USACE / NAVFAC / AFCESA / NASA UFGS-03 40 00.00 10 (August 2006)
---------------------------------
Preparing Activity: USACE Superseding
UFGS-03 40 00.00 10 (July 2006)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 03 40 00.00 10
PLANT-PRECAST CONCRETE PRODUCTS FOR BELOW GRADE CONSTRUCTION
08/06
NOTE: This guide specification covers the requirements for precast, non-prestressed
concrete products used for below grade construction (Sewage Systems, Subdrainage
Systems, Storm Drainage Systems, Utility and Communications Structures, etc..
Edit this guide specification for project specific requirements by adding, deleting,
or revising text. For bracketed items, choose applicable items(s) or insert
appropriate information.
Remove information and requirements not required in respective project, whether
or not brackets are present.
Comments and suggestions on this guide specification are welcome and should
be directed to the technical proponent of the specification. A listing of technical
proponents, including their organization designation and telephone number, is
on the Internet.
Recommended changes to a UFGS should be submitted as a Criteria Change Request
(CCR).
PART 1 GENERAL
1.1 REFERENCES
NOTE: This paragraph is used to list the publications cited in the text of
the guide specification. The publications are referred to in the text by basic
designation only and listed in this paragraph by organization, designation,
date, and title.
Use the Reference Wizard's Check Reference feature when you add a RID outside
of the Section's Reference Article to automatically place the reference in the
Reference Article. Also use the Reference Wizard's Check Reference feature
to update the issue dates.
References not used in the text will automatically be deleted from this section
of the project specification when you choose to reconcile references in the
publish print process.
The publications listed below form a part of this specification to the extent referenced. The publications are
referred to within the text by the basic designation only.
[ACI INTERNATIONAL (ACI)ACI 211.1(1991; R 2002) Standard Practice for Selecting Proportions for Normal, Heavyweight, and Mass ConcreteACI 211.2(1998; R 2004) Standard Practice for Selecting Proportions for Structural Lightweight ConcreteACI 305R(1999; Errata 2006) Hot Weather ConcretingACI 306.1(1990; R 2002) Standard Specification for Cold Weather ConcretingACI 318(2008; Errata 2008) Building Code Requirements for Structural Concrete and CommentaryACI 318M(2008) Metric Building Code Requirements for Structural Concrete and Commentary][AMERICAN CONCRETE PIPE ASSOCIATION (ACPA)ACPA 01-102(2000) Concrete Pipe HandbookACPA 01-110(1984) Design Manual for Sulfide and Corrosion Prediction and ControlACPA QPC(2005; Ver 3.0) QCast Plant Certification Manual][AMERICAN WELDING SOCIETY (AWS)AWS D1.1/D1.1M(2008) Structural Welding Code - SteelAWS D1.4/D1.4M(2005; Errata 2005) Structural Welding Code - Reinforcing Steel][ASTM INTERNATIONAL (ASTM)ASTM A 153/A 153M(2005) Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel HardwareASTM A 185/A 185M(2007) Standard Specification for Steel Welded Wire Reinforcement, Plain, for ConcreteASTM A 36/A 36M(2008) Standard Specification for Carbon Structural SteelASTM A 496/A 496M(2007) Standard Specification for Steel Wire, Deformed, for Concrete ReinforcementASTM A 497/A 497M(2007) Standard Specification for Steel Welded Wire Reinforcement, Deformed, for ConcreteASTM A 615/A 615M(2008b) Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete ReinforcementASTM A 706/A 706M(2008a) Standard Specification for Low-Alloy Steel Deformed and Plain Bars for Concrete ReinforcementASTM A 767/A 767M(2005) Standard Specification for Zinc-Coated (Galvanized) Steel Bars for Concrete ReinforcementASTM A 775/A 775M(2007b) Standard Specification for Epoxy-Coated Steel Reinforcing BarsASTM A 82/A 82M(2007) Standard Specification for Steel Wire, Plain, for Concrete ReinforcementASTM A 884/A 884M(2006) Standard Specification for Epoxy-Coated Steel Wire and Welded Wire ReinforcementASTM C 1064/C 1064M(2008) Standard Test Method for Temperature of Freshly Mixed Hydraulic-Cement ConcreteASTM C 1107/C 1107M(2008) Standard Specification for Packaged Dry, Hydraulic-Cement