Deletion legend:
[1- Default – Not related
to structural wind resistance design]
[2- Fire/Life Safety]
[3- Covered in model base
code]
SECTION 1919
HIGH-VELOCITY HURRICANE ZONES—GENERAL
1919.1 Scope. This section prescribes requirements for
reinforced concrete in construction regulated by this code.
1919.2 Application. Reinforced concrete shall be of the
materials, proportions strength and consistency as set forth in this section
and shall be designed by methods admitting of rational analysis according to
established principles of mechanics.
1919.3 Requirements. All structures of reinforced
concrete, including prestressed concrete, shall be designed and constructed in
accordance with the provisions of ACI 318 as adopted herein.
1919.4 Workmanship. Concrete construction shall be in
conformance with the tolerance, quality and methods of construction set forth
in Section 1920.
[3- Covered
in model base code]1903
SECTION 1920
HIGH-VELOCITY HURRICANE ZONES —
STANDARDS
1920.1 The following standards are hereby adopted as part
of this code as set forth in Chapter 35 of this code.
1920.2 American Concrete Institute (ACI).
1. Standard
Tolerances for Concrete Construction and Materials, ACI 117.
2. Specifications
for Structural Concrete for Buildings, ACI 301.
3. Manual
of Standard Practice for Detailing Reinforced Concrete Structures, ACI 315.
4. Building
Code Requirements for Reinforced Concrete, ACI 318.
5. Recommended
Practice for Concrete Formwork, ACI 347.
6. Recommended
Practice for Shotcreting, ACI 506.
7. Specification
for Materials, Proportioning, and Application of Shotcrete, ACI 506.2.
8. Deformed
and Plain Billet Steel Bars for Concrete Reinforcement, ASTM A615, including
S1.
1920.3 American National Standards Institute (ANSI)/American
Society of Civil Engineers (ASCE).
1. Specifications
for the Design and Construction of Composite Slabs and Commentary on
Specifications for the Design and Construction of Composite Slabs, ANSI/ASCE 3.
2. Guideline
for Structural Assessment of Existing Buildings, ANSI/ASCE 11.
1920.4 American Society for Testing Materials (ASTM).
1. Deformed
and Plain Billet Steel Bars for Concrete Reinforcement, ASTM A 615, including
S1.
2. Testing
Concrete Aggregates for Use in Construction and Criteria for Laboratory
Evaluation, ASTM C 1077.
[3- Covered in model base
code]1903
SECTION 1921
HIGH-VELOCITY HURRICANE ZONES—
DEFINITIONS
1921.1 The following definitions apply to the provisions
of Sections 1919 through 1929.
PLAIN CONCRETE. Concrete that is either unreinforced or
contains less reinforcement than the minimum amount specified for reinforced
concrete.
REINFORCED CONCRETE. Concrete reinforced with no less
than the minimum amount required by ACI 318, prestressed or non-prestressed,
and designed on the assumption that the two materials act together in resisting
forces.
PRESTRESSED CONCRETE. Reinforced concrete in which
internal stresses have been introduced to reduce potential tensile stresses in
concrete resulting from loads, The term prestressed concrete refers to
pretensioned concrete in which the reinforcing is tensioned before hardening of
the concrete, to postensioned concrete in which the reinforcing is tensioned
after hardening of the concrete, or combinations of both pretensioning and
posttensioning.
PRECAST CONCRETE. Plain or reinforced concrete elements
cast elsewhere than their final position in a structure.
SHOTCRETE. Mortar or concrete pneumatically projected at
high velocity onto a surface.
[3- Covered
in model base code]1903
SECTION 1922
HIGH-VELOCITY HURRICANE ZONES—
MATERIALS
1922.1 Cements. Cements shall conform to one of the
following specifications for portland cement as set forth in Chapter 35.
1. Portland
Cement, ASTM C 150.
2. Blended
Hydraulic Cements, ASTM C 595, excluding Types S and SA, which are not intended
as principal cementing constituents of structural concrete.
[3- Covered in model base code]1903
1922.2 Aggregates for concrete shall conform to one of
the following specifications as set forth in Chapter 35 of this code or Section
1922.2.1.
1. Concrete
Aggregates, ASTM C 33.
2. Lightweight
Aggregates for Structural Concrete, ASTM C 330.
1922.2.1 Gradation of locally produced sand and crushed
rock aggregate shall be as follows:
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1922.2.2 Aggregates failing to meet ASTM C 33, ASTM C 330
or the above special gradation but which have been shown by special test or
actual service to produce concrete of adequate strength and durability may be
used when certified by the engineer.
1922.2.3 Aggregates shall be quarried or washed in fresh
water and shall contain not more than 1/20 of 1-percent salt by weight.
[3- Covered in model base code]1903
1922.3 Water used in mixing concrete shall be clean and
free from injurious amounts of oils, acids, alkalis, salts, organic materials
or other substances that may be deleterious to concrete or reinforcement.
1922.3.1 Mixing water for concrete, including that
portion of mixing water contributed in the form of free moisture on aggregates,
shall not contain deleterious amounts of chloride ion.
[3- Covered in model base code]1903
1922.4 Reinforcement.
1922.4.1 Deformed reinforcement shall conform to one of
the specifications as set forth in Chapter 35, except as provided in Section
3.5 of ACI 318.
1922.4.2 Prestressing tendons shall conform to one of the
specifications as set forth in Chapter 35.
Exception: Wire strands and bars not specifically listed
in ASTM A 421, A 416, or A 722 may be used provided they conform to minimum
requirements of these specifications and do not have properties that make them
less satisfactory than those listed in ASTM A 416, A 421 or A 722.
1922.4.3 Reinforcement consisting of structural steel,
steel pipe or steel tubing may be used as specified in ACI 318.
1922.4.4 All welding of reinforcement shall conform to
the Structural Welding Code - Reinforcing Steel, AWS D1.4, as set forth in
Chapter 35.
1922.4.5 Reinforcement to be welded shall be indicated on
the drawings, and welding procedures to be used shall be specified. ASTM steel
specifications, except ASTM A 706, shall be supplemented to require a report of
material properties necessary to conform to welding procedures specified in AWS
D1.4.
1922.4.6 Deformed reinforcement may be galvanized or
epoxy-coated in accordance with the Specifications for Zinc-Coated (galvanized)
Bars for Concrete reinforcement, ASTM A 767 or the Specification for
Epoxy-Coated Bars, ASTM A 775. Zinc or epoxy-coated reinforcement shall conform
to ASTM A 615, A 616 (S1), A 617 or A 706.
