2.3 when more than one reinforcement is reserved with a reinforcement hole (slot) or the hole (slot) is large, the binding spacing of the reinforcement framework is not controlled accurately, resulting in the deviation of the reserved reinforcement.

2.5 during the transportation, hoisting and installation of semi-finished reinforcement and finished reinforcement framework, effective anti deformation support measures are not taken, resulting in the torsion or displacement of the reserved reinforcement framework.

2.8 during the concrete pouring process, the vibrating rod excessively impacts the reserved surface reinforcement, resulting in the displacement of the reinforcement position.

Fixing Socket Angular End Nail Plate

3.2 management measures 3.2.1 before reinforcement processing and fabrication, the material extractor of the operation team shall carefully consult the design drawings, formulate the blanking table in strict accordance with the design requirements, and the team shall cross check the blanking table to prevent the preparation error of the blanking table.

3.2.4 strictly implement the “three inspection system” and concealed acceptance system.

3.1.2 each reinforcement shall be provided with a reinforcement hole separately, and multiple reinforcements shall not share a reinforcement hole.

03 prevention and control measures 3.1 construction measures 3.1.1 no reinforcement slots are left, all are reserved as reinforcement holes, and the reinforcement at the top is bent, and then bent after the formwork is removed.

04 key points of quality control 4.1 reinforcement blanking sheet.

2.7 the “three inspection system” and concealed acceptance system were not strictly implemented.

3.2.3 the protection of finished products should be strengthened during transportation, storage and installation.

2.6 before concrete pouring, the existing reinforcement framework was not corrected.

There should be no gap between the rubber plug and the mold after installation, and there should be no gap between the reinforcement and the rubber plug after threading.

2.2 the preformed component mold has reserved reinforcement holes (slots) and the sleeve installation and positioning is inaccurate.

3.2.2 the first article acceptance system shall be implemented for members of the same specification and model, and the quality inspector shall conduct joint acceptance with the team to find out the problems, analyze the causes, and formulate corrective measures.

The aperture and the specification of the hollow rubber plug should be reasonably determined according to the diameter of the reinforcement.

02 cause analysis 2.1 the operators did not carefully consult the design drawings, and the quality inspectors did not strictly implement the “three inspection system”, resulting in the specification, quantity and cutting size of reinforcement not meeting the design requirements.

3.1.3 when the numerical control machine tool laser cutting machine is used to drill holes on the mold, when the numerical control machine tool laser cutting machine is not used to drill holes, the position of the reinforcement hole should be accurately measured in advance, and the line should be drawn.

Content source: Guide to prevention and control measures for common problems of engineering entity quality in Hebei Province (2021 Edition) 01 phenomenon description the specification, quantity, location and size of reserved reinforcement in precast components do not meet the design requirements, especially the grouting connection of wall reinforcement sleeve, which leads to installation difficulties due to inaccurate positioning of reserved reinforcement and grouting sleeve (as shown in Figure 1.1).

2.4 the steel bar framework is not cross bound with binding wires, and the binding points of the steel bars are loose and displaced.

4.3 reinforcement framework binding…

4.2 location, diameter and rubber plug specification of reinforcement hole.

The round hole should be drilled with a magnetic drill, and the special-shaped hole should be drilled with a plasma cutting machine.