The quality of the project, the masters who understand it help to answer

First of all, I want to say that you have to understand your position, you are not construction, you are only responsible for testing, as long as the report is made according to the facts, even if something really happens can not find you, of course, if you want to collect some bribes to unqualified also appear on the test report in the form of qualified, you still listen to the analysis of the first two.

The first question: Be careful, drill into the core of the sample.

The second question: rest assured, now the design of the floor slab protective layer has been mentioned 20 mm, if according to this standard, 25 mm then does not exceed the allowable deviation of the specification, so no problem.

The third question: How many do you think are really qualified for reinforcement planting?

I'm coming to the landlord's question: It's been almost 9 years since I graduated!

1. There is no problem, the design value of the axial compressive strength of C35 is 15MPa (this value is the psychological bottom line, just understand it yourself); There isn't much harm; (The landlord said that 32MPa is considered before or after carbonization, it is best to find some phenolphthalein to titrate it yourself, and it is best to do the technology 5 years before entering the industry).

2. The protective layer is too large, which is easy to cause cracks (the higher the grade of concrete, the more attention should be paid to); It is very dangerous to be too small, because the biggest role of the protective layer of the steel bar is not to prevent rust but to ensure the grip and wrapping force of the steel bar and the concrete (however, the existence of stirrups and the minimum protective layer are enough, so there is no need to consider it);

3. The quality of the planting tendon has no effect on the usual, but when it works! For wall cracking, fart doesn't work!

Digression: 1. This is your bookish anger that has not been worn out. Don't doubt leadership (especially those over 40 years old who have been in your profession for more than 10 years); Proper bookishness is precious, you can use him as motivation, not impulsive stupidity;

2. You will be like this if you stay up for 10 years!

3. Don't quit! You've only been working for two years and you can't do it (I suggest you go read the book "The Water of the Waves"). However, the construction is very tiring and the supervision is a lot of miscellaneous things; It is more comfortable to be Party A, but everyone has a scripture that is difficult to read!

Hehe, just be your little brother, add me balls, and I don't add Liu Jiusi (need to indicate to ask friends) without saying his identity!!

Despise replica doors.

In other words, these are all unspoken rules, and you can't do it alone. Anyway, it's still a problem.

1.Why does this kind of engineering exist and still pass acceptance? Refer to the first line of this article.

Solve a security concern you are worried about. The standards of each design institute are different, but the coefficients are very high, and the safety factor of the design institute in the key parts may be many times greater than the theoretical calculation intensity, and some are more than 5 times (because the design institute is also afraid that the engineering accident will be investigated to its own head, so the safety factor is as large as possible). If you don't believe me, you can look for the design specs.

2.The functions of the protective layer are, first, to ensure that the stressed steel bar is completely wrapped by concrete, so that it can work together; The second is to protect the stressed steel bars from erosion.

If the protective layer is within the range you say, it is nothing at all in construction. In the design code, there are different protective layers for different structures and different concrete strengths, and the general gap is about 1-2cm, in fact, the gap is difficult to grasp in construction. In addition, the protective layer of 15mm, in the construction, needs a very high level of construction, otherwise it is easy to leak the reinforcement, and the harm of the leakage reinforcement is greater, and it is not excluded that the construction unit has consciously increased the construction error to avoid the worst situation of leaking reinforcement.

3.If it is a frame structure, it is not a load-bearing structure for the masonry itself, and it will not have an impact on the safety of the main structure.

About the digression:

1.It's still an unspoken rule, this can't be helped. You can't change society, then you can only adapt to society. And you can't hide from it, there are unspoken rules everywhere. Isn't it the same with the Minister of Railways?

2.Who told you not to be a leader? I didn't watch the news, but a few of the people who went in were full-time.

3.As long as the income is good, just go on, just know how to protect yourself. It's not clear if it's fine. Let's take the civil service exam, all right.

Question 1: Design C35 concrete rebound measured C25?

First, it is possible that the strength of the concrete rebound in winter construction does not reach 75% of the design value.

Second, the surface mortar thickness of the pumped concrete slab is high due to the large water-cement ratio, and the surface layer should be hung off when rebounding, or rebounded after grinding with an angle grinder.

Thirdly, the construction and pouring concrete are not done well, and too much sand in the process affects the concrete labeling.

The harm caused by this can't be said, it depends on the part. If the residential buildings are better, it is not a big deal, but the industrial buildings are specially designed to have a greater impact on the buildings with vibration requirements. The conservative coefficient is generally different for different design institutes, which is about +30%.

Question 2: The protective layer of the reinforcement is 15mm, and the actual construction inspection is 25mm?

This also depends on the part, if the ordinary plate is almost not a big problem, but if the cantilever plate and also bear external force, the problem is serious, and it may break after reaching the full load. It is no problem that the cantilever plate of the ordinary canopy is not affected by external forces.

Problem 3: Rebar pulling.

The special masonry Rachel reinforcement of the building reinforcement belongs to the seismic and structural reinforcement, which can be said to be fine as long as it is not within ten years. However, if the industrial building fills the wall, the tie reinforcement is very important, especially if there is large equipment near the building and the seismic force is larger, and the elevation of the building itself is high, and the filling wall has no tie reinforcement for a long time to have a problem, the result is likely to fall down the wall, and it is not good to say whether it smashes people or not!!

Not according to the standard, generally speaking, in the actual construction and use, except for the first unacceptable, the other two problems have little impact on the normal use of the building.