Grout (Nonshrink)ASTM C 1116/C 1116M(2008) Standard Specification for Fiber-Reinforced ConcreteASTM C 1240(2005) Standard Specification for Silica Fume Used in Cementitious MixturesASTM C 1244(2005e1) Standard Test Method for Concrete Sewer Manholes by the Negative Air Pressure (Vacuum) Test Prior to BackfillASTM C 1244M(2005e1) Standard Test Method for Concrete Sewer Manholes by the Negative Air Pressure (Vacuum) Test Prior to Backfill (Metric)ASTM C 138/C 138M(2008) Standard Test Method for Density ("Unit Weight"), Yield, and Air Content (Gravimetric) of ConcreteASTM C 143/C 143M(2008) Standard Test Method for Slump of Hydraulic-Cement ConcreteASTM C 1478(2008) Standard Specification for Storm Drain Resilient Connectors Between Reinforced Concrete Storm Sewer Structures, Pipes and LateralsASTM C 1478M(2008a) Standard Specification for Storm Drain Resilient Connectors Between Reinforced Concrete Storm Sewer Structures, Pipes and Laterals (Metric)ASTM C 150(2007) Standard Specification for Portland CementASTM C 171(2007) Standard Specification for Sheet Materials for Curing ConcreteASTM C 173/C 173M(2008) Standard Test Method for Air Content of Freshly Mixed Concrete by the Volumetric MethodASTM C 192/C 192M(2007) Standard Practice for Making and Curing Concrete Test Specimens in the LaboratoryASTM C 231(2008c) Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure MethodASTM C 260(2006) Standard Specification for Air-Entraining Admixtures for ConcreteASTM C 309(2007) Standard Specification for Liquid Membrane-Forming Compounds for Curing ConcreteASTM C 31/C 31M(2008a) Standard Practice for Making and Curing Concrete Test Specimens in the FieldASTM C 33(2007) Standard Specification for Concrete AggregatesASTM C 330(2005) Standard Specification for Lightweight Aggregates for Structural ConcreteASTM C 39/C 39M(2005e1e2) Standard Test Method for Compressive Strength of Cylindrical Concrete SpecimensASTM C 443(2005a) Standard Specification for Joints for Concrete Pipe and Manholes, Using Rubber GasketsASTM C 443M(2007) Standard Specification for Joints for Concrete Pipe and Manholes, Using Rubber Gaskets (Metric)ASTM C 494/C 494M(2008a) Standard Specification for Chemical Admixtures for ConcreteASTM C 595(2008) Standard Specification for Blended Hydraulic CementsASTM C 618(2008a) Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in ConcreteASTM C 877(2008) External Sealing Bands for Concrete Pipe, Manholes, and Precast Box SectionsASTM C 877M(2002; E 2005) External Sealing Bands for Concrete Pipe, Manholes, and Precast Box Sections (Metric)ASTM C 891(1990; R 2003) Installation of Underground Precast Concrete Utility StructuresASTM C 920(2008) Standard Specification for Elastomeric Joint SealantsASTM C 923(2008) Standard Specification for Resilient Connectors Between Reinforced Concrete Manhole Structures, Pipes and LateralsASTM C 923M(2008b) Standard Specification for Resilient Connectors Between Reinforced Concrete Manhole Structures, Pipes and Laterals (Metric)ASTM C 989(2006) Standard Specification for Ground Granulated Blast-Furnace Slag for Use in Concrete and MortarsASTM C 990(2008) Standard Specification for Joints for Concrete Pipe, Manholes and Precast Box Sections Using Preformed Flexible Joint SealantsASTM C 990M(2008) Standard Specification for Joints for Concrete Pipe, Manholes and Precast Box Sections Using Preformed Flexible Joint Sealants (Metric)][CANADIAN STANDARDS ASSOCIATION (CSA)CAN/CSA A23.4(2005) Precast Concrete - Materials and Construction][NATIONAL PRECAST CONCRETE ASSOCIATION (NPCA)NPCA QC Manual(2005; R 2006) Quality Control Manual for Precast Plants]1.2 SUBMITTALS
NOTE: Review submittal description (SD) definitions in Section 01 33 00 SUBMITTAL
PROCEDURES and edit the following list to reflect only the submittals required
for the project. Submittals should be kept to the minimum required for adequate
quality control.
A “G” following a submittal item indicates that the submittal requires Government
approval. Some submittals are already marked with a “G”. Only delete an existing
“G” if the submittal item is not complex and can be reviewed through the Contractor’s
Quality Control system. Only add a “G” if the submittal is sufficiently important
or complex in context of the project.
