In the construction and construction of water conservancy project, embedded parts can be divided into stress and structure of two kinds of embedded parts embedded parts, usually consists of two parts: 1, buried in the concrete anchor, the anchor bar generally use the I or II grade steel, can also use angle bars or other type of steel; 2, exposed in the anchor in the concrete surface, generally used in the 3# plate or angle etc..
In some parts the larger force, often in the anchor end baffle plate welding, called anchor plate, the purpose is to enhance the anchorage performance of steel. But for the requirements of shear the embedded anchor plate and welding in the shear plate, in order to meet the requirement.
In the construction and water conservancy project construction, embedded parts can be divided into two parts, embedded parts and embedded parts, usually composed of: Grade or grade II rebar, but also can use angle bars or other sections; ○ 2 anchor plates exposed on the concrete surface, generally use 3 # plate or angle steel.
In some embedded parts of a larger force, often at the end of the tendon welded baffles, called the small anchor plate, the purpose is to enhance the anchorage performance of steel. For the requirements of the embedded parts with shear, the anchor plate on the need to add welding shear plate to meet the requirements.
First, the preparation of embedded parts before construction
(1) The embedded parts construction process: ○ 1 steel, sheet metal processing; ○ 2 welding; ○ 3 mold and the installation of embedded parts; ○ 4 proofing against the construction drawings embedded parts size and location; ○ 5 pouring Concrete; 6 maintenance and demolition; 7 inspection of embedded construction quality; 8 repair.
(2) Before the embedded parts construction, should first understand the type, location and quantity, and then make and fix the embedded parts according to the standard requirements. The raw materials of the embedded parts should be qualified, must be checked before processing their certification, mechanical properties and chemical composition necessary to conduct the test, while the visual quality must be qualified, the surface no significant corrosion phenomenon. Reinforcing steel cutting and undercut sheeting, according to the size of the drawings carefully implemented. For the construction of embedded parts and embedded parts with special requirements, should pay attention to the length of the anchor bar hook, angle and other provisions.
(3) Before the embedded parts are welded, it is necessary to check whether the varieties of reinforced steel plates meet the design requirements and the mandatory standards. If they do not meet the requirements, they shall be identified and properly resolved.
(4) For the selection of electrode and flux type, according to its use requirements and different properties to be carried out, when the use of submerged arc welding, the use of the main metal strength suitable electrode; when using manual welding, should be the intensity Low main metal electrode model.
(5) The type of weld of embedded parts shall be determined by the size of anchor bars, and submerged arc welding with pressure bars of diameter> 20mm is preferred. When the construction conditions are limited, arc welding can also be used to select the appropriate type of weld Can guarantee the quality of embedded parts welding.
Second, the embedded parts of the welding method
Embedded parts of the welding submerged arc welding, welding arc, arc and top pressure and other links to be close at any time to clear the rust and debris at the jaws of the electric plate, while the shape of the electrode should be timely trim the notch. If you find the steel undercut, porosity, slag, steel welding wear, steel plate depression and other quality problems, need to identify the cause and promptly remove the welding defects. When using manual welding, fillet welding seam height to meet the standards. When using perforated plug welding, the hole of the steel plate should be made into a trumpet mouth, the diameter of the inner mouth should be 4mm larger than the diameter of the reinforcing bar, the lean angle of one muscle should be 45, the end of the reinforcing bar should extend to about 2mm of the steel plate, special attention should be paid to the strict control Current capacity, to prevent burns rebar.
Third, embedded parts fixed method
Embedded parts fixed position is an important part of embedded parts construction, embedded parts are located in different positions, the effective selection of the fixed method is also different.
(1) When the embedded parts are on the top surface of cast-in-place concrete, there are several fixing methods according to the sizes and functions of the embedded parts: ○ 1 Small size of the embedded parts of the flat type can be directly bound with the embedded parts In the main reinforcement, but in the process of pouring concrete, the need to observe the position at any time, in order to solve problems promptly after; ○ 2 angle steel embedded parts can also be directly tied to the main reinforcement, in order to prevent concrete under the embedded parts vibrate not Dense, should be fixed before drilling holes in the embedded parts for the construction of concrete exhaust; ○ 3 large area embedded parts construction, in addition to the anchoring ribs fixed, but also in the upper part of the appropriate specifications of spot welding angle, To prevent the displacement of embedded parts, if necessary, drill holes in the anchor exhaust. For extra large embedded parts, drilling pounding holes shall be drilled in the anchor plate to vibrate the concrete. However, the position and size of the drilling holes shall not affect the normal use of the anchor plate.
(2) When the embedded parts are located on the side of concrete, the following methods are available: ○ 1 When the embedded parts are shallower and smaller than the concrete surface, the fasteners can be fastened by bolts to fix the embedded parts to the formwork, ; ○ 2 When the area of the embedded parts is not big, the pre-perforated embedded parts can be fixed on the wooden stencil by ordinary nails or wood screws.
