ACI_349-01

134 Pages·02.913 MB·English

ACI 349-01
Code Requirements for Nuclear Safety Related
Concrete Structures (ACI 349-01)
Reported by ACI Committee 349
Charles A. Zalesiak
Chairman
Hans G. Ashar Gunnar A. Harstead Richard E. Klingner
Ranjit Bandyopadhyay Christopher Heinz Dragos A. Nuta
Ronald A. Cook Charles J. Hookham Richard S. Orr
Branko Galunic Ronald J. Janowiak Barendra K. Talukdar
Herman L. Graves III Jagadish R. Joshi Donald T. Ward
Albert Y. C. Wong
This standard covers the proper design and construction of concrete cracking (fracturing); creep properties; curing; deep beams; deflec-
structures which form part of a nuclear power plant and which have tion; drawings (drafting); earthquake resistant structures; edge
nuclear safety related functions, but does not cover concrete reactor
beams; embedded service ducts; flexural strength; floors; folded
vessels and concrete containment structures (as defined by ACI-ASME
plates; footings; formwork (construction); frames; hot weather con-
Committee 359).
struction; inspection; joists; loads (forces); load tests (structural);
The structures covered by the Code include concrete structures inside
mixing; mix proportioning; modules of elasticity; moments; nuclear
and outside the containment system.
power plants; nuclear reactor containments; nuclear reactors;
This Code may be referenced and applied subject to agreement
nuclear reactor safety; pipe columns; pipes (tubes); placing; precast
between the Owner and the Regulatory Authority.
concrete; prestressed concrete; prestressing steels; quality control;
The format of this Code is based on the “Building Code Requirement reinforced concrete; reinforcing steels; roofs; safety; serviceability;
for Structural Concrete (ACI 318-95)” and incorporates recent revi-
shear strength; shearwalls; shells (structural forms); spans; specifi-
sions of that standard, except for Chapter 12, which is based on ACI
cations; splicing; strength; strength analysis; structural analysis;
318-99.
structural design; T-beams; temperature; torsion; walls; water;
Keywords: admixtures; aggregates; anchorage (structural); beam-col- welded wire fabric.
umn frame; beams (supports); building codes; cements; cold weather
construction; columns (supports); combined stress; composite con- ACI 349-01 supersedes ACI 349-97 and became effective February 1, 2001.
Copyright (cid:211) 2001, American Concrete Institute.
struction (concrete and steel); composite construction (concrete to All rights reserved including rights of reproduction and use in any form or by any
means, including the making of copies by any photo process, or by electronic or
concrete); compressive strength; concrete construction; concretes;
mechanical device, printed, written, or oral, or recording for sound or visual reproduc-
concrete slabs; construction joints; continuity (structural); cover; tion or for use in any knowledge or retrieval system or device, unless permission in
writing is obtained from the copyright proprietors.
349-1
349-2 ACI STANDARD
CONTENTS
PART 1—GENERAL Chapter 7—Details of Reinforcement. . . . p. 349-19
7.0—Notation
Chapter 1—General Requirements . . . . . . .p. 349-5 7.1—Standard hooks
1.1—Scope
7.2—Minimum bend diameters
1.2—Drawings, specifications, and calculations
7.3—Bending
1.3—Inspection and record keeping
7.4—Surface conditions of reinforcement
1.4—Approval of special systems of design or construction
7.5—Placing reinforcement
1.5—Quality assurance program
7.6—Spacing limits for reinforcement
7.7—Concrete protection for reinforcement
Chapter 2—Definitions . . . . . . . . . . . . . . . . .p. 349-6
7.8—Special reinforcement details for columns
7.9—Connections
PART 2—STANDARDS FOR TESTS AND
7.10—Lateral reinforcement for compression members
MATERIALS
7.11—Lateral reinforcement for flexural members
Chapter 3—Materials. . . . . . . . . . . . . . . . . . .p. 349-9 7.12—Minimum reinforcement
3.0—Notation 7.13—Requirements for structural integrity
3.1—Tests of materials
3.2—Cements
PART 4—GENERAL REQUIREMENTS
3.3—Aggregates
3.4—Water
Chapter 8—Analysis and Design:
3.5—Steel reinforcement General Considerations . . . . . . . . . . . . . p. 349-25
3.6—Admixtures 8.0—Notation
3.7—Storage and identification of materials 8.1—Design methods
3.8—Standards cited in this Code 8.2—Loading
8.3—Methods of analysis
8.4—Redistribution of negative moments in continuous
PART 3—CONSTRUCTION REQUIREMENTS
nonprestressed flexural members
Chapter 4—Durability Requirements. . . . .p. 349-13 8.5—Modulus of elasticity
4.0—Notation 8.6—Stiffness
4.1—Water-cementitious materials ratio 8.7—Span length
4.2—Freezing and thawing exposures 8.8—Columns
4.3—Sulfate exposures 8.9—Arrangement of live load