[3- Covered in model base code]1903
1922.5 Admixtures.
1922.5.1 Admixtures to be used in concrete shall conform
to one of the specifications set forth in Chapter 35.
1922.5.2 An admixture shall be shown capable of
maintaining essentially the same composition and performance throughout the
work as the product used in establishing concrete proportions.
1922.5.3 Admixtures containing chloride ions shall not be
used in concrete if their use will produce a deleterious concentration of
chloride ion in the mixing water.
[3- Covered in model base code]1903
1922.6 Test of materials.
1922.6.1 The building official, or his or her authorized
representative, shall have the right to order the test of any material entering
into concrete or reinforced concrete to determine its suitability for the
purpose; to order reasonable tests of the concrete from time to time to
determine whether the materials and methods in use are such as to produce
concrete of the necessary quality; and to order the test under load of any
portion of a completed structure when conditions have been such as to leave
doubt as to the adequacy of the structure to serve the purpose for which it is
intended.
1922.6.2 Materials shall be tested and of concrete shall be
tested in accordance with applicable standards of ASTM International as listed
in Chapter 35. Tests shall be made by an approved testing laboratory and
results of such tests shall be submitted to the building official. Approved
testing laboratories shall comply with ASTM C 1077.
1922.6.3 A complete record of tests of materials and of
concrete shall be available to the building official for inspection during
progress of work and for five years after completion of the project, and shall
be preserved by the inspecting engineer or architect for that purpose.
1922.6.4 If doubt develops concerning the safety of a
structure or member, the building official may order a structural strength investigation
by analysis or by means of load tests, or by a combination of analyses and load
test as set forth in Chapter 20 of ACI 318.
[3- Covered
in model base code]1903
SECTION 1923
HIGH-VELOCITY HURRICANE ZONES— CONCRETE QUALITY
1923.1 General.
1923.1.1 Concrete shall be proportioned and produced to
provide an average compressive strength sufficiently high to minimize the
frequency of strength test below the specified compressive strength of
concrete, f ˘c .
1923.1.2 Requirements for f ˘c shall be based on tests of
cylinders made and tested as prescribed in Section 1923.2.2.3.
1923.1.3 Unless otherwise specified, f ˘c shall be based
on 28-day tests. If other than 28-day tests are called for, f ˘c shall be
indicated in design drawings or specifications.
1923.1.4 Design drawings shall show the specified
compressive strength of concrete, f ˘c for which each part of the structure is
designed.
[3- Covered in model base code]1903
1923.2 Evaluation and acceptance concrete.
1923.2.1 Frequency of testing.
1923.2.1.1 The building official may require a reasonable
number of tests to be made during the progress of the work, or may promulgate
and set forth in writing such reasonable rules for requiring tests to be made
by an approved laboratory as he may consider necessary to insure compliance
with this code.
1923.2.1.2 Not less than three specimens shall be made
for each standard test.
1923.2.1.3 Samples for strength of each class of concrete
placed each day shall be taken not less than once a day, nor less than once for
each 150 cubic yard (4.3 m3) of concrete, nor less than once for each 5,000
square feet (465 m2) of surface area for slabs or walls.
1923.2.1.4 On a given project, if total volume of
concrete is such that frequency of testing required by Section 1923.2.1.1 would
provide less than five strength tests for a given class of concrete, tests
shall be made from at least five randomly selected batches or from each batch
if fewer than five batches are used.
1923.2.1.5 Test cylinders taken on truck-mixed concrete
shall be taken at the approximate one-quarter point of the load.
1923.2.1.6 The age for strength tests shall be 28 days,
or where specified, at the earlier age at which the concrete is to receive its
full working load.
[3- Covered in model base code]1903
1923.2.2 Laboratory cured specimens.
1923.2.2.1 A strength test shall be the average of the
strengths of two cylinders made from the same sample of concrete and tested at
28 days or at a test age designated for determination of f ˘c .
1923.2.2.2 Samples of strength tests shall be taken in
accordance with the Method of Sampling Fresh Concrete, ASTM C 172, as set forth
in Chapter 35.
1923.2.2.3 Cylinders for strength tests shall be molded
and laboratory-cured in accordance with the Method of Making and Curing
Concrete Test Specimens in the Field, ASTM C 31, as set forth in Chapter 35 of
this code, and tested in accordance with the Method of Test for Compressive
Strength of Cylindrical Concrete Specimens, ASTM C 39, as set forth in Chapter
35.
1923.2.2.4 The strength level of an individual class of
concrete shall be considered satisfactory if both of the following requirements
are met:
1. Average
of all sets of three consecutive strength tests equal or exceed f ˘c .
2. No
individual strength test (average of 2 cylinders) falls below f ˘c by more than
500 psi (3448 kPa).
1923.2.2.5 If any of the requirements of Section 1923.2
are not met, steps shall be taken to increase the average of subsequent
strength test results. Requirements of Section 1923.2.4 shall be observed if
any individual strength test falls below f ˘c by more than 500 psi (3448 kPa).
[3- Covered in model base code]1903
1923.2.3 Field cured specimens.
1923.2.3.1 The building official may require strength
tests of cylinders cured under field conditions to check adequacy of curing and
protection of concrete in the structure.
1923.2.3.2 Field-cured cylinders shall be cured under
field conditions in accordance with Section 7.4 of the Method of Making and
Curing Concrete Test specimens in the Field, ASTM C 31.
1923.2.3.3 Field-cured test cylinders shall be molded at
the same time and from the same samples as laboratory-cured test cylinders.
1923.2.3.4 Procedures for protecting and curing concrete
shall be improved when the strength of field-cured cylinders at test age
designated for determination of f ˘c is less than 85 percent of that of
companion laboratory cured cylinders. The 85 percent may be waived if field
cured strength exceeds f ˘c by more than 500 psi (3448 Pa).
[3- Covered in model base code]1903
1923.2.4 Investigation of low strength test results.
1923.2.4.1 When there is a question as to the quality of
the concrete in the structure, the building official may require core tests in
accordance with the Standard Method of Obtaining and Testing Drilled Cores and
Sawed Beams of Concrete, ASTM C 42, as set forth in Chapter 35 of this code, or
order load tests on that portion of the structure where the questionable
concrete has been placed.
