Erection method and requirements of full hall scaffold
1 The bamboo plywood cushion block used under the full hall frame should be made of leftover materials. The production specification is 200 200mm. It is strictly prohibited to use large formwork
2. The distance between the upright poles of the full hall frame is l 800mm, and 48mm steel pipes are erected. There shall be no less than 3 horizontal poles, one floor sweeping, one middle pole and one beam bottom pole. And add diagonal bracing
3. Integrity and stability structure of the frame:
1) Vertical pole: the frame is equipped with vertical and horizontal sweeping poles, which are set on the vertical pole 200mm above the foundation plane and fixed on the vertical pole with cross fasteners
. Two way horizontal poles must be set between the vertical poles according to the step distance to ensure sufficient design stiffness in both directions. The vertical pole joints should be wrong and should be completely removed and not set on the same level. A wooden wedge should be added between the lower end of the vertical pole and the skid to adjust the uneven settlement of the vertical pole
2) horizontal bar: the vertical and horizontal horizontal bars are fixed on the vertical bar with right angle fasteners, the tightening torque of the fasteners is controlled at nm, and the horizontal bar must be crossed at the corner (forming a well shaped structure); When the horizontal bar is extended, the two adjacent joints are not in the same span synchronously. For asynchronous and different spans, the staggering distance between the two joints in the height direction should not be less than 500 mm
3) wall connecting rod:
the frame body is effectively connected with the concrete frame column to improve the deformation capacity of the formwork support under the construction load
4). Diagonal bracing setting:
vertical diagonal bracing: set diagonal bracing all around the upright bar outside the formwork support; Vertical diagonal bracing is set in the middle every 7.5 ~ 9.0m; The vertical and horizontal diagonal bracing shall be set according to three steps and six spans
horizontal diagonal bracing: when the height of the support frame is 20m, every 6.0 ~ 7 in the top and middle of the frame At present, many 3D printing material enterprises in China set horizontal diagonal bracing at 5m to improve the stability of the frame when resisting the impact of horizontal construction load; In any case, horizontal diagonal bracing must be set at the top and bottom of the high support
5). The rows of support frames around the middle hall will not be removed after the construction of each layer, and will be used as the auxiliary frame of the flower frame beam formwork of the water tank roof, so as to facilitate the overall stability of the flower frame beam formwork. The unloading frame on the first floor of the middle hall is vertically corresponding to the upright pole of the formwork support on the above floors, and a 50mm thick and 250mm wide wood board is placed under the upright pole. Requirements for beam formwork erection and details:
1) beam bottom formwork, first calculate the height of the beam bottom and the camber height. After leveling according to the elevation of the beam bottom, connect the beam to fix both ends horizontally, and then draw a through line to fix the middle horizontal pole, with a fixed spacing of no more than 800mm, and place it in advance according to the beam width. Place the beam bottom plate on the fixed shelf, straighten the wire rope, erect the binding plate, erect the binding plate on the 10cm square timber, nail the square timber on the beam board, lock the binding plate with steel pipe and horizontal rod, and the upper mouth is connected with the horizontal steel pipe of the flat plate. If the beam is larger than 750mm, the opposite tie rod must be used, and the top plate can be laid after the beam binding correction and reinforcement
2) the formwork joints shall be free of mortar leakage, and the contact surface between the formwork and concrete shall be cleaned and coated with release agent. However, it is not allowed to stain the reinforcement or concrete
3) formwork inspection standard: the axis displacement is within 3mm. The elevation is within 5mm, and the section size is within 34. The verticality is within 2mm, and the flatness is within 3mm
3 formwork removal
1) priority should be given to the removal of formwork one by one. Stacking and turnover of the whole room. Avoid confusion
2) the edges and corners shall not be damaged during the removal of binding formwork of columns and beams
3) the strength of beam bottom and top plate shall reach 75%. For members with a span of more than 8 meters, the concrete strength must reach 100%
4) when dismantling the beam bottom and top plate, the steel keel should be lowered to 10~20 cm, and it will not be removed temporarily. Dismantle the wooden keel and bamboo plywood on top and hand them down one by one
5) when removing the formwork, the surrounding areas should be protected with dense eyes or bamboo plywood to prevent objects from falling and hurting people
6) the removed formwork shall be cleaned in time and coated with release agent. The removed fasteners and fashion bags shall be collected and managed centrally
4
1) when hoisting the formwork, handle it gently and do not collide with it to prevent the formwork from deformation
2) do not use a sledgehammer to smash or pry hard when removing the formwork, which is not only easy to damage the formwork, but also easy to damage the concrete surface
3) for the column after formwork removal, wrap the column with angle bead to avoid damaging the column concrete corner during erection. The stair steps are the same
5 attention should be paid to the quality problems that are easy to occur in the formwork construction:
a) problems that are easy to occur in the column formwork: inaccurate section size, column position displacement, column bending. The method is as follows: before formwork erection, snap the position line according to the drawing, and use wooden strips around to top it (leaving the thickness of the plate) to ensure the accuracy of the bottom position. The formwork prepared according to the cross-sectional size of the column is backed with square timbers around, and the four sides are hung upright, hooped and locked, and then the support is pulled around
b) problems easily caused by the beam slab formwork: the beam Bang is uneven, the beam bottom is uneven, and the beam mouth is not smooth and straight. The prevention methods are: the beam slab formwork is supported, and the spacing of the keel should be calculated to ensure its strength, stiffness, and the horizontal bar of the bottom formwork should be arched according to the design and specification requirements, and the line should be pulled to lock the beam mouth to prevent deformation on the mouth
large formwork for shear wall