4.4—Corrosion protection of reinforcement 8.10—T-beam construction
8.11—Joist construction
Chapter 5—Concrete Quality, Mixing,
8.12—Separate floor finish
and Placing. . . . . . . . . . . . . . . . . . . . . . . .p. 349-14
5.0—Notation
Chapter 9—Strength and Serviceability
5.1—General
Requirements . . . . . . . . . . . . . . . . . . . . . p. 349-27
5.2—Selection of concrete proportions
9.0—Notation
5.3—Proportioning on the basis of field experience and/or
9.1—General
trial mixtures
9.2—Required strength
5.4—Proportioning by water-cementitious materials ratio
9.3—Design strength
5.5—Average strength reduction
9.4—Design strength for reinforcement
5.6—Evaluation and acceptance of concrete
9.5—Control of deflections
5.7—Preparation of equipment and place of deposit
5.8—Mixing
Chapter 10—Flexure and Axial Loads . . . p. 349-31
5.9—Conveying
10.0—Notation
5.10—Depositing
10.1—Scope
5.11—Curing
10.2—Design assumptions
5.12—Cold weather requirements
10.3—General principles and requirements
5.13—Hot weather requirements
10.4—Distance between lateral supports of
flexural members
Chapter 6—Formwork, Embedded Pipes,
and Construction Joints . . . . . . . . . . . . .p. 349-18 10.5—Minimum reinforcement of flexural members
6.1—Design of formwork 10.6—Distribution of flexural reinforcement in beams and
6.2—Removal of forms and shores one-way slabs
6.3—Conduits, pipes, and sleeves embedded in concrete 10.7—Deep flexural members
6.4—Construction joints 10.8—Design dimensions for compression members
NUCLEAR SAFETY STRUCTURES CODE 349-3
10.9—Limits for reinforcement of compression members 13.2—Definitions
10.10—Slenderness effects in compression members 13.3—Slab reinforcement
10.11—Magnified moments: General 13.4—Opening in slab systems
10.12—Magnified moments: Non-sway frames 13.5—Design procedures
10.13—Magnified moments: Sway frames 13.6—Direct design method
10.14—Axially loaded members supporting slab system 13.7—Equivalent frame method
10.15—Transmission of column loads through floor system
10.16—Composite compression members Chapter 14—Walls. . . . . . . . . . . . . . . . . . . .p. 349-60
10.17—Bearing strength 14.0—Notation
14.1—Scope
Chapter 11—Shear and Torsion . . . . . . . . p. 349-37 14.2—General
11.0—Notation 14.3—Minimum reinforcement
11.1—Shear strength 14.4—Walls designed as compression members
11.2—Lightweight concrete 14.5—Empirical design method
11.3—Shear strength provided by concrete for 14.6—Nonbearing walls
nonprestressed members 14.7—Walls as grade beams
11.4—Shear strength provided by concrete for prestressed
members Chapter 15—Footings. . . . . . . . . . . . . . . . .p. 349-61
11.5—Shear strength provided by shear reinforcement 15.0—Notation
11.6—Design for torsion 15.1—Scope
11.7—Shear-friction 15.2—Loads and reactions
11.8—Special provisions for deep flexural members 15.3—Footings supporting circular or regular polygon
11.9—Special provisions for brackets and corbels shaped columns or pedestals
11.10—Special provisions for walls 15.4—Moment in footings
11.11—Transfer of moments to columns 15.5—Shear in footings
11.12—Special provisions for slabs and footings 15.6—Development of reinforcement in footings
15.7—Minimum footing depth
Chapter 12—Development and Splices 15.8—Transfer of force at base of column, wall, or
of Reinforcement. . . . . . . . . . . . . . . . . . . p. 349-48 reinforced pedestal
12.0—Notation 15.9—Sloped or stepped footings
12.1—Development of reinforcement: General 15.10—Combined footings and mats
12.2—Development of deformed bars and deformed wire
in tension Chapter 16—Precast Concrete. . . . . . . . . .p. 349-62
12.3—Development of deformed bars in compression 16.0—Notation
12.4—Development of bundled bars 16.1—Scope
12.5—Development of standard hooks in tension 16.2—General
12.6—Mechanical anchorage 16.3—Distribution of forces among members
12.7—Development of welded deformed wire fabric 16.4—Member design
in tension 16.5—Structural integrity
12.8—Development of welded plain wire fabric in tension 16.6—Connection and bearing design
12.9—Development of prestressing strand 16.7—Items embedded after concrete placement
12.10—Development of flexural reinforcement: General 16.8—Marking and identification
12.11—Development of positive moment reinforcement 16.9—Handling
12.12—Development of negative moment reinforcement 16.10—Strength evaluation of precast construction
12.13—Development of web reinforcement
Chapter 17—Composite Concrete
12.14—Splices of reinforcement: General
Flexural Members. . . . . . . . . . . . . . . . . . .p. 349-64
12.15—Splices of deformed bars and deformed wire
17.0—Notation
in tension
17.1—Scope
12.16—Splices of deformed bars in compression
17.2—General
12.17—Special splice requirements for columns
