Mooguzahn More by ACI Committee Considerations specific to architectural concrete are also outlined in a separate chapter. To download from the iTunes t, get iTunes now. Guide to Formwork for Concrete is available for download from Apple Books. Considerations specific to architectural concrete are also outlined in a separate chapter.
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Stivaros Kevin L. Wheeler Chair Secretary Rodney D. Adams Samuel A. Greenberg H. Lew Kenneth L. Berndt R. Kirk Gregory Donald M. Marks Randolph H. Bordner Awad S. Hanna Robert G. McCracken Ramon J. Cook G. Jum Horst William R. Phillips James N. Cornell Mary K. Hurd Douglas J. Schoonover Jack L. David David W. Johnston W. Thomas Scott William A. Dortch Roger S. Johnston Aviad Shapira Jeffrey C. Erson Dov Kaminetzky Rolf A. Spahr N. John Gardner Harry B. A section on contract documents explains the kind and Preface, p.
Separate chapters deal with design, construction, and materials for formwork. Considerations peculiar to architectural concrete 1. Other sections are devoted to form- 1. The 1. This 2. The Institute shall not 3. Reference to this document shall not be made in contract 3. If items found in this document are desired by the 3. ACI does not make any 4.
The user must determine the applicability of all regulatory limitations before applying the ACI supersedes ACI R and became effective October 15, Now comprising more than pages, this is the Chapter 5Architectural concrete, p. The Japan National Council on Concrete has 5. Therefore, each system is to be 5. Combining values from the 5. Chapter 6Special structures, p. This is believed to be 8. Many ACI Committee in , there had been an increase in of the terms can also be found in ACI R: the use of reinforced concrete for longer span structures, backshoresshores placed snugly under a concrete slab multistoried structures, and increased story heights.
The first report by the committee, based on a survey of construction loads from above. Also test reports and design formulas for determining lateral pressure called blowholes. The major result of this study and centeringspecialized temporary support used in the report was the development of a basic formula establishing construction of arches, shells, and space structures where the form pressures to be used in the design of vertical formwork.
Two subsequent revisions, of the structure. ACI R and ACI R, were committee reports climbing forma form that is raised vertically for because of changes in the ACI policy on the style and format succeeding lifts of concrete in a given structure. ACI returned the guide to the standard- diagonal bracingsupplementary formwork members ization process.
Note: Historically, the term has been the dimensions of footings, columns, and beams should applied to floor forming systems. Considering available sizes of dressed lumber, ply- ganged formslarge assemblies used for forming wood, and other ready-made formwork components vertical surfaces; also called gang forms. Preshores and the panels they support The structural design should be prepared simulta- remain in place until the remainder of the complete bay has neously with the architectural design so that dimen- been stripped and backshored, a small area at a time.
Variations in the installation of the reshores. Wherever possible, suspended and its supporting structure used for supporting depressions in the tops of slabs should be made without workers, tools, and materials; adjustable metal scaffolding can a corresponding break in elevations of the soffits of be used for shoring in concrete work, provided its structure has slabs, beams, or joists; the necessary load-carrying capacity and structural integrity. Embedments for attachment to or penetration through shoresvertical or inclined support members designed to the concrete structure should be designed to minimize carry the weight of the formwork, concrete, and construction random penetration of the formed surface; and loads above.
Avoid locating columns or walls, even for a few floors, slipforma form that is pulled or raised as concrete is where they would interfere with the use of large form- placed; may move in a horizontal direction to lay concrete for work shoring units in otherwise clear bays.
What reviews, approvals, or both will be required A well-written formwork specification tends to equalize a. For formwork drawings; bids for the work. Unnecessarily exacting requirements can b. For the formwork before concreting and during make bidders question the specification as a whole and make concreting; and it difficult for them to understand exactly what is expected.
Who will give such reviews, approvals, or both. They can be overly cautious and overbid or misinterpret 1. Some requirements can be required for the particular job or parts of it; written to allow discretion of the contractor where quality of Sequence of concrete placement, if critical; finished concrete work would not be impaired by the use of alternative materials and methods.
Tolerances for concrete construction; The live load and superimposed dead load for which the Consideration of the applicable general requirements structure is designed and any live-load reduction used. Requirements should be added for actual Intermediate supports under stay-in-place forms, such materials, finishes, and other items peculiar to and necessary as metal deck used for forms and permanent forms of for the individual structure.
Helpful and detailed information is given The location and order of erection and removal of in Formwork for Concrete. The basic geometry of such materials and such other features necessary to attain the objec- structures, as well as their required camber, should be tives. Special requirements for post-tensioned concrete When structural design is based on the use of commer- members.
The effect of load transfer and associated cially available form units in standard sizes, such as one-way movements during tensioning of post-tensioned members or two-way joist systems, plans should be drawn to make use can be critical, and the contractor should be advised of of available shapes and sizes. Some latitude should be any special provisions that should be made in the form- permitted for connections of form units to other framing or work for this condition; centering to reflect the tolerances and normal installation Amount of required camber for slabs or other structural practices of the form type anticipated.
Refer to Section 3. Formwork should also be the structural plans because they can play a key role in designed so that it will safely support all vertical and lateral the structural design of the form. Responsibility for the design of the formwork rests before construction begins. The amount of planning required with the contractor or the formwork engineer hired by the will depend on the size, complexity, and importance consid- contractor to design and be responsible for the formwork.
Formwork should be designed for 2. System stability and member ciencies that can lead to failure are: buckling should be investigated in all cases. Lack of allowance in design for loadings such as wind, 2. For example, Inadequate reshoring; wood forms are designed by working-stress methods recom- Overstressed reshoring; mended by the American Forest and Paper Association.
When Inadequate provisions to prevent rotation of beam forms the concrete structure becomes a part of the formwork support where the slabs frame into them on only one side Fig. Accordingly, in communication of the loads, it should be clear whether they are service loads or factored loads. Special provisions, such as safety, fire, drainage, and 2. The weight of formwork plus the weight of the does not relieve the contractor of the responsibility for reinforcement and freshly placed concrete is dead load.
The adequately constructing and maintaining the forms so that live load includes the weight of the workers, equipment, they will function properly. If reviewed by persons other material storage, runways, and impact. Refer to Section 2. When major design values and loading conditions should be shown motorized carts are used, the live load should not be less than on formwork drawings. Minimum values given for and connection details, formwork drawings should provide other pressure formulas do not apply to Eq.
For columns or other forms that can be Table 2. For columns: For walls with a rate of placement of less than 2. Accessory Safety factor Type of construction Imposition of any construction loads on the partially Form tie 2. Safety factors are based on the ultimate strength of the accessory when new. When fabricated formwork, shoring, or surge pressure.
In certain instances, pressures can be as high scaffolding units are used, manufacturers recommendations as the face pressure of the pump piston. For formwork for pressure should be considered when using external materials that will experience substantial reuse, reduced values vibration or concrete made with shrinkage compensating or should be used.
For formwork materials with limited reuse, expansive cements. Pressures in excess of the equivalent allowable stresses specified in the appropriate design codes or hydrostatic head can occur. Where there will be a 7. Wind loads on enclosures or other wind breaks attached to the formwork should be 2. Table 2.
SP-4 (14) Formwork for Concrete
ACI 347 giude to formwork for concrete.pdf