1. For the construction of large formwork, the large formwork of the project is designed and configured with a standard floor, and the slab height is 4.72 meters. The height of the first floor is 5.95 + 1.6 meters, the height of the floor is 7.55 meters, and the first pouring height of the formwork is 2.7 meters. When pouring concrete, the elevation control is less, and the grouting is mainly used to control the height and flatness. The secondary height is 4.72m, and it is poured to the top at one time
construction procedure: Foundation setting out, reinforcement binding, formwork erection, verification, pouring concrete
2, wall formwork
2.1 according to the needs of construction technology and the effect of fair faced concrete wall, the project adopts Yutian system 86 assembled all steel large formwork; Each assembled formwork is composed of several marking unit plates. In order to ensure the rigidity of the large formwork, the formwork panel adopts the original flat plate of = 6mm, and the main rib adopts paired 10 channel steel, and three longitudinal channels are set. Five rows of through wall bolts shall be set longitudinally for the internal and external wall formwork, and the horizontal spacing shall not be greater than 1200mm
through wall bolts, outriggers and outriggers are essential components of the formwork. The through wall bolt adopts the large head 32mm, small head 28mm, conical, galvanized part, and is equipped with anti ash sleeve and special clamp head; The front end of the socket is hexagonal female, which can be operated with a wrench; The back end of the sleeve is punched with a 18mm round hole, which can be inserted and rotated with round steel. The components are reliable in connection, convenient in disassembly and high in turnover. At the same time, a rubber sleeve (only for sale) is equipped between the through wall bolt and the large formwork to prevent the leakage of cement slurry from the through wall hole during concrete pouring, improve the concrete quality and surface finish, and provide a perfect guarantee for ensuring the construction quality
in view of the high formwork configuration of this project, the original large formwork legs are not easy to use. The correction requires the support pipe, jacking, steel wire rope and basket bolt as the supporting and strengthening facilities. The reinforcement pull ring should be embedded around the shear wall in advance as the supporting and fixing point
the cantilever, that is, the operation platform, is welded with ¢ 48mm steel pipes. China's graphene, known as "universal material", is still in the early stage of industrialization practice. It is fixed on the large formwork with the connecting hole on the vertical rib and paved with wood plates, which can be used for pouring concrete operation platform
2.2 wall formwork configuration
formwork configuration height:
inner plate height: 2920mm; Connecting height: 1850mm
outer plate height: 2920mm; Heightening: 1850mm
according to the structural characteristics of the outer wall circumference of the project, the outer wall circumference is fully equipped with a 200mm high hanging formwork. The advantages of the method of configuring the hanging formwork are that it avoids the pouring of the guide wall, solves the problem of mortar leakage between layers, and there is no difference between the internal and external wall formwork, which can be used interchangeably, which not only reduces the formwork investment, but also improves the construction efficiency
according to the requirements of the construction party, the large formworks at the door and window openings are all disconnected, and the coupling beams constructed together with the wall are equipped with beam formworks, which include: beam side formworks, beam bottom formworks, and blocking plates under the beam. The method of configuring beam formwork can effectively ensure the position, size and pouring effect of door and window openings, but this configuration method takes up too much time of tower crane, which affects the progress of high-temperature gas expansion first. Moreover, due to the disconnection of the formwork at the hole, there are many formwork plates, and the verticality is not well controlled during the formwork erection process. The existence of other special openings will make the formwork erection very cumbersome. Therefore, we suggest that in order to ensure the straightness of the external wall door and window openings, all the external wall door and window openings should be disconnected, and the internal wall should adopt the built-in formwork configuration method to improve the formwork erection efficiency
the staircase formwork is configured according to the height of the external wall formwork. The exterior wall decoration edge, window sleeve, air conditioner board (refers to the elevation that is not the same as the top plate) adopt the post pouring method
2.3 angle formwork
angle formwork includes internal angle formwork, external angle formwork and special-shaped angle formwork. There is a 2mm gap between the internal angle formwork and the large formwork, and there is no gap between the internal angle formwork and the large formwork. The frames are connected by special connectors or bolts
in order to reduce the lifting times of tower crane, improve the construction efficiency and ensure the pouring effect of concrete. The corner formwork and small formwork are designed as a whole in some special parts; Namely: Z, W, l and other shapes. Connectors and small back ridges are used for reinforcement between special-shaped angle formwork and large formwork. The large shaped angle formwork is reinforced with through wall bolts
2.4 node treatment method
between the internal corner formwork and the large formwork, through special connecting bolts and multiple internal corner pressing grooves, the phenomena of staggering and distortion are effectively controlled to ensure the smoothness and straightness of the concrete wall after pouring. The flat joint between the large formwork and the external corner formwork is connected with special connectors or bolts, and three right angle back ridges are set longitudinally to effectively ensure that the external corners are straight and smooth
2.5 treatment of T-shaped wall
the configuration of the large formwork at the T-shaped wall is either too large cantilever or configured with a blocking plate, and they are not directly reinforced by through wall bolts. At this time, in addition to using the connection at the frame, additional reinforcement measures should be taken, using the large back edges of the large formwork on both sides, clamping the special small back edges into the large back edges, and then pulling the through wall bolts, so that the adjacent large plates are connected as a whole, Effectively avoid the mold expansion problem of this part
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