17.3—Shoring
12.18—Splices of welded deformed wire fabric in tension
17.4—Vertical shear strength
12.19—Splices of welded plain wire fabric in tension
17.5—Horizontal shear strength
17.6—Ties for horizontal shear
PART 5—STRUCTURAL SYSTEMS OR ELEMENTS
Chapter 18—Prestressed Concrete. . . . . .p. 349-65
Chapter 13—Two-Way Slab Systems . . . . p. 349-54 18.0—Notation
13.0—Notation 18.1—Scope
13.1—Scope 18.2—General
349-4 ACI STANDARD
18.3—Design assumptions 21.2—General requirements
18.4—Permissible stresses in concrete: Flexural members 21.3—Flexural members of frames
18.5—Permissible stresses in prestressing tendons 21.4—Frame members subjected to bending and axial load
18.6—Loss of prestress 21.5—Joints of frames
18.7—Flexural strength 21.6—Structural walls, diaphragms, and trusses
18.8—Limits for reinforcement of flexural members 21.7—Frame members not proportioned to resist forces
18.9—Minimum bonded reinforcement induced by earthquake motions
18.10—Statically indeterminate structures
18.11—Compression members: Combined flexure and
axial loads APPENDICES
18.12—Slab systems
APPENDIX A—Thermal Considerations. . p. 349-80
18.13—Tendon anchorage zones
A.1—Scope
18.14—Corrosion protection for unbonded prestressing
A.2—Definitions
tendons
A.3—General design requirements
18.15—Post-tensioning ducts
A.4—Concrete temperatures
18.16—Grout for bonded prestressing tendons
18.17—Protection for prestressing tendons
APPENDIX B—Anchoring to Concrete. . . p. 349-81
18.18—Application and measurement of prestressing
B.0—Notation
force
B.1—Definitions
18.19—Post-tensioning anchorages and couplers
B.2—Scope
B.3—General requirements
Chapter 19—Shells . . . . . . . . . . . . . . . . p. 349-70
B.4—General requirements for strength of structural anchors
19.0—Notation
B.5—Design requirements for tensile loading
19.1—Scope and definitions
B.6—Design requirements for shear loading
19.2—General
B.7—Interaction of tensile and shear forces
19.3—Design strength of materials
B.8—Required edge distances, spacings, and thicknesses to
19.4—Section design and reinforcement requirements
preclude splitting failure
19.5—Construction
B.9—Installation of anchors
B.10—Structural plates, shapes, and specialty inserts
PART 6—SPECIAL CONSIDERATIONS B.11—Shear capacity of embedded plates and shear lugs
B.12—Grouted embedments
Chapter 20—Strength Evaluation
of Existing Structures . . . . . . . . . . . . p. 349-72 APPENDIX C—Special Provisions for Impulsive
20.0—Notation and Impactive Effects. . . . . . . . . . . . . . . p. 349-89
20.1—Strength evaluation: General C.0—Notation
20.2—Analytical investigations: General C.1—Scope
20.3—Load tests: General C.2—Dynamic strength increase
20.4—Load test procedure C.3—Deformation
20.5—Loading criteria C.4—Requirements to assure ductility
20.6—Acceptance criteria C.5—Shear strength
20.7—Safety C.6—Impulsive effects
C.7—Impactive effects
Chapter 21—Special Provisions for C.8—Impactive and impulsive loads
Seismic Design. . . . . . . . . . . . . . . . . . . . .p. 349-73
21.0—Notation APPENDIX D—SI Metric Equivalents
21.1—Definitions of U.S. Customary Units. . . . . . . . . . . . . p. 349-92
About the presentation: To aid the reader in distinguishing changes between the 1997 version of
the ACI 349 Code and this 2001 edition, all new or revised sections are marked by a sidebar to the
left of the column.
NUCLEAR SAFETY STRUCTURES CODE 349-5
PART 1—GENERAL
CHAPTER 1—GENERAL REQUIREMENTS typical details, and specifications shall be retained by the
Owner, or his designee, as a permanent record for the life of
1.1—Scope the structure. As a minimum, these drawings, details, and
This Code provides the minimum requirements for the de- specifications together shall show:
sign and construction of nuclear safety related concrete
(a) Name and date of issue of code and supplement to
structures and structural elements for nuclear power generat-
which the design conforms;
ing stations. Safety related structures and structural elements
(b) Live load and other loads used in the design;
subject to this standard are those concrete structures which
support, house, or protect nuclear safety class systems or (c) Specified compressive strength of concrete at stated
component parts of nuclear safety class systems. ages or stages of construction for which each part of
Specifically excluded from this Code are those structures structure is designed;
covered by “Code for Concrete Reactor Vessels and Con- (d) Specified strength or grade of reinforcement;
tainments,” ASME Boiler and Pressure Vessel Code
(e) Size and location of all structural elements and
SectionIII, Division 2, and pertinent General Requirements
reinforcement;
(ACIStandard 359).
