Construction Specification Guideline for
Concrete Streets and Local Roads
agencies are using or developing specifications encompassing quality assurance/quality control (QA/QC) concepts. These concepts are not currently in wide use in
the engineering of local road and streets. While, it is not
clear whether QA/QC concepts are beneficial or costeffective for smaller projects, in time they are likely to be
used for larger local road and street projects. QA/QC
specifications are a combination of end-result specifications and materials and methods specifications. These
statistical specfications use
methods such as random
sampling and lot-by-lot testing. The contractor is responsible for quality control (process control), and the owner/
engineer is responsible for
acceptance of the product.
In this specification, the
acceptance passage requires the contractor to
submit a strength evaluation
plan to the engineer. The testing for both assurance and
acceptance are performed
by a certified agent of the
contractor. Some QA/QC
specifications require the
engineer and the contractor
to run tests separately; the
engineer takes random tests to validate the contractor's
on-going testing procedures. This method requires more
tests and personnel, which could be difficult for some
local public works agencies. By requiring the contractor
to employ certified testing firms, this specification
reduces the burden on the public works agency.
The agency can rely on the contractor's tests without
committing personnel to the project testing.
This document provides guideline specifications useful
for developing concrete pavement project specifications for local roads and streets. These guidelines should
not be used as a specification reference in contract
documents. A contracting agency must modify these
guidelines for local conditions, preferences and construction practices. A contracting agency also must
choose amongst the available material standards and
test methods provided in these guidelines.
This document references
appropriate material standards, test methods and
specifications of American
Association of State Highway
and Transportation Officials
(AASHTO), the American Society of Testing Materials
(ASTM), and Canadian Standards Association (CSA).
These references assume
that the Contractor and the
Engineer will use the applicable standards or methods
that are in effect when bids
are solicited for the project. It
also assumes that the specification writer will choose the
standard or test most suitable for their agency/project.
Footnotes, pictures and diagrams accompany some
specification requirements. These added details provide specific guidance, list important references, and
describe specification features and choices for clarity to
the specification writer.
The acceptance criteria for strength are based upon
quality assurance methods for testing and accepting
pavement concrete that are not normally used for streets
and local roads. Presently, many highway and airport
1
Definitions and Assumptions
Approval: Written authorization or acceptance from the Engineer prior to commencing an activity.
Construction Stakes, Lines, and Grades: The Engineer positions construction stakes to establish lines and
grades for street work and for structures. The engineer stakes the centerline and furnishes bench marks
necessary to correctly lay out the pavement. The contractor maintains these lines, grades, and bench marks
and uses them to lay out the work under the contract. The contractor must carefully preserve stakes and
bench marks.
Contractor, The: The contracted construction firm or its subcontractor hired to perform all or part of the
work under the contract specifications and drawings.
Design Strength: The concrete strength used by the designer in the thickness design method or software to
determine the Plan thickness.
Engineer, The: The owner or an agent of the owner, that issues drawings and specifications, or administers
the work under contract specifications and drawings, or both.
Intent of the Contract: For the contractor to build the pavement in accordance with the specification and in
reasonably close conformity with the lines, grades, thickness, and typical cross sections shown in the
project plans or as established by the engineer/owner. Construction methods are generally left to the
discretion of the contractor, as long as progress and workmanship are satisfactory.
Lot: Term used for strength acceptance testing, representing the concrete pavement placed in one day, or
with one construction method (i.e. slipform vs. fixed form), or with one unique concrete mixture (i.e. standard
vs. accelerated-strength).
Pavement Placement Unit: The concrete pavement placed in one day, or with one construction method
(i.e. slipform vs. fixed form), or with one unique concrete mixture (i.e. standard vs. accelerated-strength).
Alternately called a lot for strength acceptance testing.
Pay Strength: The mean (average) strength of all sublot test results minus one standard deviation of the
sublot test results.
Plan Thickness: The nominal concrete slab thickness shown in the Plans.
Sublot: The volume, area or lineal quantity requiring a sample test(s) for acceptance.
Supplementary Cementitious Materials: Substances that alone have hydraulic cementing properties (set
and harden in the presence of water), such as natural pozzolans, fly ash or ground-granulated blast furnace
slag.
Testing Laboratory: An organization that measures, examines, performs tests, or otherwise determines the
characteristics or performance of materials or products. This may include organizations that offer commercial testing services, an in-house quality control function, or other organizations providing the required
testing services. These firms must meet requirements of ASTM C 1077, "Standard Practice for Laboratories
Testing Concrete and Concrete Aggregates for Use in Construction and Criteria for Laboratory Evaluation."
Testing Technician: Person or persons that are either engineers, engineering technicians, or experienced
craftsman with qualifications in the appropriate field equivalent to ACI (American Concrete Institute) Level I
Technician, or NICET (National Institute for Certification in Engineering Technologies) Level II.
