PDF will make you easier to get what book that you really want.. Users will find information for design suggestions and material properties. This edition has come updated and revised to contain a wealth of essential information for both veteran designers and novices in order to improved safety, quality and economy in all types of formwork. Aci r 14 Guide To Formwork For Concrete r 14 guide to formwork for concrete, aci chapter guide; chapter annual r 14 guide to formwork for concrete your price..
The American Concrete Institute disclaims any and all. ACI SP-4 Formwork For Concrete 8th Edition serves a broad range of information needs with the objective of improving quality, safety, and economy in all types of formwork.
ACI R — provides guidance related to contract documents, the selection of formwork, use of formwork, the reference document for design architects, … Download aci sp 4 pdf Art and craft books online, The text has been revised for consistency with the report of Committee , Guide for Formwork for Concrete ACI R , which is reprinted completely in the appendix. Keywords: architectural concrete; construction … sp 4 8th formwork for concrete Download sp 4 8th formwork for concrete or read online here in PDF or EPUB.
Please click button to get sp 4 8th formwork for concrete book now. Free shipping for many products! Concrete and Formwork: Performed by company experienced for five 5 years minimum in construction of top quality, site cast concrete work, familiar with and capable of producing concrete work in accordance with referenced standards listed in Paragraph 1.
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 5—Architectural concrete, p. The Japan National Council on Concrete has 5.
Therefore, each system is to be 5. Combining values from the 5. Chapter 6—Special 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, backshores—shores 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 centering—specialized 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 form—a 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 bracing—supplementary formwork members ization process. Note: Historically, the term has been the dimensions of footings, columns, and beams should applied to floor forming systems.
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.
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. 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.
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. 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. Accordingly, in communication of the loads, it should be clear whether they are service loads or factored loads.
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. When fabricated formwork, shoring, or surge pressure. 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. For wall the loads transmitted to the floors, shores, and reshores or forms exposed to the elements, the minimum wind design backshores as a result of the construction sequence.
All structural members and connections should be carefully planned so Commercially available load cells can be placed under that a sound determination of loads may be accurately made selected shores to monitor actual shore loads to guide the and stresses calculated. If plywood or used to support formwork and other construction loads.
It lumber splices are made for timber shoring, they should be should be kept in mind that the strength of freshly cast slabs designed to prevent buckling and bending of the shoring. Before construction, an overall plan for scheduling of Formwork failures can be attributed to substandard materials shoring and reshoring or backshoring, and calculation of and equipment, human error, and inadequacy in design.
The plan and responsi- Construction procedures should be planned in advance to bility for its execution remain with the contractor. Some of the safety provisions that should 2. Horizontal lacing can be considered displacement or failure. A supply of extra shores or in design to hold in place and increase the buckling strength other material and equipment that might be needed in of individual shores and reshores or backshores. The braced system should be anchored to ensure all forms that will be crane-handled.
This is especially stability of the total system. In the case of wall formwork, consideration should be given to an 2. No concrete should be fall protection devices, such as personal fall arrest systems, placed on formwork supported on frozen ground. Lacing to reduce the shore slenderness ratio can be to Fig. All threads should fully work include: engage the nut or coupling. By doing this, each supported directly on the formwork or structural member. The formwork at control joints should be left undisturbed when forms are should be suitable for the support of such runways without stripped and removed only after the concrete has been significant deflections, vibrations, or lateral movements.
Wood strips inserted for architectural 3. Loads, such as aggregate, 3. Suggested toler- 3. Specifying tolerances more exacting than needed can work drawings. Both before each use. If surface appearance is important, forms should ances are not specified or shown. Specifying tolerances more stringent 3. For example, specifying permitted 3. Where a project involves to damage or overload it. Improper positioning of shore from floor to floor can create bending stresses for which the slab was not designed.
Table 3. In measuring irregularities, the straightedge or template Class of surface can be placed anywhere on the surface in any direction. The project specifications should Class C is a general standard for permanently exposed clearly state that a permitted variation in one part of the surfaces where other finishes are not specified. Class D is a construction or in one section of the specifications should not minimum-quality requirement for surfaces where roughness be construed as permitting violation of the more stringent is not objectionable, usually applied where surfaces will be requirements for any other part of the construction or in any permanently concealed.
Special limits on irregularities can other such specification section. If permitted irregularities are nating the tolerances for concrete work with the tolerance different from those given in Table 3.
Allowable stresses and punching shear. The reversal of stresses results irregularities are designated either abrupt or gradual. Offsets from the reversal of bending moments in the slab over the and fins resulting from displaced, mismatched, or misplaced shore or reshore below as shown in Fig. Where the forms, sheathing, or liners, or from defects in forming materials conditions are questionable, the shoring location should be are considered abrupt irregularities.
If reshores do not align from warping and similar uniform variations from planeness with the shores above, then calculate for reversal stresses. Reshores should be 3.
The strength can be determined Where a slab load is supported on one side of the beam only by tests on job-cured specimens or on in-place concrete. Inclined shores should be should be correlated to the actual concrete mixture used in braced securely against slipping or sliding. The bearing ends the project, periodically verified by job-cured specimens, of shores should be square.