For submittals requiring Government approval on Army projects, a code of up
to three characters within the submittal tags may be used following the "G"
designation to indicate the approving authority. Codes for Army projects using
the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO"
for District Office (Engineering Division or other organization in the District
Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project
Office. Codes following the "G" typically are not used for Navy, Air Force,
and NASA projects.
Choose the first bracketed item for Navy, Air Force and NASA projects, or choose
the second bracketed item for Army projects.
All submittals are the responsibility of the precast concrete producer. Government approval is required for
submittals with a "G" designation; submittals not having a "G" designation are for [Contractor Quality Control
approval.][information only. When used, a designation following the "G" designation identifies the office that
will review the submittal for the Government.] Submit the followingin accordance with Section 01 33 00 SUBMITTAL
PROCEDURES:
SD-01 Preconstruction Submittals
Quality Control Procedures
Quality control procedures established by the precast manufacturer in accordance with NPCA QC Manual
and/or ACPA QPC.
SD-02 Shop Drawings
Standard Precast Units[; G][; G, [_____]]
Drawings for standard precast concrete units furnished by the precast concrete producer for
approval by the Contracting Officer. These drawings shall demonstrate that the applicable industry
design standards have been met. Include installation and construction information on shop drawings.
Include details of steel reinforcement size and placement as well as supporting design calculations,
if appropriate. Produce precast concrete units in accordance with the approved drawings.
Custom-Made Precast Units[; G][; G, [_____]]
Drawings for custom-made precast concrete units furnished by the precast concrete producer
for approval by the Contracting Officer. Show on these drawings complete design, installation,
and construction information in such detail as to enable the Contracting Officer to determine
the adequacy of the proposed units for the intended purpose. Include details of steel reinforcement
size and placement as well as supporting design calculations, if appropriate. Produce precast
concrete units in accordance with the approved drawings.
SD-03 Product Data
Standard Precast Units
Cut sheets, for standard precast concrete units, showing conformance to project drawings and
requirements, and to applicable industry design standards listed in this specification.
Proprietary Precast Units
Standard plans or informative literature, for proprietary precast concrete units. Make available
supporting calculations and design details upon request. Provide sufficient information as
to demonstrate that such products will perform the intended task.
Embedded Items
Product data sheets and proper installation instruction for anchors, lifting inserts and other
devices. Clearly indicate the products dimensions and safe working load.
Accessories
Proper installation instructions and relevant product data for items including, but not limited
to, sealants, gaskets, connectors, steps, cable racks and other items installed before or after
delivery.
SD-05 Design Data
Design Calculations
Concrete Mix Proportions
Precast concrete unit design calculations, and concrete mix proportions.
SD-06 Test Reports
Test Reports
a. Copies of material certifications and/or laboratory test reports, including mill tests
and all other test data, for portland cement, blended cement, pozzolans, ground granulated blast
furnace slag, silica fume, aggregate, admixtures, and curing compound proposed for use on this
project.
b. Copies of test reports showing that the mix has been successfully tested to produce concrete
with the properties specified and will be suitable for the job conditions. Such tests may include
compressive strength, flexural strength, plastic or hardened air content, freeze thaw durability,
abrasion and absorption. Clearly detail in the specifications special tests for precast concrete
or cast-in items.
c. Sufficient documentation, when the use of self-consolidating concrete (SCC) is proposed,
showing a minimum of 30-days production track records demonstrating that SCC is appropriate
for casting of the product.
d. Copies of in-plant QA/QC inspection reports, upon the request of the Contracting Officer.
SD-07 Certificates
Quality Control Procedures
Quality control procedures established in accordance with NPCA QC Manual and/or ACPA QPC.
1.3 GENERAL REQUIREMENTS
Furnish precast concrete units designed and fabricated by an experienced and acceptable precast concrete manufacturer
who has been, for at least 3 years, regularly and continuously engaged in the manufacture of precast concrete
work similar to that indicated on the drawings. Coordinate precast work with the work of other trades.
1.4 DESIGN
1.4.1 Standard Precast Units
Design standard precast concrete units to withstand indicated design load conditions in accordance with applicable
industry design standards [ACI 318MACI 318, ASTM, ACPA 01-102, Chapter 7-Design for Sulfide Control]. Design
must also consider stresses induced during handling, shipping and installation as to avoid product cracking or
other handling damage. Indicate design loads for precast concrete units on the shop drawings.