The Plans: The drawings, diagrams, details or standards describing the dimension, elevation, form, location
or size of the pavement or any of its components, including the foundation and any existing infrastructure.
2
Description
501.01 This work consists of constructing portland cement concrete pavement on a prepared surface*.
Material
501.02 Furnish materials conforming to the latest version of the standard specifications in Table 501-1, as
appropriate. Furnish materials only from sources approved by the Engineer. Do not use different brands or
types of portland cement, or the same brand or type of portland cement from different mills without approval.
Table 501-1
* Note to specification writer- For recommendations and specification language regarding preparation of natural
subgrade, stabilized soil, aggregate subbase, asphalt subbase and/or lean concrete subbase consult appropriate passages
in Section 300 of the AASHTO "Guide Specifications for Highway Construction" (see Reference 1) or your state's Standard
Specifications. Specify a trimming tolerance for the prepared subbase surface of ±6 mm (±0.25 in.) from the staked line and
grade elevation.
3
Equipment
501.03 Furnish equipment conforming to the following:
1.
Batching Plant and Equipment. Use a batching plant conforming to AASHTO M 157, ASTM C 94 or CSA
A23.1. The scales for weighing aggregates and cement must meet the requirements of AASHTO M 157,
ASTM C 94 or CSA A23.1, and subsection 109.01 of the AASHTO "Guide Specifications for Highway
Construction."(1)
2.
Mixers. Mix the concrete in a central-mix plant or in truck mixers conforming to AASHTO M 157, ASTM
C 94 or CSA A23.1. Operate all equipment within the manufacturer's recommended capacity to produce
concrete of uniform consistency.
A) Central-mix Plant. Combine aggregates, cement, admixtures and water in the mixer. Dispense liquid
admixtures through controlled flow-meters or use dispensers with sufficient capacity to measure, at
one time, the full quantity of each admixture required for a batch. If the mixture requires more than
one admixture, dispense each with separate equipment.
B) Truck Mixers and Truck Agitators. Use truck mixers for mixing and hauling concrete and truck
agitators for hauling central-mixed concrete that meet the requirements of AASHTO M 157, ASTM
C 94 or CSA A23.1. Do not use truck mixers with blade wear more than 25 mm (1 in.) from the
manufactured dimension, or with accumulations of hard concrete or mortar on the inside of the drum.
C) Non-Agitator Trucks. Use non-agitator trucks for hauling central-mixed concrete that meet the
requirements of AASHTO M 157, ASTM C 94 or CSA A23.1.
3.
Paving Equipment. Furnish the paving and finishing equipment applicable to the type of construction
in this contract, as follows:
A) Slipform machines. If slipforming, furnish machines capable of spreading, consolidating, screeding,
and finishing the freshly placed concrete in one pass to provide a dense and homogeneous
pavement requiring minimal hand finishing.
Equip the paving machine with the following:
1) Automatic controls to control line and
grade from either or both sides of the
machine, or from averaging-skis that
reference the grade.
2) Vibrators to consolidate the concrete
for the full width and depth of the strip
of pavement being placed.
3) A positive interlock system to stop all
vibration and tamping elements when
forward motion of the machine stops.
B)
Self-Propelled Form-Riding Machines.
Where used, furnish mechanical, self-propelled spreading and finishing machines
capable of consolidating and finishing the
concrete with minimal hand finishing. Do
not use machines that displace the fixed
side forms.
Furnish internal immersed tube or multiple
spud vibrators. Attach vibrators to the
spreader or finishing machine, or attach
them on a separate carriage that precedes
the finishing machine.
4
C) Manual Fixed-Form Paving Machines. Where needed,
furnish spreading and finishing machines capable of consolidating and finishing concrete up to 200 mm (8 in.) thick.
D) Vibrators. Furnish internal immersed tube or multiple
spud vibrators for all paving more than 200 mm (8 in.)
thick. Operate the vibrators at frequencies within 50008000 vibrations/minute.
Furnish a surface pan vibrator as an alternate to immersed tube or multiple spud vibrators for consolidation
of 200-mm (8-in.) or thinner concrete slabs. Operate the
surface pan vibrator at a frequency no less than 3500
vibrations/minute.
For construction of irregular areas, use handheld vibrators. Operate the vibrator at a frequency in the range
recommended by the manufacturer for the vibrator's
head diameter.
4. Concrete Saws†. Furnish concrete saws that
are capable of sawing new concrete for crack
control on all concrete pavement in this contract. Equip all saws with blade guards and
guides or devices to control alignment and
depth.
5.
Forms. Furnish straight, steel forms with a
height equal to the nominal pavement thickness at the edge. For curved edges with radii
less than 30 m (100 ft), furnish flexible or
curved forms. Conform to the following:
A) Use straight forms that are 3 m (10 ft)
minimum in length.