(f) Provision for dimensional changes resulting from creep,
1.1.1 This Code includes design and loading conditions
shrinkage, and temperature;
that are unique to nuclear facilities including shear design
under biaxial tension conditions, consideration of thermal (g) Magnitude and location of prestressing forces;
and seismic effects, and impact and impulsive loads. (h) Anchorage length of reinforcement and location and
1.1.2 This Code shall govern in all matters pertaining to length of lap splices;
design and construction of reinforced-concrete structures, as
(i) Type and location of welded splices and mechanical
defined in 1.1.1, except where the Code is in conflict with the
connections of reinforcement; and
specific provisions of the regulatory or jurisdictional author-
(j) Details and locations of all construction or isolation
ities.
joints.
1.1.3 This Code shall govern in all matters pertaining to
design, construction, and material properties wherever this 1.2.2 Calculations pertinent to the design and the basis of
Code is in conflict with requirements contained in other stan- design (including the results of model analysis, if any) shall be
dards referenced in this Code. retained by the Owner or his or her designee, as a permanent
1.1.4 For special structures, such as arches, tanks, reser- record for the life of the structure. Accompanying these
voirs, bins and silos, blast-resistant structures, and chimneys, calculations shall be a statement of the applicable design and
provisions of this Code shall govern where applicable. analysis methods. When computer programs are used, de-
1.1.5 This Code does not govern design and installation of sign assumptions and identified input and output data may be
portions of concrete piles and drilled piers embedded in retained in lieu of calculations. Model analysis shall be per-
ground. mitted to supplement calculations.
1.1.6 This Code does not govern design and construction
of soil-supported slabs, unless the slab transmits vertical 1.3—Inspection and record keeping
loads from other portions of the structure to the soil. 1.3.1 The Owner is responsible for the inspection of
1.1.7—Concrete on steel form deck concrete construction throughout all work stages. The Owner
shall require compliance with design drawings and
1.1.7.1 Design and construction of structural concrete
specifications. The Owner shall also keep records required for
slabs cast on stay-in-place, noncomposite steel form deck are
quality assurance and traceability of construction, fabrication,
governed by this Code.
material procurement, manufacture, or installation.
1.1.7.2 This Code does not govern the design of struc-
1.3.2 The Owner shall be responsible for designating the
tural concrete slabs cast on stay-in-place, composite steel
records to be maintained and the duration of retention.
form deck. Concrete used in the construction of such slabs
Records pertinent to plant modifications or revisions, in-ser-
shall be governed by Parts 1, 2, and 3 of this Code, where ap-
vice inspections, and durability and performance of struc-
plicable.
tures shall be maintained for the life of the plant. The Owner
1.1.8 Special provisions for earthquake resistance—Provi-
shall be responsible for continued maintenance of the
sions of Chapter 21 shall be satisfied. See 21.2.1.
records. The records shall be maintained at the power plant
site, or at other locations as determined by the Owner. As a
minimum, the following installation/construction records
1.2—Drawings, specifications, and calculations
shall be considered for lifetime retention:
1.2.1 Copies of structural drawings, typical details, and
specifications for all reinforced concrete construction shall (a) Check-off sheets for tendon and reinforcing
be signed by a licensed engineer. These drawings (including steel installation;
supplementary drawings to generate the as-built condition), (b) Concrete cylinder test reports and charts;
349-6 ACI STANDARD
(c) Concrete design mix reports; Cementitious materials—Materials as specified in Chapter
(d) Concrete placement records; 3 that have cementing value when used in concrete either by
themselves, such as portland cement, blended hydraulic ce-
(e) Sequence of erection and connection of precast mem-
ments, and expansive cement, or such materials in combina-
bers;
tion with fly ash, other raw or calcined natural pozzolans,
(f) Reports for construction and removal of forms and
silica fume, and/or ground-granulated blast-furnace slag.
reshoring;
(g) Material property reports on reinforcing steel; Column—Member with a ratio of height-to-least-lateral di-
(h) Material property reports on reinforcing steel mension of 3 or greater used primarily to support axial com-
mechanical connection material; pressive load.
(i) Material property reports on steel embedments
Composite concrete flexural members—Concrete flexural
in concrete;
members of precast and/or cast-in-place concrete elements
(j) Material property reports on tendon and anchorage constructed in separate placements but so interconnected
fabrication material and corrosion inhibitors; that all elements respond to loads as a unit.
(k) Reports for periodic tendon inspection;
Compression-controlled section—A cross section in which
(l) Tensioning of prestressing tendons; and
the net tensile strain in the extreme tension steel at nominal
(m)Quality and proportions of concrete materials.
strength is less than or equal to the compression-controlled
strain limit.