1.4.2 Custom-Made Precast Units
Submit design calculations and drawings of custom-made precast units, prepared and sealed by a registered professional
engineer, for approval prior to fabrication. Include in the calculations the analysis of units for lifting stresses
and the sizing of lifting devices.
1.4.3 Proprietary Precast Units
Products manufactured under franchise arrangements must conform to all the requirements specified by the franchiser.
Items not included in the franchise specification, but included in this specification, must conform to the requirements
in this specification.
1.4.4 Joints and Sealants
Provide joints and sealants between adjacent units of the type and configuration indicated on shop drawings meeting
specified design and performance requirements.
1.4.5 Concrete Mix Design
1.4.5.1 Concrete Mix Proportions
Base selection of proportions for concrete on the methodology presented in ACI 211.1 for normal weight concrete
and ACI 211.2 for lightweight concrete. Develop the concrete proportions using the same type and brand of cement,
the same type and brand of pozzolan, the same type and gradation of aggregates, and the same type and brand of
admixture that will be used in the manufacture of precast concrete units for the project. Do not use calcium
chloride in precast concrete containing reinforcing steel or other embedded metal items. At a minimum of thirty
days prior to precast concrete unit manufacturing, the precast concrete producer will submit a mix design for
each strength and type of concrete that will be used. Furnish a complete list of materials, including quantity,
type, brand and applicable data sheets for all mix design constituents as well as applicable reference specifications.
The use of self-consolidating concrete is permitted, provided that mix design proportions and constituents meet
the requirements of this specification.
1.4.5.2 Concrete Strength
Provide precast concrete units with a 28-day compressive strength (f'c) of [_____] MPa psi.
1.4.5.3 Water-to-Cement Ratio
Furnish concrete, that will be exposed to freezing and thawing, containing entrained air and with water-cement
ratios of 0.45 or less. Furnish concrete which will not be exposed to freezing, but which is required to be
watertight, with a water-cement ratio of 0.48 or less if the concrete is exposed to fresh water, or 0.45 or less
if exposed to brackish water or sea water. Furnish reinforced concrete exposed to deicer salts, brackish water
or seawater with a water-cement ratio of 0.40 or less for corrosion protection.
1.4.5.4 Air Content
The air content of concrete that will be exposed to freezing conditions must be within the limits given below.
NOMINAL MAXIMUM AIR CONTENT %
AGGREGATE SIZE SEVERE EXPOSURE MODERATE EXPOSURE
10 mm (3/8 inch) 6.0 to 9.0 4.5 to 7.5
13 mm (1/2 inch) 5.5 to 8.5 4.0 to 7.0
19 mm (3/4 inch) 4.5 to 7.5 3.5 to 6.5
25 mm (1.0 inch) 4.5 to 7.5 3.0 to 6.0
38 mm (1.5 inch) 4.5 to 7.0 3.0 to 6.0
Note: For specified compressive strengths greater than 34.5 MPa 5000 psi, air content may be reduced 1%
1.4.5.5 Corrosion Control for Sanitary Sewer Systems
Follow design recommendations outlined in Chapter 7 of ACPA 01-102 or the ACPA 01-110 when hydrogen sulfide is
indicated as a potential problem.
1.5 QUALITY ASSURANCE
Demonstrate adherence to the standards set forth in NPCA QC Manual and/or ACPA QPC. Meet requirements written
in the subparagraphs below.
1.5.1 NPCA and ACPA Plant Certification
NOTE: The use of this paragraph may limit competition. Verify the availability
of NPCA and ACPA certified precasters in the bidding area.
The precast concrete producer shall be certified by the National Precast Concrete Association's and/or the American
Concrete Pipe Association's Plant Certification Program prior to and during production of the products for this
project.
1.5.2 Qualifications, Quality Control and Inspection
1.5.2.1 Qualifications
Select a precast concrete producer that has been in the business of producing precast concrete units similar
to those specified for a minimum of 3 years. The precast concrete producer must maintain a permanent quality
control department or retain an independent testing agency on a continuing basis.