B) Use forms with a maximum top face deviation of 3 mm in 3 m (1/8 in. in 10 ft).
C) Use forms with a maximum inside face
deviation of 6 mm in 3 m (1/4 in. in 10 ft)
D) Equip each form with devices to adequately secure the form to the subbase
or subgrade, and to withstand operation
of the paving equipment and pressure of
the concrete.
E) Equip each form with devices to tightly
join and lock each end to abutting form
sections.
6. Joint Sealing. Furnish joint sealing equipment, if required, according to the sealant manufacturer's recommendations for the sealant specified
in the Plans.
7.
Finishing tools. Furnish aluminum, magnesium or wooden hand finishing tools.
†
Note to specification writer - It is advisable not to specify a specific type or style of saw for your project and to allow the
contractor to choose the saws depending upon previous experiences. Providing the contractor this freedom ensures the
highest degree of success in jointing the pavement.
It is often necessary for the contractor to saw at night to prevent random cracking. The noise generated from sawing
operations may exceed that allowable by local municipal noise-ordinances. Experienced agencies and contractors meet
with law-enforcement agencies before starting a project to explain the necessity of night sawing and to receive special
permission to violate a noise ordinance. To avoid late-night sawing a contractor may also choose to use an early-entry dry
saw that permits joint sawing sooner than a wet-diamond saw. Early-entry dry saws are also much quiter.
5
Construction Requirements
501.04 Composition of Concrete Mixture (Proportioning). Proportion and produce concrete that conforms to
Table 501-2 and 501-3 for the types specified, including footnotes. Use supplementary cementitious
materials and chemical admixtures to alter fresh and hardened properties as needed. Begin producing the
mixture(s) only after receiving approval notification from the Engineer‡.
Table 501-2
(1) Verify the mixture durability as outlined in ACPA guide specification IS415T (see Reference 2).
For calculating the water/cementitious ratio, add the mass of the supplementary cementitious material
(2) to the mass of portland cement to determine total cementitious content.
For gravel and stone coarse aggregate determine air content using AASHTO T 152, ASTM C 231, or
(3) CSA A23.2.19. For mixtures containing slag or highly porous coarse aggregate use AASHTO T 196,
ASTM C 173 or CSA A23.2.15.
(4) Maintain the minimum cementitious content in mixtures (portland cement and supplementary
cementitious materials). When proportioning a mixture containing fly ash, add the fly ash at 10 to 25%
by weight of portland cement. Select fly ash quantity to produce acceptable workability, but avoid the
pessimism quantity to ensure long-term durability (see Reference 3).
(5) Determine slump using AASHTO T 119, ASTM C 143, or CSA A23.2.20. Measure the slump 4 to 5
minutes after the concrete is discharged from the mixer.
(6) Prepare, cure and test strength test specimens using AASHTO T 23, ASTM C 31 or CSA A23.2-3C.
(7) Design fast-track mixtures for an early strength appropriate for opening the project to traffic and
consistent with Table 501-11. (Typical fast-track specifications for streets and local roads require 24
MPa (3500 psi) in 24 hours.)
Table 501-3
‡
Note to specification writer - If historical performance records for concrete mixtures are not adequate or available, it is
necessary to add the following additional requirement under section 501.04: Prepare a test mixture (or mixtures) from the
same material source(s) proposed for use, and test it (them) to demonstrate its (their) adequacy for the project. Secure the
services of a certified laboratory for this testing in accordance with section 501.15. Provide all of the information outlined in
Table A-1 for each concrete mixture proposed for use on the project. Submit written documentation describing the concrete
mixture to the Engineer at least 30 days before production. (See page 23 for Table A-1).
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501.05 Producing Concrete. Conform to applicable sections of AASHTO M 157, ASTM C 94 or CSA A23.1, and the
following requirements for storing and handling material, and for batching, mixing and delivering concrete.
1. Storing and Handling Material. Store and handle all material in a manner that prevents segregation,
contamination, or other harmful effects. Do not use any material that has been stored for a period
exceeding the manufacturer's recommended shelf life. Do not use cement or fly ash containing evidence
of moisture contamination. Store and handle aggregate in a manner that ensures reasonably uniform
moisture content at the time of batching. Where recommended by the manufacturer, agitate chemical
admixtures to ensure consistency during batching.
2.
Batching Concrete. Batch the concrete following to the approved mixture proportions and within the
tolerances in Table 501-4.
Table 501-4
3. Mixing Concrete. Produce the mixture(s)
according to the approved proportions
except as necessary for the following
conditions:
A) For air-entrained concrete, adjust proportions or mixing procedures appropriately to maintain the air content of the
concrete within the specified zone.
B) If concrete of the desired plasticity and workability cannot be produced, change the mixture
proportions as necessary without adjusting the design cement content, except as provided in 3C
and 3D below.