1.4—Approval of special systems of design or
construction Compression-controlled strain limit—The net tensile strain
Sponsors of any system of design or construction within at balanced-strain conditions.
the scope of this Code, the adequacy of which has been
Concrete—Mixture of portland cement or any other hydrau-
shown by successful use or by analysis or test, but which
lic cement, fine aggregate, coarse aggregate, and water, with
does not conform to or is not covered by this Code, shall
or without admixtures.
have the right to present the data on which their design is
based to the Regulatory Authority for review and approval. Concrete, specified compressive strength of, (f¢¢ )—Com-
c
The Regulatory Authority may investigate the data so sub-
pressive strength of concrete used in design and evaluated in
mitted, and may require tests and formulate rules governing
accordance with provisions of Chapter 5, expressed in
the design and construction of such systems to meet the in- pounds per square inch (psi). Whenever the quantity f¢ is un-
c
tent of this Code.
der a radical sign, square root of numerical value only is in-
tended, and the result has units of psi.
1.5—Quality assurance program
A quality assurance program covering nuclear safety re- Contraction joint—Formed, sawed, or tooled groove in a
lated structures shall be developed prior to starting any work. concrete structure used to create a weakened plane and reg-
The general requirements and guidelines for establishing and ulate the location of cracking resulting from the dimensional
executing the quality assurance program during the design change of different parts of the structure.
and construction phases of nuclear power generating stations
Creep—Stress-induced, time-temperature dependent strain.
are established by Title 10 of the Code of Federal Regula-
tions, Part 50 (10CFR50), Appendix B. Curvature friction—Friction resulting from bends or curves
in the specified prestressing tendon profile.
CHAPTER 2—DEFINITIONS
Deformed reinforcement—Deformed reinforcing bars, bar
2.1 The following terms are defined for general use in this
and rod mats, deformed wire, welded smooth wire fabric, and
Code. Specialized definitions appear in individual chapters.
welded deformed wire fabric conforming to 3.5.3.
Admixture—Material other than water, aggregate, or hy- Development length—Length of embedded reinforcement
draulic cement, used as an ingredient of concrete and add- required to develop the design strength of reinforcement at a
ed to concrete before or during its mixing to modify its critical section. See 9.3.3.
properties.
Effective depth of section (d)—Distance measured from ex-
Aggregate—Granular material, such as sand, gravel, treme compression fiber to centroid of tension reinforcement.
crushed stone, and iron blast-furnace slag, used with a ce-
menting medium to form a hydraulic-cement concrete or Effective prestress—Stress remaining in prestressing ten-
mortar. dons after all losses have occurred excluding effects of dead
load and superimposed load.
Anchorage—In post-tensioning, a device used to anchor
Embedment—A steel component embedded in the concrete
tendon to concrete member; in pretensioning, a device used
to transmit applied loads to the concrete structure. The em-
to anchor tendon during hardening of concrete.
bedment can be fabricated of plates, shapes, fasteners, rein-
Bonded tendon—Prestressing tendon that is bonded to con- forcing bars, shear connectors, inserts, or any combination
crete either directly or through grouting. thereof.
NUCLEAR SAFETY STRUCTURES CODE 349-7
Embedment length—Length of embedded reinforcement tional. The OBE is only associated with plant shutdown and
provided beyond a critical section. inspection unless selected by the Owner as a design input.
See Appendix S of 10CFR50 of the Federal Regulation.
Engineer—The licensed professional engineer, employed
by the Owner-contracted design authority or other agency, Operating basis wind—Wind velocities and forces required
responsible for issuing design drawings, specifications, or
for the design of a structure in accordance with ASCE 7-95
other documents.
for a 100 year recurrence interval.
Evaluation—An engineering review of an existing safety
Owner—The organization responsible for the operation,
related concrete structure with the purpose of determining
maintenance, safety, and power generation of the nuclear
physical condition and functionality. This review may in-
power plant.
clude analysis, condition surveys, maintenance, testing, and
repair.
Pedestal—Upright compression member with a ratio of un-
supported height to average least lateral dimension of less
Extreme tension steel—The reinforcement, prestressed or
nonprestressed, that is the farthest from the extreme com- than 3.
pression fiber.
Plain concrete—Structural concrete with no reinforcement
Isolation joint—A separation between adjoining parts of a or with less reinforcement than the minimum amount speci-
concrete structure, usually a vertical plane at a designed loca- fied for reinforced concrete.
tion so as to interfere least with the performance of the struc-
Plain reinforcement—Reinforcement that does not conform
ture, yet allow relative movement in three directions and
avoid formation of cracks elsewhere in the concrete and to definition of deformed reinforcement. See 3.5.4.
through which all or part of the bonded reinforcement is
Post-tensioning—Method of prestressing in which tendons
interrupted.
are tensioned after concrete has hardened.
Jacking force—In prestressed concrete, temporary force
Precast concrete—Structural concrete element cast else-
exerted by device that introduces tension into prestressing
tendons. where than its final position in the structure.
Load, dead—Dead weight supported by a member (without Prestressed concrete—Structural concrete in which internal
load factors). stresses have been introduced to reduce potential tensile
stresses in concrete resulting from loads.
