Application conditions and control points of aluminum alloy template from the perspective of development

2022-05-05 0 By

Aluminum alloy templates were first applied in the United States in the 1960s.It has been introduced in China since the 1980s, but due to its high one-time cost, it has been seldom used for a long time.After 2006, with the rapid development of domestic high-rise super high-rise buildings, aluminum alloy template as a rising star in the template system, in line with the national “energy conservation and emission reduction”, “green building” and other policies, as well as the development of enterprises to implement the requirements of speed, so it can be quickly and widely used.Advantages of aluminum mold 1. Aluminum mold can effectively shorten the construction period, speed up the carry forward, reduce the time of capital occupation.Aluminum mold construction assembly and disassembly is quick, using early disassembly mold support system, through the use of a panel system + three sets of support system, can achieve 4~5 days of a layer of construction progress.For a 27-story house, the construction period of the main structure can be saved about 25 days compared to the traditional wood model construction.2. The aluminum mold has high strength and stability, and the concrete surface after demoulding has high flatness and precision, which can realize the surface free from plastering or thin plastering, saving cost and shortening construction period.3. Aluminum mold construction can reduce empty drum, cracking, leakage and other common faults, stair structural column, door and window lintel, sealing edge, caisson and other small size secondary components can be formed once, the effect is good, can effectively solve the leakage problems of external walls, doors and Windows, toilets and so on.4. Aluminum mold weight is light, only 20kg/m², can be manually handled, assembled and disassembled, without mechanical equipment assistance.Less on-site support, better construction environment, improve the working conditions of construction workers.5. Aluminum mold recovery and utilization ratio is high, and the average cost advantage is obvious.The normal usage turnover times is more than 300 times, and the salvage value recovery rate reaches 30-40%, which meets the national development requirements of energy saving, emission reduction, low carbon and environmental protection for the construction industry.6. Aluminum mold can be included in the score of assembly evaluation.Because of the advantages of aluminum mold construction, aluminum mold as a high-precision template can be included in the assembly evaluation score in some areas.1. The material cost of aluminum mold is higher than that of wood mold, and the one-time cost is larger. Therefore, the necessary condition for the application of aluminum mold is the need for a certain amount of turnover.2. If the facade moldings are too complex and there are differences between the upper and lower layers, it will lead to the complex processing and construction of aluminum molds, and increase the cost and construction period.Therefore, the design needs to improve the degree of standardization, simplify the facade alignment, for the use of aluminum mold fast construction conditions.3. The wall surface of aluminum mold construction is relatively smooth, leading to the hidden danger of falling off of the inner and outer wall tiles and insulation layer.When the facade is made of brick, the wall should be treated and reliable measures should be taken to prevent falling off.4. Aluminum mold combined with all concrete exterior wall can give full play to its advantages, but will cause an increase in the amount of structural materials.At present, in the construction of high-rise residential buildings in China, aluminum alloy template and wood template are widely used.The unit price of wood template is lower, but the turnover times are less;Aluminum mold unit price is high, one-time investment is large, but can turn over more than 300 times, so when aluminum mold turnover reaches a certain number of times, the amortized cost will be lower than wood template.Take a high-rise residential building as an example, the cost data of aluminum alloy formwork and wood formwork are compared as follows:Without considering the difference of plastering cost, when the total number of floors above ground is 27 (the total number of floors above ground = standard layers +2), the cost of the two is basically the same.Considering the cost advantage of aluminum mold without plastering, it is more economical to use aluminum mold when the total number of floors is more than 21.If the aluminum mold can be reused between different buildings, the overall economic benefits will be more obvious.When the aluminum mold as a high-precision template can be included in the assembly scoring item, the number of application layers of aluminum mold construction can be further reduced.Assuming that the aluminum mold score is calculated by 5 points, the assembly cost can be reduced by 20~30 yuan /m², and the number of aluminum mold application layers can be reduced to about 16 layers.The specific application can be determined according to the cost calculation of the project assembly scoring scheme.1. The use of aluminum mold construction can shorten the construction cycle of the main structure, aluminum mold and climbing frame, high precision block and other process methods combined to achieve the full professional intersperse construction, can greatly shorten the construction period, improve the overall economic benefits of the project.Before 2. All major construction is the construction of thrust through rational planning implementation facade decoration sync up with the main body structure construction, interior decoration, fine decoration with the main structure synchronization, garden followed the outdoor construction, finally realizes the subject, building plaster, doors and Windows, mechanical and electrical pipeline, indoor decoration, garden and so on all major construction.Taking the 27-story 80m high-rise residence as an example, the whole construction period can be shortened by more than 70 days while ensuring the reasonable construction period of single process, thus realizing the purpose of greatly improving efficiency.3. Influence and requirements of aluminum mold application on design cycle: The in-depth processing process of aluminum mold generally needs to go through the stages of drawing review, deepening processing