1.5.2.2 Quality Control Procedures
Show that the following QC tests are performed as required and in accordance with the ASTM standards indicated.
a. Slump: Perform a slump test for each 115 cubic m 150 cu yd of concrete produced, or once a day, whichever
comes first. Perform slump tests in accordance with ASTM C 143/C 143M.
b. Temperature: Measure the temperature of fresh concrete when slump or air content tests are made and
when compressive test specimens are made in accordance with ASTM C 1064/C 1064M.
c. Compressive Strength: Make at least four compressive strength specimens for each 115 cubic m 150
cubic yards of concrete of each mix in accordance with the following Standards: ASTM C 31/C 31M, ASTM C 192/C 192M
, ASTM C 39/C 39M.
d. Air Content: Perform tests for air content on air-entrained, wet-cast concrete for each 115 cubic
m 150 cu yd of concrete, but not less often than once each day when air-entrained concrete is used.
Determine the air content in accordance with either ASTM C 231 or ASTM C 173/C 173M for normal weight
aggregates and ASTM C 173/C 173M for lightweight aggregates.
e. Unit Weight: Perform tests for unit weight a minimum of once per week to verify the yield of batch
mixes. Perform unit weight tests for each75 cubic m 100 cu yd of lightweight concrete in accordance
with ASTM C 138/C 138M.
Submit test reports as specified in the Submittals paragraph and documentation to demonstrate compliance with
the above subparagraphs.
1.5.2.3 Inspection
The Contracting Officer may place an inspector in the plant when the units covered by this specification are
being manufactured. The burden of payment for plant inspection will be clearly detailed in the specification.
The precast concrete producer shall give notice 14 days prior to the time the units will be available for plant
inspection. Neither the exercise nor waiver of inspection at the plant will affect the Government's right to
enforce contractual provisions after units are transported or erected.
1.6 HANDLING, STORAGE AND DELIVERY
1.6.1 Handling
Handle, transport, and store products in a manner to minimize damage. Lifting devices or holes shall be consistent
with industry standards. Perform lifting with methods or devices intended for this purpose as indicated on shop
drawings.
1.6.2 Storage
Store units off the ground or in a manner that will minimize potential damage.
1.6.3 Delivery
Deliver precast units to the site in accordance with the delivery schedule to avoid excessive build-up of units
in storage at the site. Upon delivery to the jobsite, all precast concrete units will be inspected by the Contracting
Officer for quality and final acceptance.
PART 2 PRODUCTS
2.1 MATERIALS
Except as otherwise specified in the following paragraphs, conform material to Section 03 31 00.00 10 CAST-IN-PLACE
STRUCTURAL CONCRETE and Section 03 20 01.00 10 CONCRETE REINFORCEMENT.
2.1.1 Cement
Furnish cement conforming to ASTM C 150, Type I, II, III or V. Furnish blended cements that conform to ASTM C 595
.
2.1.2 Silica Fume
NOTE: Silica fume concrete should be used where low permeability and enhanced
durability are necessary and justified by additional cost, such as marine structures
or other places where low permeability or severe abrasion resistance is required.
Finishing is more difficult than conventional concrete. Proper curing is essential
because there is a strong tendency for severe plastic shrinkage cracking. Assistance
from a technical representative from the silica fume supplier may be required
during batching, finishing, and curing at start-up of the job, when being used
for the first time by the precast concrete producer. A HRWR recommended by
the manufacturer of the silica fume should be used.
Provide silica fume conforming to ASTM C 1240. Provide available alkalies conforming to the optimal limit given
in Table 2 of ASTM C 1240. Silica fume may be furnished as a dry, densified material or as a slurry. When necessary,
coordinate the services of a technical representative experienced in mixing, proportioning, placement procedures,
and curing of concrete containing silica fume.
2.1.3 Fly Ash and Pozzolans
Fly ash is [required][used] as an admixture conforming to ASTM C 618, Class [C or F] with 4 percent maximum loss
on ignition and 35 percent maximum cement replacement by weight.
2.1.4 Ground Granulated Blast-Furnace Slag
NOTE: Ground granulated blast furnace slag and fly ash are materials listed
in the EPA's Comprehensive Procurement Guidelines (CPG) http://www.epa.gov/cpg).
If the Architect/Engineer determines that use of certain materials meeting the
CPG content standards and guidelines would result in inadequate competition,
do not meet quality/ performance specifications, are available at an unreasonable
price or are not available within a reasonable time frame, the Architect/Engineer
may submit written justification and supporting documentation for not procuring
designated items containing recovered material. Written justification may be
submitted on a Request for Waiver Form to the NASA Environmental Program Manager
for approval. The Request for Waiver Form is located in the NASA Procedures
and Guidelines (NPG 8830.1) (http://nodis3.gsfc.nasa.gov).