1923.2.4.2 When concrete in structures has failed to meet
the minimum standard, the building official shall order analysis and reports by
a registered engineer to determine the adequacy of the structure.
1923.2.4.3 If the likelihood of low-strength concrete is
confirmed and computations indicate that load-carrying capacity may have been
significantly reduced, tests of cores drilled from the area in question may be
required in accordance with the Method of Obtaining and Testing Drilled Cores
and Sawed Beams of Concrete, ASTM C 42, as set forth in Chapter 35 of this
code. In such case, three cores shall be taken for each strength test more than
500 psi (3448 kPa) below specified value of f ˘c .
1923.2.4.4 If concrete in the structure will be dry under
service conditions, cores shall be air dried at a temperature between 60°F
(15°C) and 80°F (27°) and a relative humidity less than 60 percent for 7 days
before testing and shall be tested dry. If concrete in the structure will be
more than superficially wet under service conditions, cores shall be immersed
in water for at least 40 hours and be tested wet.
1923.2.4.5 Concrete in an area represented by core tests
shall be considered structurally adequate if the average of three cores is
equals to at least 85 percent of f ˘c and if no single core is less than 75
percent of f ˘c . To check testing accuracy, locations represented by erratic
core strengths may be retested.
1923.2.4.6 Slump considerations. The maximum allowable
slump of concrete shall be 6 inches (152 mm). On jobs controlled and supervised
by a professional engineer, this maximum may be exceeded, but no concrete shall
exceed the slump as indicated on the approved plans for proposed work.
[3- Covered
in model base code]1903
SECTION 1924
HIGH-VELOCITY HURRICANE ZONES— MIXING AND PLACING
CONCRETE
1924.1 Preparation of equipment and place of deposit.
1924.1.1 Preparation before concrete placement shall
include the following:
1. All
equipment for mixing and transporting concrete shall be clean.
2. All
debris shall be removed from the spaces to be occupied by the concrete.
3. Forms
shall be properly coated.
4. Masonry
filler units that will be in contact with concrete shall be well drenched.
5. Reinforcement
shall be thoroughly cleaned of deleterious coatings.
6. Water
shall be removed from place of deposit before concrete is placed unless a
tremie is to be used or unless otherwise permitted by the professional
engineer.
7. All
laitance and other unsound material shall be removed before additional concrete
is placed against hardened concrete.
[3- Covered in model base code]1903
1924.2 Mixing.
1924.2.1 All concrete shall be mixed until there is
uniform distribution of materials and shall be discharged completely before the
mixer is recharged.
1924.2.2 Ready-mixed concrete shall be mixed and
delivered in accordance with requirements of the Specifications for Ready-Mixed
Concrete, ASTM C 94, or the Specifications for Concrete Made by Volumetric
Batching and Continuous Mixing, ASTM C 685, as set forth in Chapter 35 of this
code.
1924.2.3 Job-mixed concrete shall be mixed in accordance
with the following:
1. Mixing
shall be done in a batch mixer of approved type.
2. Mixer
shall be rotated at a speed recommended by the manufacturer.
3. Mixing
shall be continued for at least 11/2 minutes after all materials are in the
drum, unless a shorter time is shown to be satisfactory by the mixing
uniformity test of Specification for Ready-Mixed Concrete, ASTM C 94.
4. Materials
handling, batching, and mixing shall conform to applicable provisions of the
Specifications for Ready-Mixed Concrete, ASTM C 94.
5. A
detailed record shall be kept to identify:
5.1. Number
of batches produced.
5.2. Proportions
of materials used.
5.3. Approximate
location of final deposit in structure.
5.4. Time
and date of mixing and placing.
[3- Covered in model base code] 1903
1924.3 Conveying.
1924.3.1 Concrete shall be conveyed from mixer to the
place of final deposit by methods that will prevent separation or loss of the
materials.
1924.3.2 Conveying equipment shall be capable of
providing a supply of concrete at the site of placement without separation of
ingredients and without interruptions sufficient to permit loss of plasticity
between successive increments.
[3- Covered in model base
code]1903
1924.4 Depositing.
1924.4.1 Concrete shall be deposited as nearly as
practicable in its final position to avoid segregation caused by rehandling or
flowing.
1924.4.2 Concreting shall be carried on at such a rate
that concrete is at all times plastic and flows readily into the spaces between
reinforcement.
1924.4.3 Concrete that has partially hardened or been
contaminated by foreign materials shall not be deposited in the structure.
1924.4.4 Retempered concrete or concrete that has been
remixed after initial set shall not be used unless approved by the building
official.
1924.4.5 After concreting is started, it shall be carried
on as a continuous operation until placing of the panel or section, as defined
by its boundaries or predetermined joints is completed except as permitted or
prohibited by Section 1925.4.
1924.4.6 Top surfaces of vertically formed lifts shall be
generally level.
1924.4.7 When construction joints are required, joints
shall be made in accordance with Section 1925.4.
1924.4.8 All concrete shall be thoroughly consolidated by
suitable means during placement and shall be thoroughly worked around the
reinforcement and embedded fixtures and into corners of forms.
[3- Covered in model base
code]1903
1924.5 Curing.
1924.5.1 Concrete, other than high-early-strength, shall
be maintained in a moist condition for as least the first seven days after
placement, except when cured in accordance with Section 1924.5.3.
1924.5.2 High-early-strength concrete shall be maintained
in a moist condition for at least the first three days, except when cured in
accordance with Section 1924.5.3.
[3- Covered in model base code]1903
1924.5.3 Accelerated curing.
1. Curing
by high-pressure steam, steam at atmospheric pressure, heat and moisture, or
other accepted processes, may be employed to accelerate strength gain and
reduce time of curing.
2. Accelerated
curing shall provide a compressive strength of the concrete at the load stage
considered at least equal to required design strength at that load stage.
3. The
curing process shall produce concrete with a durability at least equivalent to
the curing method of Section 1924.5.3, Items 1 or 2.
4. Supplementary
strength tests in accordance with Section 1923.2.3 may be required to ensure
that curing is satisfactory.
[3- Covered in model base
code]1903
1924.6 Bonding.
1924.6.1 Before fresh concrete is deposited or placed on
or against concrete which has hardened for 8 hours or longer, the forms shall
be retightened, the surface of the hardened concrete shall be cleaned of all
foreign matter and laitance, and dampened, but not saturated. Fresh concrete
shall not be deposited or placed on or against hardened concrete so dampened
before the surface is completely free of shiny spots indicating free moisture.
