The Reorganized ACI 14 Code. – Are You Ready? Neal S. Anderson, P.E., S.E.. Staff Consultant. Simpson Gumpertz & Heger, Chicago, Illinois. The American Concrete Institute (ACI) has pub- lished Building Code Requirements for Struc- tural Concrete (ACI ) and Commentary. /R ACI Building Code and Commentary. PREFACE. The code portion of this document covers the design and construction of structural concrete .
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These friction losses shall be calcu- lated: Curvature friction — Friction resulting from bends or curves in the specified cable profile. Although they may give somewhat different results in details, the re- sulting floors give reasonable over-all safety factors. Such stirrups or ties shall be used throughout the distance where the compression reinforcement is required. ACI standards and recommendations “Building Code Requirements for Reinforced Concrete” are minimum standards of performance in legally enforceable phraseology.
The area of reinforcement shall be determined from the bend- ing moments at the critical sections but shall be not less than re- quired by Section Where the load to be supported is definitely known, the structure shall be analyzed for that load.
The strength at transfer shall be adequate for the require- ments of the anchorages or of transfer through bond as well as meet camber or deflection requirements. For symmetrical spiral columns: The numerical sum of the positive and negative bending moments in the direction of either side of a wci panel shall be assumed as not less than in which F — 1.
The Code also acu the strength evaluation of existing concrete structures.
A column strip one-half panel in width, occupying the two quarter- panel areas outside the middle strip. Except as provided herein, all welding shall conform to AWS D In bars required for compression only, the compressive stress may be transmitted by bearing of square-cut ends held in concentric contact by a suitably welded sleeve or mechanical device.
The shear is not over half that normally permitted, including allowance for shear reinforcement, if any.
The test load shall not be applied until the structural members to be tested have borne the full service dead load for at least 48 hr. A middle strip one-half panel in width, symmetrical about panel ac line and extending through the panel in the direction in which moments are considered.
Portions exposed above grade shall, in addition, be reinforced with not less than the amount specified in Section This Board shall be composed of competent engineers and shall have the authority to investigate the data so submitted, to require tests, and to formulate rules governing the design and construction of such sys- 3318-10 to meet the intent of this code. Wobble friction — Friction caused 31810 the unintended deviation of the prestressing steel from its specified profile. The change in length of columns and slabs due to direct stress, and deflections due to shear, may be neglected.
Brackets capable of transmitting the negative bending and the shear in the column strips to the columns without excessive unit stress may be substituted for column capitals at exterior columns. Web rein- forcement between the face of the support and the section at a distance d therefrom shall be the same as required at that section.
Unless otherwise provided, the bending moments at the criti- cal sections of the column and middle strips shall be at least those given in Table f.
Required splices in bars may be made wherever convenient, but preferably away from points of maximum stress. All stirrups so required shall be anchored into the cast-in-place slab, where their area may also be relied upon to provide some or all of the vertical tie steel required in c.
318-08: Building Code Requirements for Structural Concrete and Commentary
Soil pressures shall be considered as acting uniformly or vary- ing linearly, except that other assumptions may be made consistent with the properties of the soil and the structure and with estab- lished principles of soil mechanics. Spiral bound to lie flat. Elongation requirements shall be taken from aver- age load-elongation curves for the steel used.
A tension bar may be anchored by bending it across the acu at an angle of not less than 15 deg with the longitudinal portion of the bar and making it continuous with the reinforcement on the opposite face of the member.
The radius of gyration, acii, may be taken equal to 0. Users are free to copy, use, and redistribute the work in part or in whole. Splices of wires stressed at not more than one-half the per- missible stress shall be so made that the overlap measured between outermost cross wires is not less than 2 in.
This strength may be demon- strated by job-cured test specimens and by a structural analysis con- sidering the proposed loads in relation to these test strengths. At least 50 percent of the required negative reinforce- ment in the column strip shall cross the drop panel, if any. The Commentary is provided for this purpose. All piping and fittings shall be tested as a unit for leaks im- mediately prior to concreting. This reinforcement shall be designed to carry the load on the portion of the slab required for the flange of the T-beam.
Bonded tendons — Tendons which are bonded to the concrete either directly or through grouting. Items of a more general nature are indicated by page numbers in normal weight type In the case of the reinforcement in the short direction, that portion determined by Eq.
Balanced conditions exist when, at ultimate strength of a member, the tension reinforcement reaches its yield stress just as the concrete in compression reaches its assumed ultimate strain of 0. Effective area of concrete—The area of a section which lies between the centroid of the tension reinforcement and the compression face of the flexural member. The maximum pressure to which any piping or fittings shall be subjected shall be psi above atmospheric pressure.
The Building Official may require a reasonable number of additional tests during the progress of the work.
Building Code Requirements for Structural Concrete and Commentary
Concrete—A mixture of portland cement, fine aggregate, coarse aggre- gate, and water. In concrete joist floors in which the clear distance between joists is not more 318-100 30 in. Where slabs are thus analyzed separate- ly, it may be assumed in determining the bending at a given sup- port that the slab is fixed at any support two panels distant there- from provided the slab continues beyond that point.
Shrinkage of concrete 5.
Slabs where plain bars are used 0. Provision shall be made for transfer of shear and other forces through the construction joint. Where no capital is used, the face of the column shall be con- sidered as the edge of the capital. Where the exterior supports provide only negligible restraint to the slab, the values of tx and t2 for the ack panel shall be increased by at least 15 percent.
Cross grain compression 8. The equivalent of the bars so interrupted shall be provided by extra steel on all sides of the opening. In calculations of section properties prior to bonding of ten- dons, areas of the open ducts shall be deducted.