Ground granulated blast furnace slag is [required][used] as an admixture conforming to ASTM C 989, Grade [120]
with between 25 to 50 percent maximum cement replacement by weight.
2.1.5 Water
Furnish water potable or free of deleterious substances in amounts harmful to concrete or embedded metals.
2.1.6 Aggregates
2.1.6.1 Selection
NOTE: Select gradation(s) based on job requirements and constraints. The nominal
maximum aggregate size may not exceed one-fifth the narrowest dimension between
sides of forms, nor three-quarters the minimum clear spacing between individual
reinforcing bars or wires.
Furnish aggregates conforming to ASTM C 33. Provide aggregates not containing any substance, which may be deleteriously
reactive with the alkalies in the cement.
2.1.6.2 Aggregates for Lightweight Concrete
ASTM C 330
2.1.7 Admixtures
2.1.7.1 Air-Entraining
NOTE: Air-entraining requirements may be deleted when the project is located
in a nonfreezing climate.
ASTM C 260
2.1.7.2 Accelerating, Retarding, Water Reducing [Moderate to High]
ASTM C 494/C 494M
2.1.7.3 Pigments
Non-fading and lime-resistant
2.1.8 Reinforcement
2.1.8.1 Reinforcing Bars
NOTE: Specify ASTM A 706/A 706M reinforcing where welding or bending of reinforcement
bars is important. In addition, ASTM A 775/A 775M epoxy coated reinforcing
may be specified where extra reinforcement corrosion protection is required.
a. Deformed Billet-steel: ASTM A 615/A 615M
b. Deformed Low-alloy steel: ASTM A 706/A 706M
2.1.8.2 Reinforcing Wire
a. Plain Wire: ASTM A 82/A 82M
b. Deformed Wire: ASTM A 496/A 496M
2.1.8.3 Welded Wire Fabric
a. Plain Wire: ASTM A 185/A 185M
b. Deformed Wire: ASTM A 497/A 497M
2.1.8.4 Epoxy Coated Reinforcement
a. Reinforcing Bars: ASTM A 775/A 775M
b. Wires and Fabric: ASTM A 884/A 884M
2.1.8.5 Galvanized Reinforcement
Provide galvanized reinforcement conforming to ASTM A 767/A 767M.
2.1.9 Synthetic Fiber Reinforcement
Synthetic fiber shall be polypropylene with a denier less than 100 and a nominal fiber length of 50 mm 2 inch
.
2.1.10 Inserts and Embedded Metal
All items embedded in concrete shall be of the type required for the intended task, and meet the following standards.
a. Structural Steel Plates, Angles, etc.: ASTM A 36/A 36M
b. Hot-dipped Galvanized: ASTM A 153/A 153M
c. Proprietary Items: In accordance with manufacturers published literature
2.1.11 Accessories
a. Rubber Gaskets for Circular Concrete Sewer Pipe and Culvert Pipe: ASTM C 443M ASTM C 443.
b. External Sealing Bands for Noncircular Sewer, Storm Drain and Culvert Pipe: ASTM C 877M ASTM C 877
.
c. Preformed Flexible Joint Sealants for Concrete Pipe, Manholes, and Manufactured Box Sections: ASTM C 990M
ASTM C 990.
d. Elastomeric Joint Sealants: ASTM C 920
2.1.12 Pipe Entry Connectors
Pipe entry connectors shall conform to ASTM C 923M ASTM C 923 or ASTM C 1478M ASTM C 1478.
2.1.13 Grout
NOTE: Delete air-entraining requirements when the project is located in a nonfreezing
climate.
Nonshrink Grout shall conform to ASTM C 1107/C 1107M. Cementitious grout shall be a mixture of portland cement,
sand, and water. Proportion one part cement to approximately 2.5 parts sand, with the amount of water based
on placement method. [Provide air entrainment for grout exposed to the weather.]
PART 3 EXECUTION
3.1 FABRICATION AND PLACEMENT
Perform fabrication in accordance with NPCA QC Manual and/or ACPA QPC unless specified otherwise.
3.1.1 Forms
Use forms, for manufacturing precast concrete products, of the type and design consistent with industry standards
and practices. They should be capable of consistently providing uniform products and dimensions. Construct
forms so that the forces and vibrations to which the forms will be subjected can cause no product damage. Clean
forms of concrete build-up after each use. Apply form release agents according to the manufacturers recommendations
and do not allow to build up on the form casting surfaces.
