Pc prefabricated stair quality problems in the production process:
There are two ways to produce prefabricated stairs: First, “vertical” production, the staircase mold is divided into three parts: step mold, one side mold, two end molds; second, “horizontal” production, that is, stepping Under the production, the staircase mold is divided into three parts: the step mold, the two side molds, and the two end molds. Among the production methods of the two production methods, the problems that are prone to occur are:
1) Template engineering. The surface of the mold is not clean, and rust marks and watermark marks appear on the mold;
2) Steel works. There are errors in the straightness of the steel bar, the length of the steel bar, the size of the hook, the position error of the steel bar, the quality of the steel bars and the welded joints;
3) Concrete works. Quality problems such as concrete strength, slump, pouring time, concrete vibration, surface compaction, trowel, etc.;
4) Maintenance engineering and demoulding. Quality problems occur in concrete curing time, temperature control, and mold removal protection.
Stair production process quality control measures
In view of the problems arising in the above-mentioned prefabricated staircase production process, we should take measures from various channels to solve or avoid the above problems, in order to improve the production quality of prefabricated stairs.
2. 1 mold cleaning and quality requirements
The floating soil, sealing strip, tape paper, concrete residue, etc. on the mold are cleaned, and rust marks and watermark marks appear on the mold, and the employees are required to use sandpaper to polish the mold to ensure the cleanliness of the mold. After the cleaning is completed, the sealing strip is attached to the contact part of the side mold and the mold; the concrete floating slurry, floating ash, oil stain, rust, etc. are cleaned on the mold, and then a layer of release agent is uniformly coated on the board surface with a rag. .
2. 2 Rebar engineering and quality control measures
1) The steel bars should not be bent and the surface should be smooth, free from oil and rust.
2) Rebar processing ingredients. The technician should be familiar with the drawings before processing the ingredients, and require reasonable ingredients according to the shape and length of the steel bars reflected on the drawing of the components.
3) The steel bars are straightened by the cold drawing method.
4) Familiar with the drawings before the steel bars are tied, understand whether the dimensions and labels of the components are the same as the mold types, and assemble the mold according to the inner wall production dimensions in the drawings. Verify that the manufacturer, size, number of steel bars on the drawing match the existing processed steel bars. Understand the spacing of the bars in the drawing for easy lashing operations.
5) The welded and bundled steel mesh and steel frame should be firm. For welding mesh and welding frame, the number of leakage welding and welding shall not exceed 4% of the total number of welding points, and there shall be no leakage or welding of adjacent two welding points; except for the drawings, the steel bars shall not be allowed to be welded. Cut off. If the steel bar is cut, the compensation rib should be added along the direction of the force of the cut steel bar.