The Code stipulates that special construction plans shall be made for the erection of formwork supports, and the structural design shall be designed and calculated, and the examination and approval shall be carried out according to the regulations.
As shown in the above figure, the reinforcement of a column is offset by 150mm.
If the protective layer is too small or the reinforcement is leaked, the life of the building will be shortened.
The lack of stirrups will greatly reduce the shear capacity of this part and greatly reduce the bearing capacity.
There are changes during concrete pouring, and the final result is not good.
5.
The steel bar trade union thought of such a time-saving and labor-saving method.
Hot bending is to heat the steel bar with oxygen flame and then bend it.
It just touches the edge.
If necessary, the design unit shall be invited to adjust the design, and it must not be cut at once.
In the process of straightening, some straightening machines will straighten the reinforcement while straightening the reinforcement, which also belongs to thin reinforcement.
In addition, the distance between the welding point and the bending point of the reinforcement shall be greater than 10 times the diameter of the reinforcement, which is the same as the principle of hot bending of reinforcement mentioned in Article 5.
Once the facts are formed, the consequences can be imagined.
The formwork support shall be lifted directly from the backfill without tamping.
The specification requires that one-sided welding should meet 10 times of reinforcement diameter and two-sided welding should meet 5 times of reinforcement diameter.
This is also the reason why steel bars are bent repeatedly.
The tensile strength of these reinforcement is less than the requirements of specifications and standards.
For example, the steel bar that needs to be bent is tied straight.
The reinforcement between components (such as beam and column) establishes the connection between components by anchoring.
The first floor is strictly required, so it is dense, and the point is reduced to the second floor.
Is it OK? 8.
The deviation of wall (column) reinforcement refers to the deviation of reinforcement position.
Slimming reinforcement is the reinforcement whose diameter deviation does not meet the requirements.
There are not a few construction sites with reduced horizontal poles.
Some people think it’s troublesome to reduce one or two.
During concrete pouring, the reinforcement needs to be watched by a specially assigned person to prevent the reinforcement from being trampled and deformed during concrete pouring.
The stress of the steel bar connection with straight thread connection completely depends on the mechanical bite force of the thread.
4.
Lack of stirrups the requirements for stirrups are as follows: when the column meets the beam, there must be stirrups in the column, and when the main beam meets the secondary beam, the main beam must have stirrups.
The end face of the straight thread joint reinforcement is uneven.
The strength of reinforcement will be greatly reduced.
As shown in the figure above, the reinforcement in the floor is divided into upper reinforcement and lower reinforcement, All crowded together and inseparable, how to bear the force correctly? Two.
After the reinforcement is offset, different treatment schemes must be adopted according to the size and severity of the offset.
After entering the site, the coiled reinforcement needs to be straightened.
The earthwork backfilled is equal to the foundation of the formwork support.
Once used in engineering, it will reduce the bearing capacity of concrete components.
For example, the beam reinforcement needs to meet a certain length into the column.
According to the requirements of the specification, the horizontal bar is required to be connected vertically and horizontally.
9.
The most serious consequence: collapse.
Before concrete pouring, various measures should be taken to ensure it, and it should be carefully reviewed.
During concrete pouring, there is no one to watch.
The reason does not need to be explained in detail.
3.
Generally, the steel bar is corrected after being tied incorrectly.
The straight thread connection of the reinforcement has the advantages of simple processing and convenient connection.
10.
7.
According to the design requirements, there are 8 column reinforcements in total, and 5 reinforcements will be located outside the column! The severity can be imagined! There are many reasons for the deviation.
After the third floor, the management personnel are on the road, the inspection is relaxed, and then it is reduced layer by layer.
The most serious consequence: collapse.
The exposed thread outside the straight thread is too long, which is also a straight thread.
It can be broken without pliers.
Therefore, According to the requirements of the standard atlas, we must find out the anchorage length of all kinds of reinforcement and meet the requirements.
The reinforcement anchorage is not enough.
The deviation of reinforcement can be caused by construction errors, drawing errors and deformation during concrete pouring.
This reinforcement connection is like kissing.
The weld length of reinforcement welding is not enough.
Some reinforcement are well bound and the position and size meet the requirements.
The earthwork backfilling of some projects is in the rush period..
However, it is common sense that steel will be tempered when heated and then cooled.
In this way, the overall stiffness of the formwork support is reduced.
The thread leakage is too long, which means that the screw in length is not enough.
If the end face is uneven, it means that the effective screw head screwed into the sleeve is reduced, which reduces the bearing capacity of the steel bar connection part.
6.
We hold a thin iron wire in our hand and bend it repeatedly for several times.
Steel bar bending is baked by electric welding.
Therefore, the reinforcement needs to enter the concrete with a certain thickness, which is the protective layer.
One direction is completely open, and the other direction? There are those who pull one after another, those who pull one after two, and even those who pull one after three or four.
Rust will reduce the diameter of the reinforcement and endanger the life of the building.
Steel bar bending must adopt the method of cold bending and cannot be bent repeatedly.
Template engineering 1, the spacing between vertical poles is reduced or reduced.
2.
The erection distance of 800mm is required to be 900mm, and the erection distance of 900mm is required to be 1000mm.
Is it really invisible if the concealed works are concealed? 1.
When the welding length is not enough, the strength of reinforcement connection area will be reduced.
If the reinforcement binding is carried out in a barbaric way, the construction site personnel ignore it and directly pour concrete, it will bring irreparable serious consequences.
When the thin steel bar and formed steel bar enter the site, the test pieces shall be taken for the inspection of yield strength, tensile strength, elongation and weight deviation, and the inspection results must comply with the provisions of relevant standards.
Later, there was no problem.
In some projects, the erection distance of poles is more than 1200mm.
According to the specification requirements, the beam reinforcement must cross the column centerline by 5 times the reinforcement diameter.
There is no need to use electricity on the connection site, so it is widely used in construction sites.
The anchorage is too short, and the reinforcement may be pulled out during the stress process of components.
The thickness of the concrete protective layer is insufficient, and the reinforcement will rust if exposed to the air for a long time.
However, it is common that the construction is not carried out according to the scheme during site erection.
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