3.1.2 Reinforcement
Follow applicable ASTM Standard or ACI 318MACI 318 for placement and splicing. Fabricate cages of reinforcement
either by tying the bars, wires or welded wire fabric into rigid assemblies or by welding, where permissible,
in accordance with AWS D1.4/D1.4M. Position reinforcing as specified by the design and so that the concrete
cover conforms to requirements. The tolerance on concrete cover shall be one-third of that specified but not
more than 13 mm 1/2 inch. Provide concrete cover not less than 13 mm 1/2 inch. Take positive means to assure
that the reinforcement does not move significantly during the casting operations.
3.1.3 Embedded Items
Position embedded items at locations specified in the design documents. Perform welding in accordance with AWS D1.1/D1.1M
when necessary. Hold rigidly in place inserts, plates, weldments, lifting devices and other items to be imbedded
in precast concrete products so that they do not move significantly during casting operations.
3.1.4 Synthetic Fiber Reinforced Concrete
NOTE: Synthetic fiber reinforcement may be used in concrete as an aid in preventing
plastic or shrinkage cracking in placements susceptible to this condition.
Fiber reinforcement will not be used as a substitute for wire mesh and where
service temperature may exceed 150 degrees C (300 degrees F). Concentrations
above 0.1 percent by volume are not cost-effective.
Add fiber reinforcement to the concrete mix in accordance with the applicable sections of ASTM C 1116/C 1116M
and the recommendations of the manufacturer, and in an amount of [0.1] [_____] percent by volume.
3.2 CONCRETE
3.2.1 Concrete Mixing
Mixing operations shall produce batch-to-batch uniformity of
strength, consistency, and appearance.
3.2.2 Concrete Placing
Deposit concrete into forms as near to its final location as practical. Keep the free fall of the concrete to
a minimum. Consolidate concrete in such a manner that segregation of the concrete is minimized and honeycombed
areas are kept to a minimum. Use vibrators to consolidate concrete with frequencies and amplitudes sufficient
to produce well consolidated concrete.
3.2.2.1 Cold Weather Concreting
Perform cold weather concreting in accordance with ACI 306.1.
a. Provide adequate equipment for heating concrete materials and protecting concrete during freezing
or near-freezing weather.
b. Free from frost all concrete materials and all reinforcement, forms, fillers, and ground with which
concrete is to come in contact.
c. Do not use frozen materials or materials containing ice.
d. In cold weather the temperature of concrete at the time of placing shall not be below8 degrees C
45 degrees F. Discard concrete that freezes before its compressive strength reaches 3.45 MPa 500 psi
.
3.2.2.2 Hot Weather Concreting
Recommendations for hot weather concreting are given in detail in ACI 305R. During hot weather, give proper
attention to constituents, production methods, handling, placing, protection, and curing to prevent excessive
concrete temperatures or water evaporation that could impair required strength or serviceability of the member
or structure. The temperature of concrete at the time of placing shall not exceed 32 degrees C 90 degrees F.
3.2.3 Concrete Curing
NOTE: Due to the immediacy of form removal, dry-cast products have a tendency
to undergo undesirable accelerated drying. Consequently, early curing periods
are most critical to ensure protection from extreme temperatures and dryness.
Dry-cast products must be protected from drafts to prevent cracking.
Commence curing immediately following the initial set and completion of surface finishing.
3.2.3.1 Curing by Moisture Retention
Prevent moisture evaporation from exposed surfaces until adequate strength for stripping is reached by one of
the following methods:
a. Cover with polyethylene sheets a minimum of 0.15 mm 6 mils thick in accordance with ASTM C 171.
b. Cover with burlap or other absorptive material and keep continually moist.
c. Use of a membrane-curing compound applied at a rate not to exceed 19 square m/4L 200 square ft/gallon
, or in accordance with manufacturers' recommendations according to ASTM C 309.
3.2.3.2 Curing with Heat and Moisture
NOTE: Cure as above surfaces that will be exposed to weather during service,
a minimum of 3 days. Forms should be considered effective in preventing evaporation
from the contact surfaces. If air temperature is below 50°F the curing period
must be extended.
Do not subject concrete to steam or hot air until after the concrete has attained its initial set. Apply steam,
if used, within a suitable enclosure, which permits free circulation of the steam in accordance with CAN/CSA A23.4
. If hot air is used for curing, take precautions to prevent moisture loss from the concrete. The temperature
of the concrete shall not be permitted to exceed 65 degrees C 150 degrees F. These requirements do not apply
to products cured with steam under pressure in an autoclave.