C) If concrete having the required consistency cannot be produced without adding water to the mixture,
increase the quantity of cementitious materials at an equal weight to the quantity of extra water
necessary. Always remain below the maximum allowable water-cementitiuous ratio.
D) If a new mixture is necessary or desired, submit a revised mixture design for approval before making
any changes in the supply sources or character of the materials. Do not use unapproved concrete
mixtures.
In a central mixer, mix each batch for the minimum time recommended by the plant's manufacture§.
Begin counting the mixing time after all cement and aggregate enters the drum. End the mixing time when
the discharge chute opens. Transfer time in multiple-drum mixers is included in the mixing time. Remove
the contents of an individual drum before a succeeding batch is charged into the drum. Discharge the
concrete mixture without segregation.
In a truck mixer, charge the batch into the
drum so a portion of the mixing water enters
in advance of the cement. Mix each batch of
concrete not less than 70 nor more than 100
revolutions of the drum or blades at mixing
speed. Begin the count of mixing revolutions as soon as all material, including water, is in the mixer drum.
4. Delivering Concrete. Deliver concrete with
agitating or non-agitating trucks. Coordinate
delivery to permit continuous placing, with
no concrete achieving initial set before placing adjacent concrete. Minimize rehandling
of the concrete. Conform to Table 501-5.
§
Note to specification writer - Mixing time requirements vary depending upon batch plant mixer design and era of manufacturing. Consult the plant manufacturer to verify the time appropriate for the plant provided by the contractor or set the
mixing time requirement based on a performance test (see ASTM C 94) performed by the contractor before the project is fully
underway. In lieu of a manufacturer's specific recommendation or a performance test, specify a minimum time of 60 seconds.
7
Table 501-5
(1) ASTM C150, C595 and C1157 cement types listed here. Substitute AASHTO or CSA designations as
appropriate.
(2) For delivery in truck mixers, additional water and admixtures (if in the approved mixture) may be
added to obtain the required slump or air content at the paving site, providing the total of all water in
the mixture is less than the maximum required by the water/cementitiuous ratio. Remix concrete within
45 minutes (75 minutes for Type I, IA, II, IIA or GU cements with water reducing/retarding admixture)
after the initial introduction of mixing water to cement or cement to aggregates. Do not add additional
water and admixtures if the concrete has obtained initial set.
501.06 Paving. Uniformly dampen the prepared roadbed surface before paving. Do not place concrete on
frozen subgrade or subbase. If operating vehicles on subbase or subgrade before or while paving, repair
excessive rutting or other damages before placing concrete at the direction of the Engineer.
Place concrete with fixed-form or slipform paving equipment. Operate the paving equipment with a
continuous forward movement, as practicable, and coordinate mixing, delivering, and spreading concrete
to provide uniform progress. Except in an emergency, apply no tractive force to a slipform-paving machine,
except that which is controlled from the machine.
Place reinforcing steel as shown in the plans. Either firmly position the reinforcement on acceptable supports
before placing the concrete or mechanically insert the reinforcement into the plastic concrete to the required
location and alignment tolerances.
In irregular areas or areas inaccessible to self-propelled paving equipment, construct the pavement using
fixed forms and manual fixed-form paving equipment. Thoroughly and uniformly vibrate and consolidate the
concrete during placement without segregating the material. Use handheld internal vibrators along forms
and around embedded objects, including dowel baskets and utility fixtures, where necessary to ensure
adequate consolidation.
When paving in extremely cool or warm air temperatures, use adequate concrete protection measures.**
Concrete that the Engineer suspects was damaged by frost action or excessive heat is subject to additional
testing to determine its quality.
501.07 Joints††. Construct transverse and longitudinal joints, by forming or sawing, to the details, dimensions and
spacing shown on the Plans, using approved equipment. Use construction-style joints at any longitudinal
joint necessary to facilitate construction staging.
Extend all transverse joints the entire width of paving. When constructing curbs or medians integral with the
pavement, construct transverse joints continuous through the curb or median. When the pavement abuts an
existing pavement or curb and gutter, construct transverse joints in the pavement at locations matching
transverse joints or cracks in the existing pavement, or use an isolation joint to separate the new pavement
from the old.
** Note to specification writer - You may reference your state's cold-weather and hot-weather requirements, or reference
ACI 306R and ACI 305R respectively to define the minimally acceptable practice for protection in your area. We specify no
air or concrete temperature limitations in this guideline, assuming that adequate protection will control potential problems.
††
Note to specification writer - It is advisable to review and revise your standard joint details to conform to the nomenclature, and principles outlined by this specification. Page 21 and 22 provide details for transverse and longitudinal joints, and
for boxing out utility fixtures within the pavement.
8
1. Contraction joints. Construct by forming or sawing‡‡ to control cracking. When forming joints, install a
parting strip that remains in place or depress a forming tool into the concrete.