Results of such tests, as well as records of the forms refer to Fig. Depending on the generally accomplished by the use of sand boxes, jacks, or circumstances, a minimum elapsed time after concrete place- wedges beneath the supporting members. For the special ment can be established for removal of the formwork.
When forms are removed before the specified curing is completed, measures should be taken to continue 3. Supporting forms and shores should not be concreting can be found in Reference 1. In no case should supporting 3. Formwork and 3. When stan- dead load deflections of form members. The curing records can 3. The times shown represent a cumulative number Over 20 ft 6 m clear span of days, or hours, not necessarily consecutive, during between structural supports If high early-strength concrete is Under 10 ft 3 m clear span used, these periods can be reduced as approved by the engi- between structural supports Shorter stripping times listed for live between structural supports Removal times are contingent more reserve strength being available for dead load in on reshores where required, being placed as soon as practi- absence of live load at time of stripping.
As soon as full post- Structural live Structural live tensioning has been applied. Under 10 ft 3 m clear span reshores—shores placed snugly under a stripped concrete between structural supports It is assumed that the reshores Reshoring is one of the most critical operations in form- carry no load at the time of installation.
Operations Multistory work represents special conditions, particularly should be performed so that areas of new construction will in relation to the removal of forms and shores. Reuse of form not be required to support combined dead and construction material and shores is an obvious economy. Furthermore, the loads in excess of their capability, as determined by design speed of construction in this type of work permits other load and developed concrete strength at the time of stripping trades to follow concreting operations from floor to floor as and reshoring.
The shoring that supports freshly placed Shores should not be located so as to alter the pattern of and low-strength early-age concrete, however, is supported stress determined in the structural analysis or induce tensile by lower floors that were not originally designed specifically stresses where reinforcing bars are not provided. Size and for these loads.
The loads imposed must not exceed the safe number of shores, and bracing, if required, should provide a capacity of each floor providing support. For this reason, supporting system capable of carrying any loads that could shoring or reshoring should be provided for a sufficient be imposed on it.
When shores above are not used to distribute construction loads to the lower floors. This condition seldom occurs in reshoring weight of only the new slab plus other construction live because the bending stresses normally caused by the offset loads.
The weight of intermediate slabs is not included reshores are not large enough to overcome the stress because each slab carries its own weight before reshores are resulting from the slab carrying its own dead load. Where put in place. The slabs interconnected by reshores will excessive punching shear or bending stress in the slab.
Loads will While reshoring is under way, no construction loads be distributed among the slabs in proportion to their developed should be permitted on the new construction unless the new stiffness. The deflection of concrete slabs can be considered construction can safely support the construction loads. Caution should When placing reshores, care should be taken not to preload also be taken when a wood compressible system is used. Such the lower floor and not to remove the normal deflection of systems tend to shift most of the imposed construction loads to the slab above.
The reshore is simply a strut and should be the upper floors, which have less strength. Addition or removal tightened only to the extent necessary to achieve good of loads may be due to construction activity or to removing bearing contact without transferring load between upper and shores or reshores in the system.
Shore loads are determined by lower floors. Removal operations should be carried out in accordance with Slabs are allowed to support their own weight, reducing the a planned sequence so that the structure supported is not load in the reshores.
Combination of shores and reshores subject to impact or loading eccentricities. The design and placement of shores and reshores for 3. The stressing of post- original shores in place or replacing them individually back- tensioning tendons can cause overloads to occur in shores, shoring and preshoring , which prevents the slab from reshores, or other temporary supports.
The stressing sequence deflecting and carrying its own weight. These methods are has the greatest effect. When a slab is post-tensioned, the force not recommended unless performed under careful supervision in the tendon produces a downward load at the beam. If the floor slab is 3. In general, it consists of an inside tensile required in the finished product. These manufacturers also documents, should be based on how the quality of materials publish recommended working loads on the ties for use in affects the quality of finished work.
Where the concrete surface form design. Their suggested working loads range from ups. The advent of flexible moulds, however, marks a radical break from conventional practice — and conventional concrete architecture. The Fabric Formwork Book provides the first comprehensive handbook on the emerging technology of flexible moulds for reinforced concrete architecture.
Written by the foremost expert in the field, this book takes a comprehensive and generous approach that includes technical, historical and theoretical aspects of the subject. The book: concentrates on simple flat-sheet formworks contains detailed technical descriptions of how to construct a wide range of formworks for various applications features case studies from around the world critiques the difficulties and advantages in each case it covers provides instruction and guidance on how to model and design fabric-formed structures includes the most comprehensive history of fabric formwork yet published features essays from guest expert authors, which explore the theoretical, historical, and poetic significance of flexibly formed architecture and structures discusses fabric formwork as an exemplary approach to sustainable construction through its simplicity and efficiency.
Beautifully designed and illustrated with a superb range of images, diagrams and technical drawings, the book both informs and inspires.
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