In the first article, although each component of the building in the design will have a safety factor, as far as the building as a whole is concerned, the safety factor will be very large after accumulation, and at the same time, for the sake of safety, the designer will more or less increase the safety factor again, but it will not reach the extent of two marks of concrete. The safety of the building depends on how the user uses it (according to the original design load, it will definitely not work).

The protective layer is too large and will lead to a decrease in the bearing capacity of the component (but as mentioned above, the reduction of 10mm is very small), and the protective layer is too small to cause the steel bar to rust in advance, (but in the design process, only the carbonization value of the thickness of the concrete protective layer other than the steel bar is considered, and the impact of plastering, decoration, etc. on delaying the carbonization of concrete is not taken into account.) Therefore, it has little impact on buildings that are used in a normal environment).

It's a national problem for inaccurate layers of protection (even for the Luban Prize project). Among them, there are responsibilities of the construction unit and the responsibility of the design unit. Large construction units usually use shaped cushion blocks to be foolproof, but in the process of pouring concrete, there will still be displacement, damage and even no effect at all (the specific operators are mostly migrant workers, and the quality is generally not good).

Not to mention the small construction team, the protective layer is basically impossible. For high-rise and large frame structures, the problem of non-standard protective layer caused by the unscientific design drawings is more prominent, mainly because the position of the beam-column node is too dense, the number of layers is too many (three rows of steel bars and above are very common), and the protective layer of steel reinforcement can not be accurately controlled. The acceptance specification is allowed to be +-10mm, and in practice, even a few millimeters will not affect safety.

Unless the building is in a special use environment that may cause the rebar to be corroded in advance).

The description of the third problem is like the pull-out test of the tie bar used in the back masonry wall of the frame structure or shear wall structure, if it is not enough pull-out strength will not affect the safety of the building itself (the rear masonry wall itself is not forced), but it will have an impact on the plastering of the wall and other later decoration (such as cracks in the position), especially when the consequences are very serious.

1. The rebound strength is insufficient, and the design strength grade has a certain impact on the structure, but it is difficult to determine how much the impact is (mainly depending on the safety factor in the design calculation). Normally, the local regulations are like this, when the concrete does not meet the design requirements, according to the strength grade of the designed concrete: 20 concrete reaches 82% of the design strength, C25-C30 concrete reaches 85% of the design strength.

When C35-C45 concrete reaches 88% of the design strength and C50-C60 concrete reaches 90% of the design strength, it needs to be checked by the structural design and issued an approval document before it can be released. If the above strength cannot be reached, it is necessary to test the entity by a statutory testing agency and issue a test document, and if the structural entity can meet the design strength requirements, it will be released. If the test results cannot meet the design strength requirements, the structure needs to be identified structurally, and the reinforcement can meet the normal use function through reinforcement and reinforcement.

Otherwise, it will be disposed of according to the appraisal conclusion.

2. The thickness of the protective layer of the reinforcement does not meet the requirements, which will have an impact on the structure

a. If the protective layer is too small: it is easy to make the steel bar corrode, affect the service life of the steel bar, and have an impact on the quality of perception

B, if the protective layer of the reinforcement is too large: (the protective layer refers to the vertical distance between the outer edge of the stressed steel bar and the concrete surface), so that the moment of the stressed steel bar is too small, reducing the bearing capacity of the structure (equivalent to the structure in the tension area to reduce the cross-section), so the thickness of the protective layer in the reinforced concrete structure has a considerable impact on the quality of the structure. The new concrete quality acceptance specification squadron has made special provisions for this indicator that are different from any other indicators:

The measured thickness of the protective layer must ensure that more than 90% of the design requirements can be accepted (80% for all other projects).

3. The influence of the structure of the drawing test team of the planting reinforcement: the main function of the planting reinforcement is to make the concrete structure and the masonry structure form a whole when stressed, so the planting reinforcement needs to pass the drawing test before it can be released. If the pull-out test does not meet the requirements, it will directly affect the tie-up effect between concrete and masonry, and affect the overall stability of the structure.

People who have done quality inspection have experienced that sometimes it is difficult to find a balance, and it is difficult to reconcile the contradictions between conscience and responsibility, so you need to weigh the pros and cons of doing things, and mastering more knowledge may help you justify yourself

According to the "Regulations on the Quality Management of Construction Projects":

Article 43 The State implements a system of supervision and management of the quality of construction projects.

The construction administrative department shall implement unified supervision and management of the quality of construction projects throughout the country. Railway, transportation, water conservancy and other relevant departments in accordance with the provisions of the division of responsibilities, responsible for the supervision and management of the quality of the relevant professional construction projects across the country.

The local people's construction administrative departments at or above the county level shall supervise and manage the quality of construction projects within their respective administrative areas. The local people's departments at or above the county level such as transportation and water conservancy shall be responsible for the supervision and management of the quality of professional construction projects within their respective administrative areas within the scope of their respective responsibilities.

Article 53 All units and individuals have the right to report, accuse and complain about quality accidents and defects in construction projects.

First, you need to find the right reporting unit. It should be reported to the administrative department or the industry authority.

Second, you need to have real evidence. Try to get the video materials of the relevant questions, firstly, to make people credible, and secondly, to make him feel stressed if he does not accept them. Record the unit, position, name, time, place, etc. of the person receiving you, so as to facilitate the second complaint to the people's congress, the supervision department or **.

Third, if there is a problem in the project of your unit, it is recommended to communicate with the superior leader to help solve the problem of project management. It doesn't have to be reported.

Report to the competent department of the project where the project is located first. If the competent authority also does not act, it can be done online**.