Coefficient inspection of steel structural bolts
Coefficient inspection of steel structural bolts
The Code for Acceptance of Steel Structures GB50205 clearly stipulates that the production and installation units shall conduct anti slip tests and re inspections respectively (Article 6.3.1 of the strong clause). The anti slip coefficient must be greater than or equal to the design value.
Inspection of anti slip coefficient of high-strength bolt connection pairs in steel structures
(Yongnian Fastener - Steel Structure High Strength Bolt Connection Pair)
In the inspection of engineering data, many construction sites only have anti slip coefficient test reports from the manufacturing plant in the factory, and there is a lack of retest reports on the anti slip coefficient of specimens provided to the construction site.
The inspection of anti slip coefficient should be based on the manufacturing batch of steel structure bolts, with each 2000t of a single project as a manufacturing batch, and those less than 2000t should be considered as a batch. When two or more surface treatment processes are used for the friction surface of components in a single project, each surface treatment process needs to be inspected. Three sets of specimens per batch.
The conventional treatment methods for friction surfaces mentioned in GB50017-2003 include sandblasting (shot blasting), applying inorganic zinc rich paint after sandblasting (shot blasting), and generating red rust after sandblasting (shot blasting).
It should be pointed out that many engineering projects have high anti slip coefficients for inspection, and the actual friction surface treatment of components is poor, completely unable to meet the design requirements for anti slip coefficients; Alternatively, the friction surface required by the design is coated with inorganic zinc rich paint after sandblasting (shot), while the one submitted for inspection is unpainted (with reduced friction coefficient after painting). For projects with large values of anti slip coefficient design, if such situations are found by on-site supervision, they must be ordered to rectify and retest the friction surface after treatment, otherwise serious quality hazards may be left behind.
The company's main products include high-strength bolts, high-strength nuts, steel structural bolts, steel structural nuts, grid sealing plates, grid bolts, etc.