When the concrete against which fresh concrete will be placed is less than 8
hours old, all laitance, loose particles and dirt shall be removed.
1924.6.2 Where bonding of fresh to hardened concrete is
necessary, construction joints and joints between footings and walls or
columns, between walls or columns and beams or floors they support, and joints
in unexposed walls shall be accomplished by reinforcement, dowels, adhesives, mechanical
connectors or other approved methods. Hardened concrete at joints shall be
dampened, but not saturated, immediately prior to the placement of fresh
concrete.
[3- Covered in model base
code]1903
SECTION 1925
HIGH-VELOCITY HURRICANE ZONES— FORMWORK, EMBEDDED PIPES
AND CONSTRUCTION JOINTS
1925.1 Design of formwork.
1925.1.1 Forms shall be designed in accordance with ACI
347, Recommended Practice for Concrete Formwork.
1925.1.2 Forms shall result in a final structure that
conforms to shapes, lines and dimensions of the members as required by the
design drawings and specifications.
1925.1.3 Forms shall be substantial and sufficiently
tight to prevent leakage of mortar.
1925.1.4 Forms shall be properly braced or tied together
to maintain position and shape.
1925.1.5 Forms and their supports shall be designed so as
not to damage previously placed structures.
1925.1.6 Design of formwork shall include consideration
of the rate and method of placing concrete; construction loads, including vertical,
horizontal and impact loads; and special form requirements for construction of
shells, folded plates, domes, architectural concrete or similar types of
elements.
1925.1.7 Forms for prestressed concrete members shall be
designed and constructed to permit movement of the member without damage during
application of prestressing force.
[3- Covered in model base
code]1903
1925.2 Removal of forms and shores.
1925.2.1 No construction loads shall be supported on, nor
any shoring removed from, any part of the structure under construction except
when that portion of the structure in combination with the remaining forming
and shoring system has sufficient strength to safely support its weight and
loads placed thereon.
1925.2.2 Sufficient strength shall be demonstrated by
structural analysis considering proposed loads, strength of the forming and
shoring system and concrete strength data. Concrete strength data may be based
on tests of field-cured cylinders or, when approved by the building official,
on other procedures to evaluate concrete strength. Structural analysis and
concrete strength test data shall be furnished to the building official when so
required.
1925.2.3 No construction loads exceeding the combination
of superimposed dead load plus specified live load shall be supported on any
unshored portion of the structure under construction, unless analysis indicated
adequate strength to support such additional loads.
1925.2.4 Forms shall be removed in a manner that does not
impair the safety and serviceability of the structure. All concrete to be
exposed by form removal shall have sufficient strength not to be damaged
thereby.
1925.2.5 Form supports for prestressed concrete members
may be removed when sufficient prestressing has been applied to enable
prestressed members to carry their dead load and anticipated construction
loads.
[3- Covered in model base
code]1903
1925.3 Conduits and pipes embedded in concrete.
1925.3.1 Conduits, pipes and sleeves of any material not
harmful to concrete, and with limitations of this section, may be embedded in
concrete with approval of the professional engineer provided they are not
considered to structurally replace the displaced concrete.
1925.3.2 Conduits or pipes of aluminum shall not be
embedded in structural concrete unless effectively coated or covered to prevent
aluminum-concrete reaction or electrolytic action between aluminum and steel.
1925.3.3 Conduits, pipes and sleeves passing through a
slab, wall or beam shall not impair the strength of the construction.
1925.3.4 Conduits and pipes, with their fittings,
embedded within a column shall not displace more than 4 percent of the area of
cross section on which strength is calculated or which is required for fire
protection.
1925.3.5 Except when plans for conduits and pipes are
approved by the professional engineer and other than those merely passing
through, conduits and pipes embedded within a slab, wall or beam shall satisfy
the following:
1. They
shall not be larger in outside dimension than three-eights of the overall
thickness of slab, wall or beam in which they are embedded.
2. They
shall not be spaced closer than three diameters or widths on center.
3. They
shall not impair the strength of the construction.
1925.3.6 Conduits, pipes and sleeves may be considered as
replacing structurally in compression the displaced concrete, provided:
1. They
are not exposed to rusting or other deterioration.
2. They
are of uncoated or galvanized iron or steel not thinner than standard Schedule
40 steel pipe, and
3. They
have a nominal inside diameter not over 2 inches (51 mm) and are spaced not
less than three diameters on centers.
1925.3.7 In addition to other requirements of Section
1925.3 pipes that will contain liquid, gas or vapor may be embedded in
structural concrete under the following conditions:
1. Pipes and fittings shall be designed
to resist effects of the material, pressure and temperature to which they will
be subjected.
2. Temperature of liquid, gas or vapor
shall not exceed 150°F (66°C).
3. Maximum pressure to which any piping
or fittings shall be subjected shall not exceed 200 psi (1379 kPa) above
atmospheric pressure.
4. All piping and fittings except as
provided in Section 1925.3.5 shall be tested as a unit for leaks before
concrete placement. Testing pressure above atmospheric pressure shall be 50
percent in excess of pressure to which piping and fittings may be subjected,
but minimum testing pressure shall not be less than 150 psi (1034 kPa) above
atmospheric pressure. Pressure test shall be held for 4 hours with no drop in
pressure except that which may be caused by air temperature.
5. Drain pipes and other piping designed
for pressures of not more than 1 psi (7 kPa) above atmospheric pressure need
not be tested as required in Section 1925.3.7(4).
6. Pipes carrying liquid, gas or vapor
that is explosive or injurious to health shall be tested again as specified in
Section 1925.3.7(4) after concrete has hardened.
7. No liquid, gas or vapor, except water
not exceeding 90°F (32°C) nor 50 psi (350 kPa) pressure, shall be placed in the
pipes until the concrete has attained its design strength.
8. Unless piping in solid slabs is for
radiant heating, it shall be placed between top and bottom reinforcement.
9. Concrete cover for pipes and fittings
shall not be less than 11/2 inches (38 mm) for concrete exposed to earth or
weather, nor 3/4 inch (19 mm) for concrete not exposed to weather or in contact
with ground.
10. Reinforcement
with an area not less than 0.002 times the area of concrete section shall be
provided normal to the piping.
11. Piping
and fittings shall be assembled by welding, brazing, solder sweating or other
equally satisfactory methods. Screw connections shall not be permitted. Piping
shall be so fabricated and installed that cutting, bending or displacement of
reinforcement from its proper location will not be required.