When sawing joints, begin as soon as the concrete hardens sufficiently to prevent excessive raveling
along the saw cut and finish before conditions induce uncontrolled cracking, regardless of the time or
weather. Saw longitudinal contraction joints immediately after sawing transverse joints. Do not stop
sawing, except as follows: (1) Do not saw a joint at or near any location where a shrinkage crack is visible;
(2) Do not continue to saw a joint if a crack forms ahead of the saw cut while sawing.
If uncontrolled cracking occurs, follow requirements of Section 501.20.
2.
Construction joints. Construct a transverse construction joint at the end of each day's work or where
concrete placement is interrupted long enough that the concrete begins to harden. Use a metal or
wooden bulkhead to form the joint, or saw completely through the concrete and remove excess material
to expose solid concrete. Metal or wooden bulkhead forms must match the pavement cross-section and
permit the installation of dowel bars. Construct longitudinal construction joints where needed, conforming to the details shown on the Plans.
3.
Isolation joints. Construct transverse and longitudinal isolation joints by sawing or by installing a preformed
joint filler in the concrete. Install the preformed joint filler full-depth, perpendicular to the subgrade, and
conform to the details shown on the Plans. Remove all concrete that leaks into the joint closure space.
Construct longitudinal isolation joints where needed, conforming to the details shown on the Plans.
4.
Dowel bars, Tie bars, Hookbolts, Reinforcing Steel or Mesh. Where required, place dowel bars,
tiebars, hook bolts and reinforcing steel, as follows:
A) Dowel bars for contraction joints. Place dowel bars at the location, depth and spacing shown in the
plans. Fasten the dowels to rigid baskets or insert them while the concrete is plastic. Align dowels
vertically and horizontally within 3.0% of true alignment in all directions, and provide a minimum
embedment length of 150 mm (6.0 in.) on either side of the joint. Fasten dowel baskets securely to
the subbase or subgrade using stakes or nails. Use dowels with a factory-applied debonding agent
or coat each bar with form-release oil before paving.
B) Dowel bars for construction joints. Place dowel bars in transverse construction joints at the location,
depth and spacing shown on the Plans. Drill holes and epoxy dowels into position in a sawed joint
face, or insert them through holes in a bulkhead form taking care to maintain proper alignment.
Dowels must meet the tolerance specified in 501.07.4(A).
C) Dowel bars for isolation joints. Place dowel bars in transverse isolation joints at the location, depth
and spacing shown on the plans. Fasten the dowels to an expansion basket that remains in the
pavement, provides joint closure space and holds each dowel parallel to the surface and center line
of the slab. Dowels must meet the tolerance specified in 501.07.4(A). Attach expansion caps to each
dowel bar as shown on the Plans.
D) Tie bars. Place tie bars reasonably perpendicular to the longitudinal joints with mechanical insertion
equipment or rigidly secured chairs without damaging or disrupting the concrete. Do not bend and
straighten tie bars into correct position by more than 90°. Repair or replace broken or badly damaged
tie bars.
E) Threaded hook bolts. As an option, use threaded hook bolts instead of tie bars. Fasten hook bolts
to the fixed forms securely.
F) Reinforcing Steel or Mesh reinforcement. Place deformed reinforcing steel, or mesh reinforcement
at the location and orientation shown on the Plans. If required, use plastic or metal chairs to support
reinforcement, conforming to the Plans.
‡‡
Note to specification writer - Avoid specification language dictating the methodology or specific timing for joint sawing or
forming. The purpose of this passage is to define the expected result, while giving just enough guidance to define appropriate practice. Direct specific sawing methodology decisions and the accompanying responsibility for crack control to the
contractor. If uncontrolled cracking occurs, the contractor's crew will determine whether to start sawing sooner, skip joints,
use early-entry dry sawing or increase the number of saws. As a rule, some raveling of green concrete is expected in order
for sawing to prevent uncontrolled cracking. It is also acceptable practice when using conventional saws to saw every third
transverse contraction joint and then return to saw the intermediate joints as soon as possible.
9
501.08 Surface Finishing. Hand-float the surface only as needed to produce a uniform surface, and sharp corners;
do not use excess mortar to build up slab edges or round the slab corners. Before the concrete's initial set,
work the pavement edges along each side of transverse isolation joints, formed joints, transverse
construction joints, and fixed forms to produce a 6-mm (1/4-in.) continuous radius and a smooth, dense
mortar finish. As needed, check the surface of the fresh concrete with a long-handled straightedge that is
3 m (10 ft) or longer. Remove high areas indicated by the straightedge. Overlap each successive pass of
the straightedge by about 1.5 m (5 ft).
