company news about What are the concrete quality points of steel structure engineering

1Measures for construction supervision of steel structure

1.1 For steel structure members in the manufacturing, transportation, hoisting, support location, welding, testing, rust removal, coating and other links, supervision should be key control, to ensure that the project planning, detailed rules, operation procedures, construction link method, link.

1.2 Selecting and assigning supervisors with a strong sense of responsibility and experience in steel structure construction shall be responsible for the supervision of steel structure projects. When necessary, selecting and assigning supervisors from companies and departments shall deal with all kinds of difficult problems arising in the project in time according to the project requirements.

1.3 In order to ensure the quality and safety of the whole project, carefully implement each procedure of each link according to the agreed steel structure construction plan, standards, strict requirements, frequent inspection, quality pre-control and process sidelining;Artifacts from the material, drawings sample, serial number, processing, manufacturing, factory supervision, transportation mobilization, the accumulation is assembled as planned, all or part of the lifting, support _ and node welding is in accordance with the requirements of planning rules, quality standards, standards for the whole process, the comprehensive supervision, automatic coordinated planning, construction, installation at the moment of rules, according to the required quality standards.

1.4 Check the mechanical function and weldability of raw materials, and strictly control the quality;Check the welding function of the welding specimen;Key points to carefully control the welding personnel and conditions to ensure welding quality and safety;All or part of the hoisting should first check whether the scheme meets the project quality and safety requirements, to ensure the reasonable sequence and progress of the process;Strictly check and control the positioning, wind speed influence and deflection value, and adopt the method of shadowing and measurement for on-site supervision;In the process of welding constantly detect each process and welding process, adopt the side inspection, observation, beating and non-destructive inspection techniques for supervision;The key is to control the construction quality of the welding process such as high-altitude welding and overhead welding, and the condition is to ensure the quality and stability of all.

1.5 Key controls should be carried out in the following links:

1.5.1 Components are prone to deformation during transportation or accumulation, so it is necessary to use weld gauges, measuring things, pull wires and other methods to check during manufacturing and welding of components and during transportation. If deformation is found, targeted corrective measures shall be adopted to deal with it in time.

1.5.2 During component assembly and welding, defects such as distortion, deformation, arching error, displacement scale error, device deflection error and instability shall be prevented;, weld layout condition, welding sequence and heat bilges cold shrink caused by temperature and the temperature of Yin and Yang, drooping component weight error, the cumulative error of welding, synchronous lifting velocity error, etc of the multi-level control, use view and measurement technique for simple process of all kinds of error occurred in a timely manner the Shadowed, calibration and monitoring, adopt measures of prevention and useful way to control error, such as selection reasonable welding sequence, the right operation method, abundant considering the influence of the environmental elements, splicing gap, material thickness difference, difference degree of preheating, and the necessary test results to determine the cohesion of a better method.

1.5.3 When lifting components, first of all, the lifting quality shall be ensured, which is safe and reliable and convenient for assembly and operation, and insurance protection, support and reinforcement shall be considered for the surrounding completed structures;Adequate attention should be paid to adverse elements such as bad weather;It is also necessary to check the uniform testing steel ruler, adjust the temperature correction and control the scale error of the small assembly unit, the middle assembly unit and the deformation error of the total assembly system, so as to ensure the structural installation accuracy of the steel structure engineering.Field aerial work _, affected by various factors influencing quality of _ prone to error, and so on these special link separation and formulate detailed measures for the construction scheme and technical support of supervision is the formulation of the detailed rules for the implementation of the relevant, special engineering technical disclosure is necessary to implement to the people, to make every construction movement, every process is under controlled conditions to form a multi-level and _ quality control system.

2 Key monitoring points:

2.1 Material testing:

2.1.1 Steel selected for steel structure engineering shall have quality certificate, and shall meet the Q345B requirements of the planning requirements. The raw materials shall be sampled and inspected according to the current rules of relevant standards, and the processing can only be done after passing the test.When the steel surface has defects such as rust, pitting or scratches, the depth shall not be greater than 1/2 of the negative error value of the steel thickness.

2.1.2 The connecting materials and coating materials selected for steel structure engineering shall have the quality certificate of the factory, and shall meet the planning requirements.The high strength bolt coupling pair should check the load of bolt wedge, nut guarantee load, nut and washer hardness, the mean value and coefficient of variation of fastening axial force of coupling pair in time.The application shall be permitted only after passing inspection.

2.2 Steel structure manufacturing

2.2.1 Steel structure manufacturing shall be entrusted to a qualified steel structure processing plant, which shall be selected according to the processing capacity, production equipment, production technology, detection methods, quality assurance system, and similar engineering experience of the processing plant after investigation.

2.2.2 Review of steel structure manufacturing scheme: the steel structure manufacturing scheme can only be implemented after it is necessary to review and agree.Sent supervision in the factory, to check each procedure after acceptance before entering the next procedure.

2.2.3 Control points of steel structure manufacturing:

2.2.3.1 Lofting and marking: first of all, a 1:1 sample should be released, and the marking and cutting can only be done after the inspection and approval of the supervision engineer.According to the process requirements, the lofting and marking materials shall be reserved for the welding shortening allowance and cutting, edge planing and other processing allowance during the manufacturing and installation.Lofting error: parallel line distance and segmenting scale ±0.5mm, diagonal 1.0mm, width, length, hole distance ±0.5mm.The allowable error of the marking material: the dimension of the parts is ±1.0mm, and the hole distance is ±0.5mm.

2.2.3.2 It is necessary to choose automatic cutting. Before cutting, rust and dirt on the surface of steel cutting area should be removed and cleaned, and slag and splashes should be removed after gas cutting.Allowable error of gas cutting: width and length of parts ±3.0mm, flatness of cutting surface ≤ 0.05T (T is the thickness of cutting surface) and not greater than 2.0mm, cutting depth ≤0.2mm, partial notch depth ≤1.0mm.Mechanical shear parts, the thickness of the steel plate should not be greater than 12.0mm, shear surface should be flat, its allowable error: parts width and length ±3.0mm, marginal edge ≤1.0mm.

2.2.3.3 Drilling: All bolt holes shall not be cut into holes by gas, but shall be drilled by numerical control drilling machine. It is necessary to use sleeve drilling for bolt holes of interconnected plates to ensure the accuracy of bolt penetration.When the allowable error of the bolt hole exceeds the rule, the steel block shall not be used for filling, and the welding rod matched with the base material can be used for redrilling after welding.