by According to the inspection of project quality for many years, it is found that there is a kind of quality problem.
Although it has been repeatedly emphasized, serious errors still occur repeatedly.
This is true for almost all projects, without exception.
Therefore, a quality problem that needs high attention is put forward, that is, how to improve the quality of cantilevered components such as balconies, awnings and bay windows.
The equipment such as balcony, awning, convex window plate, post-cast strip, construction joint, tower crane and so on pass through the surrounding plate of the floor opening and other cantilever beam and slab components, and the stress reinforcement is located at the upper part of the beam and slab, which is just opposite to the stress position of the beam and slab reinforcement of other frame structures.
If the position of the stressed main reinforcement is reversed, it will lead to the collapse of the overhanging components such as the balcony, awning, projecting window panel, causing serious quality hazards and safety accidents, and even endangering the personal safety.
Therefore, it is necessary to maintain a high sensitivity to the engineering quality of cantilever components from the aspects of design drawings, construction and use.
1.
Design drawings: as a special topic, the structural descriptions and nodes of cantilever members in the drawing design shall be intensively arranged.
2.
Construction: poor cognition, insensitive! Repeated emphasis, repeated hit! The skilled man is bold, but the ignorant man is more bold! Almost all projects, without exception! For the items shown in the above figure, the upper load-bearing reinforcement of the secondary structure convex window cantilever slab above all floor slabs has not been padded with stool reinforcement according to the specification requirements, resulting in the upper reinforcement being offset to the bottom or the middle of the slab, making the concrete protective layer of the upper load-bearing reinforcement reach 55mm, seriously failing to meet the design requirements of the drawing that the thickness of the protective layer of the cantilever slab reinforcement should be 15mm, and losing the stress effect, A large number of convex window cantilever plates have major structural quality risks of cracking and collapse, and there are many places where the main reinforcement is not vertical, the distribution reinforcement is not through, and other situations that are not constructed according to the design drawings.
It is required to make thorough rectification and serious treatment to prevent similar problems in subsequent projects, and to conduct a comprehensive inspection of whether the concrete of the constructed convex window cantilever plate is cracked.
How to improve the quality of cantilever components? Model leads the way! How to improve the quality of cantilever components? Model leads the way! Training disclosure, repeated emphasis! 3.
How to improve the quality of cantilever components in accident cases? Improve cognition and combine knowledge with action.
The characteristics of the construction of secondary structural cantilevered components such as bay windows and awnings are as follows: large working face, scattered projects, difficult to supervise, insufficient attention paid by management personnel in ideology, insufficient awareness of the seriousness of the problem, and easy to cause serious quality problems such as cracking and local collapse.
There must be a plan for what happens in advance! The specific prompt requirements are as follows: 1.
For the concealed acceptance of the reinforcement of each cast-in-place component, the cantilever component, especially the cantilever component in the secondary structure, must arrange special acceptance personnel to take photos and send them to the project management WeChat group at that time; 2.
For the concrete pouring of cantilever components, especially the cantilever components in the secondary structure, each cast-in-place component must be sent to the project management group by arranging supervisors to take photos and videos at that time to confirm that the vibration is qualified; 3.
For the concrete curing of cantilever components, especially the cantilever components in secondary structures, each cast-in-place component must be arranged with a supervisor to take photos and send videos to the project management group at that time.
The cantilever concrete component is a sensitive part, which should not be careless.
We must pay high attention to the construction quality of each link, especially the position of the upper load-bearing reinforcement, which must be constructed in strict accordance with the drawing.
There must be no fluke mentality of cutting corners.
The upper load-bearing reinforcement is offset or even reversed, which is the most fatal error.
This is the key of the cantilever concrete component.
The main reinforcement of the cantilever concrete member is located at the upper part of the member to ensure the position and quality of the main reinforcement.
This is the most important lesson in the life of an engineer.
It is the touchstone to measure whether an engineering manager is knowledgeable, and it is the watershed to test whether an engineering manager has real skills and whether it is a poor number.
The horse stool reinforcement is the key to ensure the correct and effective position of the tension reinforcement at the upper part of the cantilever plate.
It must be installed in place before acceptance and bound firmly with binding wire.
There must be no such borrowing as “not in time”, “last addition”, “reinforcement with formwork inspection during concrete pouring” and so on.
When you think of it, you should do it immediately, improve your cognition, combine knowledge with action, and be brave to be a terminator.
To ensure the engineering quality of cantilevered concrete components such as balconies, awnings and protruding window panels, and to keep the bottom line, is the technical literacy and professional ethics that every project manager must have.
This directly relates to the safety of people’s lives and property.
Ignoring the engineering quality of cantilevered components is a crime, and will pay a heavy price, be punished by the law, and even lose freedom and life..
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