Protect the surface from rain damage.§§
501.09 Texturing. After surface finishing, texture all concrete surfaces that will be used by traffic. Use either handoperated or mechanical tools to produce a uniform texture that conforms to the dimensions shown on the
Plans and the following:
1. Design Speed less than 80 km/h (50 mph). Apply a burlap-drag, turf-drag or broom texture.
For a burlap-drag texture, drag two layers of moistened burlap along the pavement in the direction of
paving. The burlap must be sufficiently long and wide enough to cover the entire pavement width and
produce a uniform texture with corrugations about 1.5 mm (1/16 in.) deep. Clean the burlap periodically
to remove encrusted mortar or replace with new burlap.
For a turf-drag texture, drag plastic turf along the pavement in the direction of paving. The plastic turf must
be sufficiently long and wide enough to cover the entire pavement width and produce a uniform texture
with corrugations about 1.5 mm (1/16 in.) deep. Use turf with a blade density of 77500 blades/m2 (7200
blades/ft2) and each blade at least 20 mm (0.75 in.) long.
For a broom texture, use a stiff-bristled broom, drawing it from the pavement center to the edges. Overlap
strokes slightly to produce a uniform texture with corrugations about 1.5 mm (1/16 in.) deep.
2.
Design Speed greater than 80 km/h (50 mph). Apply a longitudinal or transverse texture*** in
conformance with the plans.
501.10 Curing. After texturing, and immediately after bleed water leaves the surface, coat the surface of the
slab, and for slipform construction the sides of the slab, with approved curing compound. For fixed-form
work, coat the sides of the pavement after removing forms. Conform to these additional requirements:
1. Apply the compound at a rate of 5.0 m2/L (200 ft2/gal) for standard mixtures and applications. Use
an application rate of 3.75 m2/L (150 ft2/gal) for fast-track concrete, and an application rate of 2.5 m2/L
(100 ft2/gal) for slabs thinner than 125 mm (5.0 in.).
2. Omit the application of curing compound when choosing an alternate curing method: water spray or fog,
wet burlap sheets, or plastic sheets. Demonstrate the alternate curing method and receive the engineer's
approval before substituting for curing compound.
3.
For sheet curing materials, extend the sheets beyond the edges of the slab to a distance at least twice
the thickness of the pavement. Place and maintain the sheets in complete contact with the surface.
§§
For more information see reference 4.
*** Note to specification writer - Either transverse or longitudinal tine textures can provide adequate skid resistance and
low-noise qualities (for more information see reference 5).
For transverse tine textures include this requirement in the specification or by note on the plans: Space transverse tines
randomly as follows: minimum spacing 10 mm (1/2 in.), maximum spacing 40 mm (1-1/2 in.), with no more than 50% of the
tines apart by more than 25 mm (1 in.). Use tines that are 3 mm (1/8 in.) wide, with a tolerance of ±0.5 mm (±3/16 in.) and
apply them to a depth of 3-6 mm (1/8-1/4 in.).
For longitudinal tine textures include this requirement in the specification or by note on the plans: Apply a longitudinal tine
texture parallel to the pavement centerline. Space tines uniformly at 20 mm (3/4 in.). Use tines that are 3 mm (1/8 in.) wide
and apply them to a depth of 3-6 mm (1/8-1/4 in.).
10
4.
In cool temperatures, apply insulating blankets to enhance heat containment for areas requiring early
opening to traffic. Use blankets with a layer of closed-cell polystyrene foam and a protective layer of
plastic film providing a minimum thermal resistance (R) rating of 0.035 m≤∞K/W (0.5 hrft≤∞F/BTU).
Conform to the requirements in Table 501-6.
501.11 Sealing Joints.
Where required,
seal joints conforming to the details shown on the
Plans and the
manufacturer's
recommendations. Saw sealant
reservoirs and install the sealant
before opening
the pavement to
public traffic.
Table 501-6
501.12 Opening to
Construction
Equipment.
Protect
previously-constructed
lanes from damage by construction equipment.
Only allow equipment on the previously constructed
concrete after the
concrete attains
the appropriate
strength required
in Table 501-7.
Prepare and test
concrete
test
specimens according to Section
501.15, or by an
approved alternate test†††.
Table 501-7
(1) Includes: Concrete mixer trucks, dump trucks, water trucks, etc.
(2) The original research (References 6 and 7) used flexural strength criteria. The values
shown here were developed for granular subbases [Modulus of Subgrade Reaction k=27
MPa/m (100 psi/in.)] using the correlation equation: fr = C (f'cr)0.5 Where: fr = flexural
strength, MPa (psi); C = a constant, 0.75 metric (9 U.S.); f'cr = compressive strength,
MPa (psi).
(3) Operate light equipment (walk-behind saws, profilographs, motorized carts, etc.) as
needed without marring or damaging the surface of the pavement or, in the case of
sawing, without causing excessive raveling along the cut (see Section 501.07.1).