Load, factored—Load, multiplied by appropriate load fac-
tors, used to proportion members by the strength design Pretensioning—Method of prestressing in which tendons
method of this code. See 8.1 and 9.2. are tensioned before concrete is placed.
Load, live—Live load specified by the engineer (without
Regulatory Authority—The governmental agency or agen-
load factors).
cies having legal jurisdiction over the design, construction,
Load, sustained—Dead load and the portions of other nor- and operation of nuclear power generating stations to assure
mal loads in 9.1.1 which are expected to act for a sufficient public health and safety.
period of time to cause time-dependent effects.
Reinforced concrete—Concrete containing adequate rein-
Massive concrete—Mass of concrete of sufficient dimen- forcement, prestressed or nonprestressed, and designed on
sions to produce excessive temperatures due to heat of hy- the assumption that the two materials act together in resisting
dration unless special precautions are taken regarding forces.
concrete placement temperatures, placing rate, or heat re-
moval. Portions of the structure to be treated as massive con- Reinforcement—Material that conforms to 3.5, excluding
crete shall be so identified on the design drawings or prestressing tendons unless specifically included.
specifications.
Reshores—Shores placed snugly under a concrete slab or
Modulus of elasticity—Ratio of normal stress to corre- other structural member after the original forms and shores
sponding strain for tensile or compressive stresses below have been removed from a larger area, thus requiring the new
proportional limit of material. See 8.5. slab or structural member to deflect and support its own
weight and existing construction loads applied prior to the
Net tensile strain—The tensile strain at nominal strength ex-
installation of the reshores.
clusive of strains due to effective prestress, creep, shrinkage,
and temperature.
Safe shutdown earthquake—The safe shutdown earthquake
Operating basis earthquake—The operating basis earthquake ground motion (SSE) is the vibratory ground motion for
(OBE) for a reactor site is that which produces the vibratory which certain structures, systems, and components (SSCs) in
ground motion for which those features of the nuclear plant nuclear power plants must be designed to remain functional.
necessary for continued operation without undue risk to the For the definition of these SSCs, see Appendix S of
health and safety of the public are designed to remain func- 10CFR50 of the Federal Regulation.
349-8 ACI STANDARD
Shores—Vertical or inclined support members designed to Stress relaxation—A phenomenon in which loss of stress
carry the weight of the formwork, concrete, and construction occurs when a constant strain is maintained at a constant
loads above. temperature.
Shrinkage—Time-temperature-humidity dependent volume Tendon—Steel element such as wire, cable, bar, rod, or
reduction of concrete as a result of hydration, moisture mi- strand, or a bundle of such elements, used to impart prestress
gration, and drying process. to concrete.
Span length—See 8.7. Tension-controlled section—A cross section in which the
net tensile strain in the extreme tension steel at nominal
Spiral reinforcement—Continuously wound reinforcement
strength is greater than or equal to 0.005.
in the form of a cylindrical helix.
Tie—Loop of reinforcing bar or wire enclosing longitudinal
Stirrup—Reinforcement used to resist shear and torsion
reinforcement. A continuously wound bar or wire in the form
stresses in a structural member; typically bars, wires, or
of a circle, rectangle, or other polygon shape without reentrant
welded wire fabric (plain or deformed) bent into L, U, or
corners is acceptable. See also stirrup.
rectangular shapes and located perpendicular to or at an an-
gle to longitudinal reinforcement. (The term “stirrups” is Transfer—Act of transferring stress in prestressing tendons
usually applied to lateral reinforcement in flexural members from jacks or pretensioning bed to concrete member.
and the term “ties” to those in compression members.) See
Unbonded tendons—Tendons in which the prestressing
also Tie.
steel is permanently free to move relative to the surrounding
Strength, design—Nominal strength multiplied by a concrete to which they are applying their prestressing forces.
strength reduction factor ff . See 9.3.
Wall—Member, usually vertical, used to enclose or separate
Strength, nominal—Strength of a member or cross section spaces.
calculated in accordance with provisions and assumptions of
Wobble friction—In prestressed concrete, friction caused by
the strength design method of this code before application of
unintended deviation of prestressing sheath or duct from its
any strength reduction factors. See 9.3.1.
specified profile.
Strength, required—Strength of a member or cross section
Yield strength—Specified minimum yield strength or yield
required to resist factored loads or related internal moments
point of reinforcement in pounds per square inch. Yield
and forces in such combinations as are stipulated in this
strength or yield point is determined in tension according to
code. See 9.1.1.
applicable ASTM specifications as modified by 3.5 of this
Stress—Intensity of force per unit area. Code.
NUCLEAR SAFETY STRUCTURES CODE 349-9
PART 2—STANDARDS FOR TESTS AND MATERIALS
CHAPTER 3—MATERIALS These limitations may be waived if, in the judgment of the
engineer, workability, and methods of consolidation are such
3.0—Notation that concrete can be placed without honeycomb or voids.
f = specified yield strength of nonprestressed
y
reinforcement, psi 3.3.3—Testing requirements
3.3.3.1 Tests for full conformance with the appropriate
3.1—Tests of materials specification, including tests for potential reactivity, shall
3.1.1 The Owner shall have the right to order testing of any be performed prior to usage in construction unless such
materials used in concrete construction to determine if mate- tests are specifically exempted by the specifications as not
rials are of quality specified. being applicable.
