ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
1.1 steel structure rod length ratio detection and accounting, the rod size can be measured according to the provisions of Section 6.4 of this chapter, the length ratio of the rod should be calculated according to the actual size.
1.2 The connection of the steel structure support system can be tested in accordance with the provisions of Section 6.3 of this Chapter; the dimensions of the support system components can be determined in accordance with the provisions of Section 6.4 of this Chapter; they should be verified or assessed according to the design drawings or the corresponding design specifications.
1.3 The width-to-thickness ratio of the cross-section of steel structural members can be measured and calculated according to the provisions of Section 6.4 of this Chapter, and should be assessed according to the design drawings and relevant specifications.
2.1 The quality of steel structure protective coatings should be tested according to the relevant national product standards for coating quality. The descaling grade of the steel surface of
2.2 can be determined by the picture comparison observation of the current national standard "Corrosion grade and derusting grade of steel surface before painting" GB8923.
2.3 coating thickness of different types of coatings should be tested by the following methods:
1 film thickness, can be detected by paint film thickness gauge, the number of sampling components should not be less than the minimum capacity of Class A test samples in this standard table 3.3.13, It should also be no less than 3 pieces; each piece is measured at 5 places, and the value of each place is the average of 3 dry film thicknesses of the measuring points 50 mm apart.
2 for the thickness of thin fire-retardant coatings, can be tested by coating thickness tester, the amount of test method should meet the requirements of CECS24 "Technical Specifications for Application of Fire-retardant Coatings for Steel Structures".
3 for thick fire-retardant coating thickness, should be measured by stylus and steel rule, the measurement method should be in accordance with the "Technical Regulations for the Application of Fire-retardant Coatings for Steel Structures" CECS24. The thickness value and deviation value of the coating shall be assessed in accordance with the provisions of GB50205 for the Acceptance of Construction Quality of Steel Structure Engineering. 6.7.4 The appearance quality of the coating can be tested and evaluated according to the different materials according to the "Code for the Acceptance of Construction Quality of Steel Structure Engineering" GB50205.
3, steel grid
3.1 steel grid can be divided into the bearing capacity, welds, dimensions and deviations, the flatness of the rod and the deflection of the steel grid.
3.2 The test of the bearing capacity of the welded ball joints and bolt ball joints of the steel grid shall be carried out in accordance with the requirements of JGJ78 of the "Quality Inspection and Evaluation Standard for Grid Structure Engineering". For the existing bolt ball node grid, the node can be taken out from the structure to test the ultimate bearing capacity of the node. When intercepting the bolt ball node, measures should be taken to ensure the structure is safe.
3.3 welds in steel grids can be tested by ultrasonic flaw detection. The inspection operation and evaluation should be based on the ultrasonic flaw detection and mass classification method of welded ball joint steel grid welds. JG/T3034.1 or "bolt ball joint steel grid weld seam ultrasonic wave" The requirements of the flaw detection and quality classification method JG/T3034.2 are carried out. The appearance quality of the welds in the 3.4 steel grid shall be tested in accordance with the requirements of GB50205 for the Acceptance of Construction Quality of Steel Structure Engineering.
3.5 Welding ball, bolt ball, high-strength bolt and rod deviation detection, detection method and deviation allowable value shall be carried out in accordance with the provisions of JGJ78 of "Grid Structure Engineering Quality Inspection and Evaluation Standard".
3.6 steel grid steel pipe wall thickness can be detected by ultrasonic thickness gauge, the finish layer should be removed before testing.
3.7 The unevenness of the axis of the rod in the steel grid can be detected by the method of pulling the wire, and the unevenness should not exceed one thousandth of the length of the rod.
3.8 The deflection of the steel grid can be detected by laser range finder or level gauge. The number of points in each half span should not be less than 3, and there should be 1 measuring point in the span. The end measuring point should not be larger than the end bearing. 1m.
4, structural performance real load test and dynamic test
4.1 for large complex steel structure system can be in situ non-destructive real load test, direct inspection of structural performance. The actual load test of structural properties may be carried out in accordance with the provisions of Appendix H of this standard. The loading factor and the determination principle can be determined according to the provisions of Appendix H.2 , and can be adjusted according to the specific circumstances.
4.2 When there is doubt about the bearing capacity of a structure or component, a prototype or full-scale model load test can be performed. The test should be commissioned by a specialized agency with sufficient equipment capabilities. A detailed test plan shall be prepared before the test, including the purpose of the test, the selection or fabrication of the test piece, the loading device, the arrangement of the measuring points and the test instrument, the loading procedure, and the evaluation method of the test results. The test plan may be formulated in accordance with Appendix H and shall be approved by the parties concerned prior to the test.
4.3 For large-scale important and new steel structure systems, it is advisable to carry out actual structural dynamic tests to determine the dynamic parameters such as the natural vibration period of the structure. Structural dynamic testing should be in accordance with the provisions of Appendix E of this standard.
4.4 The stress of the steel structural members can be selected according to the actual conditions using a resistance strain gauge or other effective methods.