(4) Assumes there will be 50 passes of the fully-loaded vehicle.
†††
Note to the specification writer - To make it easier and
faster to obtain test results, certain highway agencies and
construction management firms use non-destructive testing
for opening-to-traffic strength measurements. Alternate test
methods include maturity (ASTM C 1074), pulse-velocity
(ASTM C 597), pullout (ASTM C 900), break-off (ASTM C
1150), penetration resistance (ASTM C 803), or rebound
hammer (ASTM C 805). The statistical variation of each
non-destructive test differs from cylinder compressive
strength tests. Before allowing a contractor to use one of
the alternate tests, ask for a demonstration of the test
including a comparison to compressive strength cylinder
testing. [Do not consider these non-destructive tests as
alternates in the strength acceptance procedure prescribed
in Section 501.17, because the statistical pay parameter
was set up for compressive strength with a standard
deviation of 3.5 MPa (500 psi).]
11
Acceptance Criteria‡‡‡
501.13 Smoothness. After the concrete has sufficiently hardened, measure the finished surface smoothness of the
pavement as specified below. Move all equipment, objects and debris that may interfere with the measuring
equipment or affect the measurement results.
1. Profilograph measurement. Using a California Profilograph§§§, or an approved equivalent, measure the
smoothness of each lane parallel to the centerline according to ACPA Technical Bulletin TB006P.(8)
A) Exclusions: Exclude the following areas from must-grind bump and profile index determination:
•
•
•
•
•
Any section less than 15 m (50 ft).
Side streets less than or equal to 150 m (500 ft.) in length.
Sections 15 m (50 ft.) from bridge approaches or an existing pavement.
Acceleration and deceleration lanes, turning lanes, auxiliary lanes, or storage lanes.
Curves with radius less than or equal to 300 m (1000 ft.) including superelevation transitions, such
as at ramps.
• Surfaces near manholes, inlets and other in-pavement utility castings.
• Driveway aprons.
• Bridge decks.
Locate bumps in any of these excluded
areas using a 3-m (10-ft) straightedge in
accordance with 501.13.2, unless otherwise specified.
Table 501-8
D) Defective areas: Defective areas are
must-grind bumps and profile indices
exceeding the index shown in Table
501-8. Defective areas require correction as outlined in Section 501.13.3.
E) Must grind bumps: Correct bumps (areas represented by high points on the profile trace) having
deviations in excess of 10 mm (0.4 in.) in 7.62 m (25 ft).
F) Profile Index: From the profile trace, calculate a profile index for each 0.1 km (0.1 mi) segment of lane
using a 5-mm (0.2-in.) wide blanking band. Include the profile trace for pavement lengths less than
0.1 km (0.1 mi) with the next segment for that lane when calculating the profile index. Determine the
profile index as prescribed in ACPA Technical Bulletin TB006P.(8)
Refer to section 501.13.4 and Table 501-9 for specific profile index requirements and to determine
the smoothness pay factor.
‡‡‡
Note to specification writer - This section contains acceptance criteria for smoothness, thickness, opening strength and
quality-assurance strength. Quality assurance testing for strength is applicable only to larger projects [17,500 m3 (21,000
yd 3 ) recommended] that will generate enough testing data to produce reasonable average values. On small projects, erratic
strength test results on any day might overly influence a project's strength statistics, producing an untrue mean and risking
acceptance of poor quality concrete or rejection of good quality concrete. To avoid this situation, omit quality-assurance
strength testing (Section 501.17) for smaller projects. Instead, use a more traditional approach and specify a mixture to the
contractor. If necessary, consult your state's standards or your local ready-mix suppliers for their recommendations on a
mixture for your application.
§§§ Note to specification writer - The California profilograph is the predominant
smoothness-measuring tool used in North America for evaluating newly constructed pavement (see reference 8). Many agencies and contractors employ a
California profilograph because it can provide results faster than most other
devices. However, its use may not be appropriate for some street and local road
projects if the paving lengths are too short. The California profilograph is not
recommended if paving segments are less than 150 m (500 ft). In these situations,
apply straightedge measurement as prescribed in 501.13.2.
12
2. Straightedge measurement. Use a 3-m (10-ft) metal straightedge to measure parallel to the centerline.
Where there is more than 6 mm in 3 m (1 /4 in. in 10 ft), between any two contacts of the straightedge with
the surface, the surface requires correction. Pavement surfaces that have been purposely warped to
meet fixtures (manholes, drainage inlets, catch basins), existing curb and gutter, or cross- and side-road
connections are exempt from this straightedge requirement.
3.
Defective area correction. Correct defective areas using an
approved grinding device****. After correction, verify the corrective work by measuring the smoothness according to 501.13.1
or 501.13.2, as appropriate.
