Source: Baidu Library aluminum alloy template is an important technology of energy saving and emission reduction in the construction industry, which can improve the construction efficiency and quality of housing construction, and has been widely applied in the current construction projects
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Generally speaking, the implementation process of aluminum formwork includes: detailed design → production → trial assembly → transportation → installation → removal
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This paper shares the application of aluminum formwork in the engineering example of China Construction Third Engineering Bureau, and introduces the construction technology, so as to provide reference for engineering friends
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For detailed design, aluminum formwork assembly drawing shall be further designed according to the architectural drawing, and the owner / Design Institute shall review and approve the design plan, template processing drawing, template assembly drawing and node detail drawing Production and production of aluminum mold in the factory production and production of profile blanking punching welding semi-finished products QC inspection and cleaning of aluminum mold finished products Trial assembly of aluminum formwork in the factory, and pre acceptance and adjustment by the owner / Design Institute / Supervisor in the factory Transportation system number, disassembly and packing, transportation to site, site handover Assembly and acceptance of installation site Dismantling and reuse The concrete surface effect is good
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Now let’s come to the construction site and focus on the installation and removal of aluminum formwork Aluminum formwork project selection requirements: aluminum alloy formwork shall be preferred for storey height
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The storey height shall be 2.8-3.2 meters, and the storey height shall be more than 3.2 meters
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The support mode shall adopt the traditional method plus cross bar and cross bracing
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The combination of outer frame aluminum formwork and outer climbing frame is the best construction method
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If the outer frame is cantilever frame, it needs special treatment in the template design, manufacturing and field installation, with high cost and increased construction difficulty
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The structural form of shear wall structure and frame shear wall structure is the best, and other structures have more masonry walls
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The advantage of using aluminum formwork is not obvious
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The shape structure has few lines, and the change is not complex
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The comprehensive economic single building is used for about 30 times, That is to say, it is first used in buildings with more than 30 floors
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Multiple buildings of the same structure, used more than 30 times in total Composition of aluminum mold system, formwork system, accessory system, pin, pin cup head, rubber tube pull screw, gasket K plate screw, support system, fastening system, diagonal hoist tie back ridge, material transfer hole Installation and installation process of aluminum formwork system: the sequence of aluminum formwork used upstairs: wall panel, beam panel, floor panel, support and others; All formwork shall be installed according to the drawing and number, no wrong installation or missing installation, wall plate installation, beam plate installation, flat plate installation, pole support, diagonal support installation Treatment of key and difficult points: at the lower opening of shear wall, the upper limit reinforcement is set around the wall column formwork, and the wall thickness positioning reinforcement is welded on the reinforcement; Install positioning rubber plug and rigid finished PVC pipe at the place where the screw is pulled
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Reinforce the hole
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Where the deviation is easy to occur, add a back ridge at the upper and lower parts of the door opening for reinforcement
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Internal angle treatment
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Verticality deviation is more common at the internal angle, The main bullet pin and fixed bolt of this part are strictly required to be no less than 2 on one side of each single formwork and the spacing is no more than 300 mm
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The installation requirements of starting board are as follows: (1) the embedded screws of starting board of exterior wall must be embedded firmly in the concrete of lower layer in advance, the spacing between two screws shall not be more than 1200 mm, and the single board shall not be less than 2（ 2) In addition to the embedded screws, there is also a row of screw rods pulling through the wall to prevent the balance and stability of starting（ 2) After the wall formwork is erected, the roller is used to brush oil
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In order to prevent the excessive flow of oil from polluting the ground, only the upper part of the formwork is brushed, and the lower part is allowed to flow evenly（ 3) The release agent of the floor part can not be painted by roller, but can only be sprayed by plastic pot, and the amount should not be too much Removal of aluminum formwork system
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According to the engineering experience, the formwork time of each part is as follows: about 24 hours, the wall column formwork can be removed, about 36 hours, the beam side formwork can be removed, about 48 hours, the beam bottom and plate bottom formwork (non load bearing) can be removed, about 12 days, the plate bottom bearing pillar can be removed, about 14 days, the beam bottom bearing pillar can be removed, about 28 days, and the cantilever pillar can be removed· Precautions for removal of aluminum formwork: 1
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Before removing the bottom formwork of aluminum alloy formwork, the concrete strength shall meet the requirements of the list
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2
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In order to ensure the quality of concrete, it is necessary to add three groups of cubic test blocks with the same curing strip during the construction of concrete pouring
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Before removing the bottom formwork, it is necessary to carry out the pressure test of this test block, or carry out the rebound instrument test on site
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After the strength meets the requirements in the table above, it can be removed after it is reported to the supervising engineer for approval· Removal of floor formwork and beam bottom formwork Prevention and treatment of common defects in aluminum formwork construction quality: the formwork is not passivated before use, and a large number of bubbles are produced on the concrete forming surface
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Prevention and treatment of cavity: 1:3 cement mortar is used in the factory or on site to brush the aluminum formwork contact concrete surface for 2 ~ 3 times, Make the surface of the formwork passivated
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Common faults: the sealing method of the lower opening of the formwork is wrong, which causes the broken column or the leakage of the slurry at the root of the column（ 2) Common faults: prevention and treatment of plane dislocation caused by not driving pin: (1) the bolts on the wall formwork must be fully driven according to the hole position requirements（ 2) Two components should be connected with at least two pins（ 3) Common problems: too large ridge and joint of formwork, which affect the appearance and quality of molding: (1) installation in strict accordance with the number（ 2) Repair the deformed formwork
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Common faults: when removing the formwork, the concrete at the edge of the line and falling plate is seriously damaged
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Prevention and treatment: use special formwork removal tools to control the formwork removal time according to the temperature
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Common faults: the floating slurry on the surface of the formwork is not cleaned up, which directly affects the splicing size and appearance of the formwork
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Prevention and treatment: after each formwork removal, it should be cleaned up, Clean up the laitance on the formwork surface, and brush the release agent before assembly The construction effect of aluminum formwork is analyzed.
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