3.1.2 Tests of materials and of concrete shall be made in 3.3.3.2 A daily inspection control program shall be
accordance with standards listed in 3.8. carried out during concrete production to determine and
3.1.3 A complete record of tests of materials and of con- control consistency in potentially variable characteristics
crete shall be available for inspection as required by1.3.2. such as water content, gradation, and material finer than
No. 200 sieve.
3.3.3.3 Tests for conformance with ASTM C131,
3.2—Cements
3.2.1 Cement shall conform to one of the following speci- ASTM C 289, and ASTM C 88 shall be repeated whenever
fications for portland cement: there is reason to suspect a change in the basic geology or
mineralogy of the aggregates.
(a) “Specification for Portland Cement” (ASTM C 150); or
(b) “Specification for Blended Hydraulic Cements”
3.4—Water
(ASTMC 595), excluding Types S and SA which are
3.4.1 Water used in mixing concrete shall be clean and
not intended as principal cementing constituents of
free from injurious amounts of oils, acids, alkalis, salts, or-
structural concrete; or
ganic materials, or other substances that may be deleterious
(c) “Specification for Expansive Hydraulic Cement” to concrete or reinforcement.
(ASTM C 845). 3.4.2 Mixing water for prestressed concrete or for con-
3.2.2 Cement used in the work shall correspond to that on crete that will contain aluminum embedments, including
which selection of concrete proportions was based. See 5.2. that portion of mixing water contributed in the form of free
3.2.3 Every shipment of cement shall be accompanied by moisture on aggregates, shall not contain deleterious
a certified mill test report stating the results of tests repre- amounts of chloride ion. See 4.3.1.
senting the cement in shipment and the ASTM specifica- 3.4.3 Nonpotable water shall not be used in concrete un-
tion limits for each item of required chemical, physical, and less the following are satisfied:
optional characteristics. No cement shall be used in any (a) Selection of concrete proportions shall be based on con-
structural concrete prior to receipt of 7 day mill test crete mixes using water from the same source.
strengths.
(b) Mortar test cubes made with nonpotable mixing water
shall have 7-day and 28-day strengths equal to at least
3.3—Aggregates 90% of strengths of similar specimens made with pota-
3.3.1 Concrete aggregates shall conform to one of the fol- ble water. Strength test comparison shall be made on mor-
lowing specifications: tars, identical except for the mixing water, prepared and
(a) “Specification for Concrete Aggregates” (ASTM C 33); or tested in accordance with “Method of Test for Compres-
(b) “Specification for Aggregates for Radiation-Shielding sive Strength of Hydraulic Cement Mortars (Using 2-inch
Concrete” (ASTM C 637). or 50-mm Cube Specimens)” (ASTMC109).
Exception: Aggregates failing to meet ASTM C 33 but
3.5—Steel reinforcement
which have been shown by special test or actual service to
3.5.1 Reinforcement shall be deformed reinforcement, ex-
produce concrete of adequate strength and durability shall be
cept that plain reinforcement may be used for spirals or ten-
permitted to be used for normal-weight concrete where au-
dons; and reinforcement consisting of structural steel, steel
thorized by the engineer.
pipe, or steel tubing shall be permitted as specified in this
3.3.2 Nominal maximum size of coarse aggregate shall not
code.
be larger than:
3.5.2 Welding of reinforcing bars shall conform to “Struc-
(a) 1/5 the narrowest dimension between sides of forms, nor tural Welding Code—Reinforcing Steel,” ANSI/AWS D1.4
(b) 1/3 the depth of slabs, nor of the American Welding Society. Type and location of
(c) 3/4 the minimum clear spacing between individual rein- welded splices and other required welding of reinforcing
forcing bars or wires, bundles of bars, or prestressing bars shall be indicated on the design drawings or in the
tendons or ducts. project specifications. ASTM reinforcing bar specifications,
349-10 ACI STANDARD
except for ASTM A 706, shall be supplemented to require a (ASTMA421).
report of material properties necessary to conform to the (b) Low-relaxation wire conforming to “Specification for
requirements in ANSI/AWS D1.4. Uncoated Stress-Relieved Steel Wire for Prestressed
3.5.3—Deformed reinforcement Concrete” including Supplement “Low-Relaxation
3.5.3.1 Deformed reinforcing bars shall conform to Wire” (ASTM A 421).
one of the following specifications: (c) Strand conforming to “Specification for Uncoated
(a) “Specification for Deformed and Plain Billet-Steel Seven-Wire Stress-Relieved Strand for Prestressed
Bars for Concrete Reinforcement” (ASTM A615). Concrete” (ASTM A 416).