[3- Covered in model base code]1903
1925.4 Construction joints.
1925.4.1 Surfaces of the concrete construction joints
shall be cleaned and laitance removed.
1925.4.2 Immediately before new concrete is placed, all
construction joints shall be wetted and standing water removed.
1925.4.3 Construction joints shall be so made and located
as not to impair the strength of the structure. Provision shall be made for
transfer of shear and other forces through construction joints.
1925.4.4 Construction joints in floors shall be located
near the middle of the spans of slabs, beams or girders, unless a beam
intersects a girder at the middle location, in which case, joints in the
girders shall be offset a distance approximately twice the width of the beam.
1925.4.5 Beams, girders or slabs supported by columns or
walls shall not be cast or erected until concrete in the vertical support
members is no longer plastic.
1925.4.6 Beams, girders, haunches, drop panels and
capitals shall be placed monolithically as part of a slab system, unless
otherwise shown on design drawing.
[3- Covered
in model base code]1903
SECTION 1926
HIGH-VELOCITY HURRICANE ZONES— DETAILS OF REINFORCEMENT
1926.1 Bending reinforcement.
1926.1.1 All reinforcement shall be bent cold, unless
otherwise permitted by the professional engineer.
1926.1.2 Reinforcement partially embedded in concrete shall
not be field bent, except as shown on the design drawings or permitted by the
professional engineer.
[3- Covered in model base code]1903
1926.2 Surface conditions of reinforcement.
1926.2.1 At the time concrete is placed, reinforcement
shall be free from mud, oil or other nonmetallic coatings that adversely affect
bonding capacity.
1926.2.2 Steel reinforcement, except prestressing
tendons, with rust, mill scale or a combination of both shall be considered
satisfactory, provided the minimum dimensions, including the height of
deformations and weight of a hand-wire-brushed test specimen, are not less than
applicable ASTM specification requirements.
1926.2.3 Prestressing tendons shall be clean and free of
oil, dirt, scale, pitting and excessive ruts. A light oxide is permissible.
[3- Covered in model base code]1903
1926.3 Placing reinforcement.
1926.3.1 Steel reinforcement shall be accurately placed
and adequately secured in position by concrete or metal chairs, spacers or
other acceptable methods. The minimum clear distance between parallel bars,
except in columns, shall be equal to the nominal diameter of the bars. In no
case shall the clear distance between bars be less than 1 inch (25 mm), or less
than one and one-third times the maximum size of the coarse aggregate. When
reinforcement in beams or girders is placed in two or more layers, the clear
distance between layers shall not be less than 1 inch (25 mm) nor less than the
diameter of the bars, and the bars in the upper layers shall be placed directly
above those in the bottom layer.
1926.3.2 Unless otherwise permitted by the building
official and professional engineer, reinforcement, prestressing tendons and
prestressing ducts shall be placed within the following tolerances:
1. Tolerance
for depth, d, and minimum concrete cover in flexural members, walls and
compression members shall be as follows, where d represents the distance from
the extreme compression fiber to the centroid of the tension reinforcement:
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Exceptions:
a. Tolerance
for the clear distance to formed soffits shall be minus 1/4 inch (6.3 mm).
b. Tolerance
for cover shall not exceed minus one-third the minimum concrete cover required
in the contract drawings nor less than 1 inch (25 mm) when exposed to weather.
2. Tolerance
for longitudinal location of bends and ends of reinforcement shall be + 2
inches (+ 51 mm) except at discontinuous ends of members where tolerance shall
be + 1/2 inch (+ 12.7 mm).
1926.3.3 Welded wire fabric with a wire size not greater
than W5 or D5 used in slabs not exceeding 10 feet (3 m) in span may be curved
from a point near the top of the slab over the support to a point near the
bottom of the slab at midspan, provided such reinforcement is either continuous
over, or securely anchored at, the support.
1926.3.4 Welding of crossing bars shall not be permitted
for assembly of reinforcement unless approved by the professional engineer of
record.
1926.3.5 Spacing limits and concrete cover for
reinforcement shall be shown on the design drawings.
[3- Covered in model base code]1903
1926.4 Splices in reinforcement.
1926.4.1 In slabs, beams and girders, splices in
reinforcement at points of maximum stress shall be avoided wherever possible.
Such splices, where used, shall be welded, lapped or otherwise fully developed,
but, in any case, shall transfer the entire stress from bar to bar without
exceeding the allowable bond and shear stresses. The minimum overlap for a
lapped splice shall be 24 bar diameters, but not less than 12 inches (25 mm)
for bars and in accordance with Section 12.15 and 12.16 of ACI 318. The clear
distance between bars shall also apply to the clear distance from a contact
splice and adjacent splices or bars.
1926.4.2 Reinforcement shall be spliced only as required
or permitted on design drawings, or in specifications or as authorized by the
professional engineer of record.
1926.4.3 Lap splices shall not be used for bars larger
than #11 except as provided in ACI 318.
1926.4.4 Lap splices of bundled bars shall be based on
the lap splice length required for individual bars within a bundle, increased
20 percent for a 3-bar bundle and 33 percent for a 4-bar bundle. Individual bar
splices within a bundle shall not overlap.
1926.4.5 Bars spliced by noncontact lap splices in
flexural members shall not be spaced transversely farther apart than one-fifth
the required lap splice length, nor 6 inches (152 mm).
1926.4.6 Welded splices may be used, provided the
metallurgical properties of the bars are suitable as determined by the
professional engineer of record in accordance with AWS D1.4.
1926.4.7 End bearing splices.
1926.4.7.1 In bars required for compression only,
compressive stress may be transmitted by bearing of square cut ends held in
concentric contact by a suitable device.
1926.4.7.2 Bar ends shall terminate in flat surfaces
within 11/2 degrees of a right angle to the axis of the bars and shall be
fitted within 3 degrees of full bearing after assembly.
1926.4.7.3 End bearing splices shall be used only in
members containing closed ties, closed stirrups or spirals.
1926.4.8 Welded splices in reinforcing bars shall be made
by certified welders and shall comply with the Standard Structural Welding
Code-Reinforcing Steel, AWS D1.4, as set forth in Chapter 35 of this code.
[3- Covered in model base code]1903
1926.5 Concrete protection for reinforcement
(nonprestressed).
