In actual construction, there are often some construction machines and tools that need to be temporarily connected to the power supply for short-term work, and the electrician on site often ignores the power safety of such temporary loads, and does not operate the wiring according to the specifications in order to facilitate and save trouble.
In the actual inspection, it was found that the power cord was directly hung on the fuse after removing the bakelite cover of the knife switch. On the one hand, the fuse of the knife switch was exposed, which was easy to cause electric shock accidents. On the other hand, the lap joint of the power supply is easy to be oxidized, and the wire will heat up.
The potential safety hazards such as aging lines, wrapping of broken skins, and many line joints in the construction of steel formwork should be rectified in time to eliminate the hidden dangers of construction electricity. Each electrical equipment must meet the requirements of "one machine, one gate, one leak and one box", the line markings must be clear, the wire ends must be clean and tidy, each electrical box must have a door with a lock, and some switch boxes of individual distribution boxes must be damaged. It should be replaced in time.
In the event of thunderstorms, turn off the electrical equipment of the steel props formwork and cut off the power supply in time to avoid equipment damage or safety accidents. Do not stack sundries next to the electrical equipment, which will affect the heat dissipation of the equipment and easily cause potential safety hazards. Temporary power lines and equipment that do not comply with safety regulations or have potential safety hazards shall not be put into use. All electrical equipment must be well grounded and installed in a relatively fixed position, and must not be disassembled at will, and wires and electrical equipment must not be added at will. Electrical equipment and wiring must meet specifications and should be serviced regularly.
After the steel bars and steel formwork for concrete are checked and qualified, the concrete pouring starts. After the concrete is mixed, it is placed in the ash hopper one on the truck, and a string cylinder is set to prevent segregation. It is transported to the prefabrication yard by truck, and then the ash hopper is lifted by the gantry crane in the yard for pouring. The concrete shall not segregate. The pouring sequence is to pour the bottom plate first, then pour the rib plate and the top plate, and pour it to the other end in longitudinal sections and horizontal layers.
Concrete vibrating is a method of combining mechanical vibrating as the main and artificial vibrating as a supplement. When using a plug-in vibrator, the moving distance should not exceed 1.5 times the action radius of the vibrator; the distance from the side formwork should be kept at least 50 mm; the lower concrete should be inserted 50-100 mm; after each vibration is completed, the vibrating rod should be slowly raised while vibrating; try to avoid vibrating rods colliding with steel formwork, steel bundles and other embedded parts.
In the process of concrete pouring, a special person is arranged to be responsible for the inspection of the concrete vibrating quality, to prevent leakage of injection and vibration, to solve the problem in time, and to formulate the method of rewarding the good and punishing the poor, so as to strengthen the responsibility of the construction personnel.
After the concrete is finally set, the inner formwork shall be removed. When the formwork is removed after the steel formwork rental is used up, the surface and edges of the beam body must not be damaged, otherwise the formwork removal time after the steel formwork rental has been used up will be delayed.
Generally, the demolding time is controlled at about 12 hours after the steel formwork rental is used up. Remove the inner mold first and then remove the outer mold. Through the observation of the appearance quality of the prefabricated beams after the steel formwork has been rented and demolded, there is a small amount of air bubbles in the chamfered part of the bottom plate, and there are almost no air bubbles in the rib plate, and the overall appearance quality is good.