meets the qualified requirements, can a reasonable concrete mix ratio be made, so that the construction can be carried out normally and reasonably, and the design and acceptance standards can be met.

2) Construct correctly according to the design mix ratio. According to the construction mix ratio, the moisture content of sand and stone should be measured in time, and the design mix ratio should be converted into the construction mix ratio. Secondly, to use the weight ratio, not the volume ratio, finally, to check whether the raw materials are consistent with the design of the raw materials, which requires the supplier to provide two copies of the same material, one to the laboratory, one to the construction site, the site receiving personnel should be according to the sample receiving, if the incoming material and the sample do not match, should be reported to the superior immediately, timely change the mix ratio (except for the material is not qualified).

3) Strengthen the management of raw materials, the variation of concrete materials will affect the strength of concrete. Therefore, the receiving personnel should strictly control the quality, do not allow unqualified products to enter the site, and report in time if they are inconsistent with the raw materials, and take corresponding measures to ensure the quality of concrete.

4) For the determination of concrete strength, we take the strength of 28 days as the standard, for the simplicity of construction and quality assurance, we generally do 7 days of test blocks, etc., in order to measure the development of concrete strength as far as possible according to its age, so as to clearly determine its quality.

To sum up, we should control the quality of concrete from all aspects to ensure the quality of the whole project to ensure the credibility and development of the enterprise.

The key to this is to have a good team!

Quality assurance measures for concrete works.

1. Commercial concrete is divided into different situations and different parts to make technical disclosures to commercial concrete manufacturers.

2. Concrete pouring: the structure is poured first column and then beam plate. The continuous pouring of the beam and plate is completed at one time, and the intermittent time for eating in the middle is not more than 40 minutes. When pouring the wall columns, the layers (within 50cm) vibrate and compact.

3. Concrete construction joints: floor construction joints, which are left in the parts of the structure that are less sheared. The following provisions should be observed when continuing to pour and pound the construction joints:

1) The compressive strength of the poured concrete should be greater than.

2) On the hardened concrete surface, the cement film and loose stones or weak concrete layers should be removed, and fully moistened and rinsed without water accumulation.

3) Before pouring, the construction joints should be covered with cement slurry or a layer of cement mortar with the same composition as the concrete for grouting.

4. The concrete should be carefully tamped so that the new and old concrete are tightly combined.

5. When the mud content of sand and stone exceeds the specified level, it must be washed.

6. The mix ratio of concrete composition materials should be used according to the data provided by the laboratory. When the material changes, the test mix ratio should be done in time: when the water content of sand and stone changes, it should be adjusted in time according to the actual situation.

All kinds of materials should be weighed accurately, and should not be converted by volume ratio. The measurement error is strictly controlled within the allowable range.

7. In order to prevent the change of slump and the loss of cement slurry, the transportation materials must be tight and do not leak water and slurry. And in use, the concrete residue hard block is often removed.

8. Before pouring concrete, the debris in the formwork must be removed, and the surface of the steel mold must be put on the demoulding oil before each turnover before using the formwork. The vibrating tamping concrete is used, and the vibration time of each point is appropriate to vibrate the concrete to the surface to show floating slurry and no longer settle. The upper layer of concrete is inserted into the vibrator before the initial setting of the lower layer, and direct contact with the steel bar should be avoided.

9. Concrete curing: In order to ensure the quality of concrete, we must do a good job in curing, when the concrete is finally set, before hardening, start to carry out sprinkling curing, pay attention to the water flow can not directly pour the concrete surface, should make the water flow spray in the form of fog. When the concrete strength is reached, lay a layer of straw bales, and regularly sprinkle water on the straw bales to keep the concrete surface of the floor slab wet.

Before the concrete is strong, people cannot trample on the concrete. Watering and maintenance should not be less than 14 days in summer and not less than 7 days in winter. When the roof is removed, the concrete strength must reach 75% of the design number, and attention should be paid not to damage the concrete surface when removing the formwork.

10. In the process of pouring concrete, the concrete test block must be carefully done according to the requirements of the specification and according to each team and quantity. Concrete test blocks must be randomly sampled on site and cured according to standards.