1926.5.1 The reinforcement of footings and other
principal structural members in which the concrete is deposited against the
ground shall have not less than 3 inches (76 mm) of concrete between it and the
ground contact surface. If the concrete surfaces after removal of the forms are
to be exposed to the weather or be in contact with the ground, the
reinforcement shall be protected with not less than 2 inches (51 mm) of
concrete for bars larger than No. 5 and 11/2 inches (38 mm) for No. 5 bars or
smaller except as set forth in Section 1926.5.5.
1926.5.2 The concrete protective covering for
reinforcement at surfaces not exposed directly to the ground or weather shall
be not less than 3/4 inch (19 mm) for slabs and wall; and not less than 11/2
inches (38 mm) for beams, girders and columns. In concrete ribbed floors in
which the clear distance between ribs is not more than 30 inches (762 mm), the
protection of reinforcement shall be at least 3/4 inch (19 mm).
1926.5.3 Concrete protection for reinforcement shall in
all cases be as least equal to the diameter of bars except for concrete slabs
and joists as set forth herein.
1926.5.4 Exposed reinforcement bars intended for bonding
with future extensions shall be protected from corrosion by concrete or other
adequate covering.
1926.5.5 For exterior balcony slabs, slab surface shall
be sloped 1/8 unit in 12 units or greater to safeguard against ponding of water
and slabs shall be designed and constructed in accordance with the provisions
of ACI 318.
1926.5.6 Concrete cover for cast-in-place, precast and
prestressed concrete shall be in accordance with ACI 318 if not otherwise
specified in this section. When this code requires a thickness of cover for
fire protection greater than the minimum concrete specified in ACI 318, the
greater thickness shall be used.
1926.5.7 Exposed reinforcement, inserts and plates
intended for bonding with future extensions shall be protected from corrosion.
[3- Covered
in model base code]1903
SECTION 1927
HIGH-VELOCITY
HURRICANE ZONES— PRECAST CONCRETE UNITS
1927.1 General.
1927.1.1 Precast concrete units shall comply with the minimum requirements set forth in this section, and the standard set forth in Section 1920.3.
1927.1.2 All precast concrete elements and their attachments (including imbedments) to the main structural frame shall be designed by, and bear the seal of a Florida-registered architect or a Florida-registered engineer, which architect or engineer shall be proficient in structural design. The design shall be based on rational analysis for loads set forth in Chapter 16 (High-Velocity Hurricane Zones). The architect/engineer of record may delegate this responsibility to a Florida-registered delegated engineer. In that case, shop drawings and design calculations prepared by such delegated engineer shall be reviewed and approved by the architect and the engineer of record.
1927.1.3 Only the material cast monolithically with the units at the time of manufacture shall be used in computing stresses unless adequate and approved shear transfer is provided.
1927.1.4 The building official may promulgate and set forth in writing such reasonable rules for requiring tests to be made by an approved laboratory as he may consider necessary to insure compliance with this code or uniformity of the products produced. The quantity of tests shall be based on consideration of safety or volume of output.
1927.1.5 The building official or his or her representative shall have free access to the plant of any producer at all hours of normal operation, and failure to permit such access shall be cause for revocation of approval.
1927.1.6 Failure of any product to satisfy in every respect the quality prescribed, or failure to conform with plans and specifications, shall be cause for rejection of the products.
1927.2 Statements of responsibilities of architects and professional engineers on design of structures using precast concrete components.
1927.2.1 The structural construction documents shall indicate the configuration of precast components and shall include details of supports, anchors and connections for those components. Permit documents shall include sufficient details describing the attachment of precast units (including embedments) to the main structure.
1927.2.2 The precast permit documents shall bear the signature and seal of the professional architect or engineer charged with the responsibility of the design of the precast units. The architect or engineer of record may delegate this responsibility to a Florida-registered delegated engineer. In that case, shop drawings and design calculations prepared by such delegated engineer shall be reviewed and approved by the architect and/or the engineer of record as an indication that his or her intent has been understood and that the specified criteria have been used.
1927.2.3 The structural submittals shall include component details, calculations and fabrication and erection drawings. All such submittals shall identify the specific project.
1927.3 Aggregate. The maximum size of the aggregate for precast units shall be not larger than one-third of the narrowest dimension between sides of the forms of the member in which the unit is cast nor larger than three-fourths of the minimum clear spacing between reinforcing bars and sides of the forms, except that where concrete is placed by means of high frequency vibration, the maximum size of the aggregate shall not be larger than one-half of the narrowest dimension between sides of the form.
1927.4 Strength of concrete.
1927.4.1 Concrete for precast structural units made of
crushed stone or other heavy aggregate shall have a compressive strength of not
less than 2,500 psi (17 238 kPa) at 28 days.
1927.4.2 Concrete for precast units made of light weight
aggregate concrete shall follow the general provisions of Section 1923.1.2 with
consideration of the nature and limitations of the aggregate and the strength
of the product.
[3- Covered in model base code]1903
1927.5 Workmanship.
1927.5.1 The mix, the gradation of the aggregate and the
workability shall be such as to insure complete filling of the form and
continuous intimate bond between the concrete and all steel.
1927.5.2 Handling and conveying before curing shall be
reduced to a minimum. Machinery for this purpose should be so designed that the
unit will not be subject to bending or shock which would produce incipient
cracks or broken edges or corners. Precast units shall not be freely
transported or placed until the concrete is at least 14 days old, if made with
regular cement, or at least seven days old, if made with Type III cement, or
until its strength, as established by definite tests, is at least 60 percent of
the required 28-day strength.
[3- Covered
in model base code]1903
1927.5.3 The use of precast structural units not complying with ACI requirements or having visible cracks, honeycomb, exposed reinforcing except at ends or, with a compressive section dimension more than 1/8 inch (3.1 mm) less than specified dimension shall not be permitted.
1927.6 Curing.
1927.6.1 No precast structural unit shall be removed from
the form until the concrete has attained a compressive strength of 50 percent
of the 28-day design strength but not less than 1,250 psi (8619 kPa) as
verified by representative tests.
1927.6.2 Curing by high pressure steam, steam vapor or
other accepted processes may be employed to accelerate the hardening of the
concrete and to reduce the time of curing.
[3- Covered
in model base code]1903
1927.6.3 To ensure the eventual placement of the units in the structure without damage, the handling shall be done in such a manner that bending shall be reduced to a minimum or prevented.