3.2.4 Surface Finish
Finish unformed surfaces of wet-cast precast concrete products as specified. If no finishing procedure is specified,
finish such surfaces using a strike-off to level the concrete with the top of the form.
3.2.4.1 Formed Non-Architectural Surfaces
Cast surfaces against approved forms following industry practices in cleaning forms, designing concrete mixes,
placing and curing concrete. Normal color variations, form joint marks, small surface holes caused by air bubbles,
and minor chips and spalls will be accepted but no major imperfections, honeycombs or other major defects will
be permitted.
3.2.4.2 Unformed Surfaces
Finish unformed surfaces with a vibrating screed, or by hand with a float. Normal color variations, minor indentations,
minor chips and spalls will be accepted but no major imperfections, honeycombs, or other major defects shall
be permitted.
3.2.4.3 Special Finishes
Troweled, broom or other finishes shall be according to the requirements of project documents and performed in
accordance with industry standards or supplier specifications. Submit finishes for approval when required by
the project documents. The sample finishes shall be approved prior to the start of production.
3.2.5 Stripping Products from Forms
Do not remove products from the forms until the concrete reaches the compressive strength for stripping required
by the design. If no such requirement exists, products may be removed from the forms after the final set of
concrete provided that stripping damage is minimal.
3.2.6 Patching and Repair
No repair is required to formed surfaces that are relatively free of air voids and honeycombed areas, unless
the surfaces are required by the design to be finished.
3.2.6.1 Repairing Minor Defects
Defects that will not impair the functional use or expected life of a precast concrete product may be repaired
by any method that does not impair the product.
3.2.6.2 Repairing Honeycombed Areas
When honeycombed areas are to be repaired, remove all loose material and cut back the areas into essentially
horizontal or vertical planes to a depth at which coarse aggregate particles break under chipping rather than
being dislodged. Use proprietary repair materials in accordance with the manufacturer's instructions. If a
proprietary repair material is not used, saturate the area with water. Immediately prior to repair, the area
should be damp, but free of excess water. Apply a cement-sand grout or an approved bonding agent to the chipped
surfaces, followed immediately by consolidating an appropriate repair material into the cavity.
3.2.6.3 Repairing Major Defects
Evaluate, by qualified personnel, defects in precast concrete products which impair the functional use or the
expected life of products to determine if repairs are feasible and, if so, to establish the repair procedure.
3.2.7 Shipping Products
Do not ship products until they are at least 5 days old, unless it can be shown that the concrete strength has
reached at least 75% of the specified 28-day strength, or that damage will not result, impairing the performance
of the product.
3.3 INSTALLATION
3.3.1 Site Access
It is the Contractor's responsibility to provide adequate access to the site to facilitate hauling, storage and
proper handling of the precast concrete products.
3.3.2 General Requirements
a. Install precast concrete products to the lines and grades shown in the contract documents or otherwise
specified.
b. Lift products by suitable lifting devices at points provided by the precast concrete producer.
c. Install products in accordance with the precast concrete producer's instructions. In the absence
of such instructions, install underground utility structures in accordance with ASTM C 891. Install
pipe and manhole sections in accordance with the procedures outlined by the American Concrete Pipe Association.
d. Field modifications to the product will relieve the precast producer of liability even if such modifications
result in the failure of the product.
3.3.3 Water Tightness
Where water tightness is a necessary performance characteristic of the precast concrete product's end use, watertight
joints, connectors and inserts should be used to ensure the integrity of the entire system.
3.4 FIELD QUALITY CONTROL
NOTE: Manholes should be tested prior to backfilling to verify the integrity
of the installed product. Testing prior to backfilling facilitates quick and
easy repair when required. When vacuum testing a backfilled manhole, appropriate
adjustments must be made to the testing procedure to account for site conditions
such as high water tables as to avoid over loading boots and connectors. Prior
to vacuum testing, make calculations to ensure that connectors and boots are
not loaded past the design limit as indicated in ASTM C 923.
3.4.1 Site Tests
When water tightness testing is required for an underground product, use one of the following methods:
3.4.2 Vacuum Testing
Prior to backfill vacuum test system according to ASTM C 1244M ASTM C 1244.
3.4.3 Water Testing
Perform water testing according to the contract documents and precast concrete producer's recommendations.