(b) “Specification for Low-Alloy Steel Deformed Bars for (d) Bars conforming to “Specification for Uncoated High-
Concrete Reinforcement” (ASTM A706). Strength Steel Bar for Prestressing Concrete”
3.5.3.1.1 A minimum of one tensile test shall be re- (ASTMA722).
quired for each 50 tons of each bar size produced from 3.5.5.2 Wire, strands, and bars not specifically listed
each heat of steel. in ASTM A 421, A 416, or A 722 are permitted provided
3.5.3.2 Specified yield strength f for deformed rein- they conform to minimum requirements of these specifica-
y
forcing bars shall not exceed 60,000 psi. tions and do not have properties that make them less satis-
3.5.3.3 Bar mats for concrete reinforcement shall con- factory than those listed in ASTM A 421, A 416, or A 722.
form to “Specification for Fabricated Deformed Steel Bar 3.5.6—Structural steel, steel pipe, or tubing
Mats for Concrete Reinforcement” (ASTM A184). Rein- 3.5.6.1 Structural steel used with reinforcing bars in
forcement used in bar mats shall conform to one of the composite compression members meeting requirements of
specifications listed in 3.5.3.1. 10.14.7 or 10.14.8 shall conform to one of the following
3.5.3.4 Deformed wire for concrete reinforcement specifications:
shall conform to “Specification for Deformed Steel Wire
(a) “Specification for Structural Steel” (ASTM A 36).
for Concrete Reinforcement” (ASTM A496), except that
(b) “Specification for High-Strength Low-Alloy Struc-
wire shall not be smaller than size D4.
tural Steel” (ASTM A 242).
3.5.3.5 Welded plain wire fabric for concrete rein-
(c) “Specification for High-Strength Low-Alloy Colum-
forcement shall conform to “Specification for Welded
bium-Vanadium Steels of Structural Quality”
Steel Wire Fabric for Concrete Reinforcement” (ASTM
(ASTMA572).
A185). Welded intersections shall not be spaced farther
(d) “Specification for High-Strength Low-Alloy
apart than 12 in. in direction of calculated stress, except for
Structural Steel with 50 ksi Minimum Yield Point to 4
wire fabric used as stirrups in accordance with 12.13.2.
in. Thick” (ASTM A 588).
3.5.3.6 Welded deformed wire fabric for concrete re-
inforcement shall conform to “Specification for Welded 3.5.6.2 Steel pipe or tubing for composite compres-
Deformed Steel Wire Fabric for Concrete Reinforcement” sion members composed of a steel encased concrete core
(ASTM A497). Welded intersections shall not be spaced meeting requirements of 10.14.6 shall conform to one of
farther apart than 16 in. in direction of calculated stress, the following specifications:
except for wire fabric used as stirrups in accordance with (a) Grade B of “Specification for Pipe, Steel, Black and
12.13.2. Hot-Dipped, Zinc-Coated, Welded and Seamless”
3.5.3.7 (This section not used to maintain section (ASTM A53).
number correspondence with ACI 318-95). (b) “Specification for Cold-Formed Welded and Seamless
3.5.3.8 Epoxy-coated reinforcing bars shall comply Carbon Steel Structural Tubing in Rounds and
with “Specification for Epoxy Coated Reinforcing Steel Shapes” (ASTM A500).
Bars” (ASTM A 775) or with “Specification for Epoxy-
(c) “Specification for Hot-Formed Welded and Seamless
Coated Prefabricated Steel Reinforcing Bars” (ASTM A
Carbon Steel Structural Tubing” (ASTM A501).
934). The engineer shall evaluate the suitability of coated
reinforcing steel for the expected service environment in 3.6—Admixtures
each application. Epoxy-coated reinforcing steel shall also 3.6.1 Admixtures to be used in concrete shall be subject
conform to one of the specifications listed in 3.5.3.1. to prior approval by the engineer.
3.5.4—Plain reinforcement 3.6.2 An admixture shall be shown capable of maintain-
3.5.4.1 Plain bars for spiral reinforcement shall con- ing essentially the same composition and performance
form to the specification listed in 3.5.3.1(a) including ad- throughout the work as the product used in establishing
ditional requirements of 3.5.3.1.1. concrete proportions in accordance with 5.2.
3.5.4.2 Smooth wire for spiral reinforcement shall 3.6.3 Calcium chloride or admixtures containing chlo-
conform to “Specification for Cold-Drawn Steel Wire for ride from other than impurities from admixture ingredients
Concrete Reinforcement” (ASTM A82). shall not be used in prestressed concrete, in concrete con-
3.5.5—Prestressing tendons taining embedded aluminum, or in concrete cast against
3.5.5.1 Tendons for prestressed reinforcement shall stay-in-place galvanized metal forms. See 4.3.2 and 4.4.1.
conform to one of the following specifications: 3.6.4 Air-entraining admixtures shall conform to “Spec-
(a) Wire conforming to “Specification for Uncoated ification for Air-Entraining Admixtures for Concrete”
Stress-Relieved Wire for Prestressed Concrete” (ASTMC260).