1927.7 Identification and marking. All joists, beams,
girders and other units shall show some mark plainly indicating the top of the
unit. This mark or symbol shall indicate the manufacturer, the date of
manufacture and the length, size and type of reinforcing.
[3- Covered
in model base code]1903
1927.8 Cutting of holes. No openings or channels not provided for in the structural design shall be made on the job without the specific approval of the professional engineer in accordance with his or her written, detailed instructions covering such work.
1927.9 Anchorage. Anchorage of all precast concrete units
shall be designed, based on rational analysis, to transmit loads and other
forces to the structural frame.
[3- Covered
in model base code]1903
1927.10 Bridging. Joists shall be secured against lateral displacement by cast-in-place bridging, and such bridging shall be spaced not to exceed 32 times the width of the compression flange of the joist except that for roof systems, cast-in-place portland-concrete slabs embedding the top flanges not less than 1/2 inch (12.7 mm), or steel inserts cast in the joist heads to which bulb-tees supporting gypsum decks are welded, shall be accepted in lieu of bridging.
1927.11 Connections. All joints and connections will
perform their function at all stages of loading without overstress and with
proper safety factors against failure caused by overload. Loading conditions to
be considered in the design of joints and connections are service loads,
including wind forces, volume changes resulting from shrinkage, creep, and
temperature change, reaction loads, and loading encountered in stripping forms,
shoring and removal of shores, storage and transportation of members.
[3- Covered
in model base code]1903
1927.12 Inspections.
1927.12.1 All structural precast units shall be inspected for quality control by an architect or professional engineer qualified to perform these inspections prior to the concrete placement at the casting yard.
1927.12.2 All structural precast units and their attachments to the main structure shall be inspected after erection, but before concealment. Such inspections shall be performed by a Florida registered architect or professional engineer.
SECTION 1928
HIGH-VELOCITY
HURRICANE ZONES — PRESTRESSED CONCRETE
1928.1 Prestressed concrete, as defined in Section 1921, shall
comply with this section.
[3- Covered
in model base code]1903
1928.1.1 All prestressed structural items shall be designed by a registered professional engineer. Openings or channels not provided for in the structural design shall not be made on the job without the specific approval of the design professional engineer.
1928.1.2 The building official may promulgate and set forth in writing such reasonable rules for requiring tests to be made by an approved laboratory as he or she may consider necessary to insure compliance with this code or uniformity of the products produced.
1928.1.3 The building official or his or her representative shall have free access to the plant of any producer at all hours of normal operation. Failure to permit such access shall be cause for revocation of approval.
1928.1.4 Failure of any product to satisfy the quality prescribed or failure to conform to plans and specifications shall be cause for rejection of the product.
1928.2 Statements of responsibilities of architects and professional engineers on design of cast-in-place post-tensioned concrete structural systems.
1928.2.1 The structural construction documents shall show the magnitude and location of all prestressing forces and all design assumptions.
1928.2.2 The structural engineer of record and/or the architect of record shall require the submission of calculations and installation drawings from a specialty engineer for post-tensioning systems for review by the structural engineer of record and/or the architect of record. Review is an indication that his or her intent has been understood and that the specified criteria have been used. The installation drawings shall provide full details of materials to be used including necessary accessories and instructions for construction and shall identify the specific project and shall bear the impressed seal, signature and date of the specialty engineer who prepared them.
1928.2.3 It is the responsibility of the structural engineer of record and/or the architect of record to review the post-tensioning system installation drawings so that the drawings are coordinated with the reinforcing steel shop drawings.
1928.2.4 Determining the effect of post-tensioning on other parts of the building is the responsibility of the structural engineer of record and/or the architect of record.
1928.3 Design and construction.
1928.3.1 Design and construction shall be in accordance
with Chapter 18 of ACI 318.
1928.3.2 Calcium chloride shall not be used in concrete
for prestressed members.
[3- Covered in model base
code]1903
1928.4 Tendon and anchorage zones.
1928.4.1 Reinforcement shall be provided where required
in tendon anchorage zones to resist bursting, splitting, and spalling forces
induced by tendon anchorage. Regions of abrupt change in section shall be
adequately reinforced.
1928.4.2 End blocks shall be provided where required for
support bearing or for distribution of concentrated prestressing forces.
1928.4.3 Post-tensioning anchorage and supporting
concrete shall be designed to resist maximum jacking force for strength of
concrete at time of prestressing.
1928.4.4 Post-tensioning anchorage zones shall be
designed to develop the guaranteed ultimate tensile strength of prestressing
tendons using a strength reduction factor of 0.90 for concrete.
[3- Covered in model base
code]1903
1928.5 Corrosion protection for unbonded prestressing
tendons.
1928.5.1 Unbonded tendons shall be completely coated with
suitable material to ensure corrosion protection.
1928.5.2 Tendon wrapping shall be continuous over the
entire length to be unbonded, and shall prevent intrusion of cement paste or
loss of coating materials during concrete placement.
[3- Covered in model base
code]1903
1928.6 Post-tensioning ducts.
1928.6.1 Ducts for grouted or unbonded tendons shall be
mortar-tight and nonreactive with concrete, tendons or filler material.
1928.6.2 Ducts for grouted single wire, strand or bar
tendons shall have an inside diameter at least 1/4 inch (6.3 mm) larger than
tendon diameter.
1928.6.3 Ducts for grouted multiple wire, strand or bar
tendons shall have an inside cross-sectional area at least two times the net
area of the tendons.
[3- Covered in model base
code]1903
1928.7 Grout for prestressing tendons.
1928.7.1 Grout shall consist of portland cement and
water; or Portland cement, sand and water.
1928.7.2 Materials for grout shall conform as specified
in ACI 318 and be as follows:
1. Portland
cement.
2. Water
content shall be minimum necessary for proper pumping of grout; however,
water-cement ratio shall not exceed 0.45 by weight.
3. Sand,
if used, shall conform to Standard Specifications for Aggregate for Masonry
Mortar, ASTM C 144, except that gradation may be modified as necessary to
obtain satisfactory workability.
4. Admixtures
conforming to ACI 318 and known to have no injurious effects on grout, steel or
concrete may be used. Calcium chloride shall not be used.
5. Water
shall not be added to increase grout flowability that has been decreased by
delayed use of grout.
6. Grout
temperatures shall not be above 90°F (32°C) during mixing and pumping.