Fourth, the embedded parts installed
(1) Position the longitudinal and transverse axes of the bolt on the surface of the cushion according to the size of the design drawing, and take the axial post on the outside of the foundation. And the axis of the basic template to be marked on the outside of the logo, the use of the template surface with a hacksaw blade or blade vertical vertical scratches in the template drawn inside, with red (or yellow) color paint markings buried parts, embedded parts number Use the same method on the template logo.
(2) Before installing the anchor bolts, first complete the assembly of 4 (6) bolts for each group of bolts, that is, install a Φ10 stirrup at the bolt roots and around -0.4m, Hole template template, check the template level, and use the upper and lower nut tighten the template. Bolt lower level to be in the same plane, the spot welding bolts and stirrups to form a bolt cage, stirrup and bolt template are drawn two-way axis (center line), and should be re-and control.
(3) After the bracing of the two-way main reinforcement at the bottom of the base plate is completed and the bolts are arranged one by one according to the positions of the embedded parts, the bidirectional axes of the bolts are matched with the bidirectional axes on the cushion and the template, 45 ° to do the four corners of the diagonal braces, the upper part of the braces and bolts welded fixed, the lower part of the main welding with the main plate fixed. Each group of bolts, with a hole template or wooden side even into a whole and review accurate. Sub-group bolts installed after the inspection, by the team technician construction drawings and pull the rod to check, correct, acceptance. Sub-group bolts installed after the school inspection, and then the overall re-examination of all bolts, check. In the re-inspection process, if you find excessive deviation, must be promptly corrected. After the embedding bolts are checked, they shall be reported to the inspection department of the project department and the supervision department for review and approval of the qualification. After the opening identification and the application form for concrete pouring are issued, the first construction concrete pouring shall be carried out. The second construction section according to the same operating procedures for construction.
(4) The upper part of the HM steel and 22 thick steel plate embedded parts, after the first concrete pouring is completed, the determination of steel axis and elevation, with a nut leveling, the surface elevation error within 2mm, repair box based 4 M -2 iron installation easier, but must strictly control the top elevation, flatness and axis position.
(5) The top of the cable trench dipped galvanized angle steel: the height of the upper surface of the angle gauge measured in the cable ditch side mold, marked on the template, the horizontal point of about 800-1000 set point. After the wood screws through the pre-drilled holes on the angle, according to the copy level will be fixed on the template.
(6) Foundation After the first concrete pouring, the technician should carry out the spring wire of the second embedded part. The center line of each embedded part should be detected by the axial post outside the base, and the relative position of the embedded parts should be checked emphatically And the relative position of the entire group of embedded parts. At the same time bomb line, the embedded bolt is pouring in the position, the team technical staff to review, adjust. After the completion of the project by the Ministry of Quality Supervision, Inspection and Supervision Department to conduct inspections.
Fifth, the inspection and acceptance of the results of the operation and should meet the standard requirements
(1) Embedded parts processing and installation of the deviation of the allowable position
(2) Drilling Bolt Holes on HM-200 * 200 Steel: Pitch Loft, Cross Section Deviation of Model, Pitch and Axis Distance ≤ ± 0.5mm
(3) Weld around the weld must be straight, no bite meat, slag, leak welding.
(4) galvanized surface should be smooth, no falling.
(5) Embedded parts installation center line deviation control ≤ ± 3mm
(6) embedded surface installation of the level of control in ≤ ± 2mm
(7) Embedded parts installation surface elevation control ≤ ± 2mm
(8) The basic concrete surface elevation control ≤ ± 5mm
Sixth, construction precautions
(1) It is strictly forbidden for operators to step on and tread the steel bar with smaller diameter to ensure the steel bar frame will not be deformed. Pay attention to product protection and cooperation between the various processes and convergence.
(2) The operator shall not bring oily dirt, mud and other impurities into or stay in the steel framework. If found to be promptly cleared.
(3) Bolt must be protected. Do not hit the bolt, so as not to bolt the wire mouth deformation, which led to the installation ended.
(4) The embedded parts should pay attention to the protection of the unloading parts and shall not cause the scratches and deformation caused by unloading. Embedded parts must be stacked to prevent contamination or damage.
Seventh, safe operation content and requirement
(1) Reinforced welding, cutting operator must wear masks, gloves and eye protection to prevent welding light or iron slag injury.
(2) before using the electric tool must check the line and the use of equipment in good condition, to prevent electric shock.
(3) Pay attention to the steel reinforcement head put on the cushion when walking on the bottom rib to prevent scratches and tripping injuries.
(4) should be less moving cable to prevent the cable insulation has been damaged, the occurrence of electric shock wounding.
(5) The site must be properly equipped with helmets, cross-work must be coordinated with each other, pay attention to safety.