drawings, production scheduling, trial assembly and coding, and transportation, etc. The total cycle takes about 50 days.Therefore, in order to meet the construction requirements of the standard layer and in combination with the standard period of civil construction, the design major needs to provide the engineering major with a full set of civil construction and hardcover construction drawings about 50 days before the construction of the standard layer.Design, engineering and further processing progress of aluminum mold Transverse chart Aluminum mold factory pre-assembly iv.To make the concrete members a molding and reduce the late a lot of water and electricity works at the open hole, slotted, aluminum mould with mould design needs to provide a complete set of civil engineering, water and electricity, fine decoration construction drawing, therefore the hardcover design unit should determine the hardcover point in construction drawing stage, in the aluminum mold design and processing stages, reserve a hardcover point accurately.2. In the process of in-depth aluminum mold design, engineering and design professionals should coordinate construction drawing design units, hardcover design units and aluminum mold manufacturers to communicate and answer questions.Through communication and answering questions, the “mistakes, omissions and defects” of various professional design drawings can be found as soon as possible, so as to avoid the impact of aluminum mold rework on construction efficiency and material waste.3. Aluminum mold and all concrete exterior wall are the “best partner”, the combination of the two can play the aluminum mold construction speed, interpenetration construction and many other advantages, in the application need to pay attention to the following points:(1) All-concrete exterior wall will increase the structural load of each layer by about 0.7-1.0kN /m². Before drawing pile foundation and foundation, it is necessary to check with engineering professionals to determine whether aluminum mold and all-concrete exterior wall are used.(2) When the whole concrete exterior wall is used, part of the secondary structure is poured together with the main body, which will lead to an increase in the amount of structural materials. It is necessary to communicate clearly with the contract cost professional in the early stage. The increment of steel quantity is about 2~4kg/m², and the increment of concrete is about 0.03~0.05 m3/m².(3) When the external wall does not need to adopt concrete wall in the structural calculation, the non-structural external wall and the wall under the window can be separated from the external wall in the form of structural tensile joints, so as to ensure that the external wall is cast in place and avoid the structure stiffness is too large, and the hidden leakage caused by secondary masonry can be avoided.(4) When there is a small wall stack at the edge of the door and window entrance, the structural steel bar can be set in the small wall stack, and the main structure of a casting molding, to avoid the small size of the wall stack building difficulties, and save the construction period.Door and window lintel is also changed to a hanging plate under the beam casting molding.4. Matters needing attention in the design of aluminum mold application: (1) Design standardization requirements:From the perspective of aluminum mold application, the development of enterprises to promote the application of standardized housing, can improve the degree of design standardization, shorten the deepening time of aluminum mold, at the same time can realize a set of aluminum mold in a number of buildings, large amortization of aluminum mold one-time investment, speed up, efficiency, cost reduction.(2) Line simplification requirements: the exterior wall design should reduce line decoration as much as possible.Simple modeling lines should be moulded together with the aluminum formwork system, complex modeling lines can be considered to be replaced by other lightweight materials, and reliable tie measures should be set between the main structure.(3) Design modulus requirements: aluminum mold is 50mm modulus, so the modulus of structure size is 50mm, to avoid the concave and convex components with small net distance of structure.The aluminum mold needs to be set separately for the wall thickness of non-modulus change, which leads to the increase of the cost of aluminum mold, so the change of the wall thickness of standard layer should be avoided as far as possible.(4) Building monomer length requirements: if the monomer is too long, it is necessary to set post-pouring belt or expansion strengthening belt to reduce the shrinkage and cracking of concrete during construction, but the post-pouring belt will greatly increase the number of supports and reduce the construction efficiency, so it is difficult to shorten the construction period by interspersing construction;However, the expansion reinforcement belt needs to set the upper steel bar in the floor slab, which leads to the increase of steel quantity and civil construction cost.Therefore, it is advisable to avoid the total length of a single unit exceeding 55m for high-rise residential buildings.(5) Building facade material requirements: aluminum mold finish surface is smooth, if the facade uses brick material, there is a risk of falling off in the later period, so the building facade as far as possible to choose coating materials.In addition, the selection of coating facade can accelerate the construction speed, which is conducive to the construction of other processes.(6) Minimum net distance requirement: In order to ensure the aluminum mold installation and construction, the minimum net distance between the two concrete walls should not be less than 700mm. If the equipment pipe well is adjacent to the concrete outer wall, if the net distance is less than 700mm, one side of the wall should be changed to masonry filled wall.Aluminum mold has many advantages in interpenetration construction, implementation of speed, material saving and environmental protection, assembly scores, and other aspects. At the same time, the application of aluminum mold has put forward higher requirements for the design profession: design standardization, design refinement, work in advance, professional circle.Only intensive cultivation can foster the strengths and circumvent the weaknesses, maximize the advantages of aluminum mold, while building high-quality building products, improve the overall benefits of the project.