[3- Covered
in model base code]1903
1928.8 Protection for prestressing tendons. Burning or
welding operations in the vicinity of prestressing tendons shall be carefully
performed, so that tendons are not subject to excessive temperatures, welding
sparks or ground currents.
[3- Covered in model base
code]1903
1928.9 Application and measurement of prestressing force.
1928.9.1 Prestressing force shall be determined by both
of the following methods and the cause of any difference in force determination
that exceeds 5 percent shall be ascertained and corrected.
1. Measurement
of tendon elongation. Required elongation shall be determined from average
load-elongation curves for prestressing tendons used.
2. Observation
of jacking force on a calibrated gauge or load cell or by use of a calibrated
dynamometer.
1928.9.2 Where transfer of force from bulkheads or
pretensioning bed to concrete is accomplished by flame cutting prestressing
tendons, cutting points and cutting sequence shall be predetermined to avoid
undesired temporary stresses.
1928.9.3 Long lengths of exposed pretensioned strand
shall be cut near the member to minimize shock to concrete.
1928.9.4 Total loss of prestress as a result of
unreplaced broken tendons shall not exceed 2 percent of total prestress.
[3- Covered in model base
code]1903
1928.10 Post-tensioning anchorages and couplers.
1928.10.1 Couplers shall be placed in areas approved by
the professional engineer and enclosed in housing long enough to permit
necessary movements.
1928.10.2 In unbonded construction subject to repetitive
loads, special attention shall be given to the possibility of fatigue in
anchorages and couplers.
1928.10.3 Anchorage and end fittings shall be permanently
protected against corrosion.
[3- Covered in model base
code]1903
SECTION 1929
HIGH-VELOCITY HURRICANE ZONES— PNEUMATICALLY PLACED
CONCRETE (SHOTCRETE)
1929.1 General.
1929.1.1 Pneumatically placed concrete is a proportioned
combination of fine aggregate portland cement and water which, after mixing, is
pneumatically projected by air directly onto the surface to which it is to be
applied.
1929.1.2 Pneumatically placed concrete shall conform to
all requirements of Specifications for Materials, Proportioning and Application
of Shotcrete, ACI 506.2 published by the American Concrete Institute, except as
modified herein.
1929.1.3 Pneumatically placed concrete shall be composed
of Portland cement, aggregate and water proportioned to produce a concrete suitable
for pneumatic application.
1929.1.4 Concrete ingredients shall be selected and
proportioned in a manner that will produce concrete which will be extremely
strong, dense and resistant to weathering and abrasion.
[3- Covered in model base code]1903
1929.2 Sampling and testing cement and aggregate. The
contractor shall determine the source, kind and quality of the cement and
aggregates to be used in the work well in advance of the time scheduled for
starting the work and when so directed by the building official shall submit
such information for approval before starting shotcrete operation.
[3- Covered in model base code]1903
1929.3 Surface preparation. To insure adequate bond, the
newly chipped and sandblasted surface shall be thoroughly moistened with water
prior to application of shotcrete. In no instance shall shotcrete be applied in
an area where free running water exists.
[3- Covered in model base code]1903
1929.4 Proportioning. Prior to the start of shotcreting,
the contractor shall submit to the professional engineer the recommended mix as
a ratio of cement to aggregate. The recommended mix shall be on the basis of
test data from prior experience.
[3- Covered in model base code]1903
1929.5 Mixing.
1929.5.1 Shotcrete shall be thoroughly mixed by machine
and then passed through a sieve to remove all large particles before placing in
the hopper of the cement gun. The mixture shall not be permitted to become
damp. Each batch should be entirely discharged before recharging is begun. The
mixer should be cleaned thoroughly enough to remove all adherent materials from
the mixing vanes and from the drum at regular intervals.
1929.5.2 Water in any amount shall not be added to the
mix before it enters the cement gun. Quantities of water shall be controlled by
a valve at the nozzle of the gun. Water content shall be adjusted as required
for proper placement, but shall in no case exceed 4 gallons (15 L) of water per
sack of cement, including the water contained in the aggregate.
1929.5.3 Remixing or tempering shall not be permitted.
Mixed material that has stood 45 minutes without being used shall be discarded.
Rebound materials shall not be reused.
[3- Covered in model base code]1903
1929.6 Application.
1929.6.1 In shooting walls and columns, application shall
begin at the bottom and the first coat shall completely embed the reinforcement
to the form.
1929.6.2 In shooting beams, application shall begin at
the bottom and a surface at right angles to the nozzle shall be maintained.
1929.6.3 In shooting slabs, the nozzle shall be held at a
slight angle to the work so that rebound is blown on to the finished portion
where it shall be removed.
1929.6.4 Corners shall be filled first.
"Shooting" shall be from an angle as near perpendicular to the surface
as practicable, with the nozzle held approximately 3 feet (915 mm) from the
work, except in confined control. If the flow of material at the nozzle is not
uniform and slugs, sand spots or wet sloughs result, the nozzle person shall
direct the nozzle away from the work until the faulty conditions are corrected.
Such defects shall be replaced as the work progresses.
1929.6.5 Shotcreting shall be suspended if:
1. Air
velocity separates the cement from the sand at the nozzle.
2. Temperature
approaches freezing and the newly placed shotcrete cannot be protected.
1929.6.6 The time interval between successive layers in
sloping, vertical or overhanging work must be sufficient to allow initial but
not final set to develop. At the time the initial set is developing, the
surface shall be cleaned to remove the thin film of laitance in order to
provide a good bond with succeeding applications.
[3- Covered in model base code]1903
1929.7 Construction joints. Construction joints or day's
work joints shall be sloped off to a thin, clean, regular edge, preferably at a
45 degree (0.78 rad) slope. Before placing the adjoining work, the slope
portion and adjacent shotcrete shall be thoroughly cleaned as necessary, then
moistened and scoured with an air jet.
[3- Covered in model base code]1903
1929.8 Curing and protection.
1929.8.1 Curing shall be in accordance with ACI 506.2
depending upon atmospheric condition.
1929.8.2 Immediately after placement, shotcrete shall be
maintained in a moist condition for at least the first 24 hours.
1929.8.3 Final curing shall continue for seven days after
placement if Type I Portland cement is used, or for three days if
high-early-strength Type III Portland cement is used, or until the specified
strength is attained. Final curing may consist of the initial curing process or
an approved moisture-retaining covering.
1929.8.4 Natural curing may be used when relative
humidity remains above 85 percent when approved by the professional engineer of
record.
[3- Covered in model base
code]1903