(1) When steel bars enter the site, they shall be accompanied by the ex-factory quality certificate or ex-factory inspection report, and visual inspection shall be conducted. The steel bars that fail the visual inspection shall be eliminated in time. Check whether the marks on each bundle or plate of steel bars are the same as the model and batch number (furnace number) of the ex-factory quality certificate, and whether the specifications and models meet the design requirements. ?
(2) The main construction machines and equipment include butt welding machine and its supporting butt welding platform, straightening machine, rust remover or wire brush, steel bar cutter, steel bar bender, electric welding machine, insulating shoes, protective sunglasses, etc. The quantity is determined according to the size of the processing plant. ?
Technical requirements?
(1) The mechanical equipment used has qualified factory certificate and service life. (2) Before large-scale processing and installation of reinforcing cage, the construction process test shall be conducted to determine the process parameters. ?
(3) The diameter, spacing and verticality of the reinforcing cage should meet the design and specification requirements. ?
Construction preparation requirements:
When the reinforcement comes into the site, its variety, grade and specification meet the design requirements, and it is accompanied by product certificate, attachment list and related material report or inspection report. On-site quality inspectors have carried out visual inspection as required, and the mechanical properties of the acceptance batch are sampled at 60t. ?
The inspection of hot-rolled round steel and hot-rolled ribbed steel bars shall comply with the regulations; Weldability test and welding parameter test are carried out before formal welding to obtain corresponding welding parameters; Prepare ingredients according to the bill of materials or technical disclosure; Masonry isolation fence, build steel processing shed, harden site, repair and improve drainage system, and plan site.
Construction requirements? Steel warehouse?
After the appearance inspection of steel bars is qualified, they should be stacked according to the varieties, grades, brands, specifications and manufacturers of steel bars, and they should not be mixed, and identification signs should be set up. ?
Steel bars should be stored in warehouses or sheds to avoid corrosion and pollution. When stacked in the open air, it should be stored overhead, not less than 300 mm from the ground, and should be covered.
Rust removal of steel bars
How to deal with it?
Oil stain, floating skin and rust on steel bars should be removed, which can be stripped by knocking. A large number of rust removal can be completed by cold drawing of steel bars or straightening process of steel bar straightening machine; A small amount of steel bars can be derusted by electric derusting machine or sand blasting, and the local derusting of steel bars can be derusted by manual wire brush or grinding wheel. ?
Matters needing attention and quality requirements?
Whether there are serious pits and spots on the surface of the steel bar after rust removal. When the damaged section is damaged, it should be degraded or removed, and the steel bar with honeycomb rust should not be used.
Strengthen ingredient shaping?
Preparation of ingredient list: the steel bar should be straight without local bending, and the bent steel bar should be straightened before use. Straightening can be done by cold drawing or straightening machine. Cold-drawing method is mostly used to straighten thinner steel bars, and straightening machine is mostly used to straighten thicker steel bars.
When straightening with cold drawing method, it should be pulled slowly at a uniform speed. The cold-drawn rate of grade I rebar should be ≦ 2 ?, and that of brand rebar should be ≦/kloc-0 ?. When straightening steel bars with straightener, surface scars should not reduce the cross-sectional area by more than 5%. Straightened steel bars should be straight without local bending, and there should be no obvious scratches on the surface of cold-drawn low-carbon steel bars. ?
Steel bar blanking?
Before blanking, carefully check the specifications, grades and processing quantity of steel bars, and then blanking according to the ingredient list. Before the steel bar is bent and formed, it should be cut according to the length required by the ingredient list. Generally, a steel bar cutter is used. Without equipment, wire cutters and manual hydraulic cutting can be used. ?
Before cutting the steel bar, mark it with chalk according to the blanking length of the ingredient list, and clearly mark the cutting position. When cutting, aim the cutting mark at the blade, put the steel bar into the cutting groove and cut it off. ?
The reinforcement of the same specification shall be collocated and arranged as a whole according to different lengths; Generally, long materials are cut first. After cutting short material, the short head and loss are reduced. Avoid measuring long materials with a short ruler to prevent accumulated errors. The workbench should be marked with size and scale, and a baffle should be set to control the size of broken materials. In the process of cutting, if splitting, shrinking or severe bending is found, it must be removed. After cutting, the fracture surface of steel bar shall not be horseshoe-shaped or bent, and the length deviation of steel bar shall not be less than 10mm 4.4.4? Semi-finished steel bars shall be processed centrally in the processing shed. ?
Bending forming of steel bar
How to deal with it?
The bending forming of steel bars is usually carried out by a bending machine. Spiral rib molding, small diameter can be formed by tambourine; Thick steel bar. A processing disc made of section steel can be arranged on the working disc of the steel bar bending machine, the outer diameter of the processing disc is equivalent to the inner diameter of the spiral steel bar to be processed, and the jack is equivalent to the span of the column of the bending machine. When in use, one end of the steel bar is fixed, and the required spiral steel bar can be bent according to the general steel bar bending processing method.
Matters needing attention and quality requirements?
When the steel bar is bent, the bending point should be drawn, and the mark size should be deducted from the bending straightening value of the steel bar according to different bending angles and steel bar diameters. Scribing should be done on the workbench. If there is no scribing table, use a ruler to quantify the line directly, and use a wooden ruler with appropriate length to meet the quantity to prevent mistakes. After the first steel bar is bent and formed, it should be rechecked with the ingredient list, and batch processing should be carried out after rechecking meets the requirements. After forming, the steel bar should be in the correct shape, and there should be no concave curve on the plane. There is no crack at the bending point. The allowable dimensional deviation is: total length 10mm, stirrup side length 5 mm, stirrup side length 5 mm ...
Connecting joint of steel bar?
Welders must pass the examination and then go to work with certificates. Before rebar welding, a trial welding must be conducted according to the construction conditions.