At your (the contractor's) option, where measuring by California
Profilograph, correct the profile of any segment to improve the
profile index before determining the smoothness incentive. The
contractor is responsible to pay for correcting all defective areas.
4.
Determine smoothness
incentive.
California
Profilograph: Use Table
501-9 to determine the pay
incentive for each paving
segment subject to
smoothness evaluation by
California Profilograph.
Table 501-9
Straightedge: There is no
payment incentive for
properly corrected pavement, which is subject to
smoothness measurement
by 3-m (10-ft) straightedge. If bump grinding
does not correct a defective area, and the Engineer determines that the
defective area shall remain
in place, it is subject
to payment at 50% of
the area unit price. The Engineer may elect to require
removal and replacement
of any defective area that Where: PI = Measured Profile Index.
the Contractor cannot corls = Smoothness Incentive.
rect adequately.
501.14 Tolerance in Pavement Thickness: Determine the pavement thickness from cores by average caliper
measurements in accordance with AASHTO T 148 or ASTM C 174. Extract one core for each 140 m2
(1500 yd2) of concrete pavement placed in each lane. For pavement placement units consisting of less than
140 m2 (1500 yd2) of concrete, include the pavement with the previous or next placement unit.
Full payment will be made for pavement represented by cores that are no less than the Plan thickness minus
6 mm (0.25 in.)††††.
**** Note to specification writer - A grinding machine for bump grinding typically uses a cutting head with many diamond
saw-blades. The grinding head produces 164-197 grooves/meter (50-60 grooves/foot) and can remove 3-20 mm (1/8-3/4 in.
from the pavement surface. Carbide milling or other impact equipment may not produce as smooth a surface and are not
normally acceptable.
††††
Note to specification writer - See footnote on page 3 for prepared roadbed-trimming tolerance.
13
Pavement represented by cores that are less
than the Plan thickness minus 6 mm (0.25 in.)
are subject to further evaluation. Take two additional cores, one about 10 m (30 ft) before and
another about 10 m (30 ft) after the original core
(within the same placement unit). The work is
subject to full payment if the average thickness
of the three cores is no less than the Plan
thickness minus 6 mm (0.25 in.). Adjust the area
contract unit price as shown in Table 501-10 if
the average of three cores is no less than 25 mm
(1 in.) below the Plan thickness. If the average of
three cores is less than 25 mm (1 in.) below the
Plan thickness, and the Engineer determines
that the placement unit should remain in place,
it is subject to a 50% reduction to the area unit
bid price.
Table 501-10.
501.15 Testing and Test Specimens: Employ only testing laboratories meeting the requirements of ASTM C 1077
for preparing, handling, coring, storing and testing concrete specimens. Obtain the written qualifications of
the testing firm, indicating their compliance with ASTM E 329 "Standards of Recommended Practice for
Inspection and Testing Agencies for Concrete, Steel, and Bituminous Materials as Used in Construction."
Obtain the most recent certificates of calibration for testing equipment, showing that the equipment has been
calibrated at a minimum 12-month interval by devices of accuracy traceable to either National Bureau of
Standards or an established value. Submit to the Engineer all certification records for the testing firm and
equipment with the Strength Evaluation Plan according to section 501.17.1.
Obtain, handle and cure concrete test specimens for opening strength and thickness evaluation according
to applicable sections of AASHTO T 23 or ASTM C 31 or CSA A23.2-3C. Test the specimens according to
applicable sections of AASHTO T 22 or ASTM C 39 or CSA A23.2-9C.
The Engineer pays for the costs of coring and acceptance testing. The Contractor is responsible for costs
of extra or exploratory cores or tests to determine the extent of thickness or strength deficiencies.
15 Steps in Properly Making, Handling, Storing and Testing Concrete Cylinder Specimens
Improper handling and testing of concrete cylinders is found to contribute to low strength in a majority of strength
investigations. It is essential to employ trained testing personnel that are able to properly follow these strengthtesting standard procedures for field-made, laboratory-cured cylinders:
1. Sample concrete in two increments after discharging some from the chute or truck.
2. Transport sample to field curing location where it will remain for first clay.
3. Remix the sample concrete to ensure homogeneity.
4. Add concrete to cylinder molds that conform to standards- rod the concrete in three layers and tap sides of the
mold to close rod holes.
5. Finish top smooth and level with mold.
6. If necessary move cylinders immediately after molding; support the cylinder bottoms.
7. Field-cure cylinders at 15 to 27°C (60 to 80°F) and protect from loss of moisture.
8. Gently transport clay-old cylinders to the laboratory.
9. De-mold cylinders and promptly place in 21 to 24°C (70 to 76°F) moist curing environment.
10. Maintain water on cylinder surfaces at all times.
11. Before testing, cap cylinders with 34.5 MPa (5000 psi) capping material-make caps flat, true and no greater
than 5 mm (3/16 in.) thick.
12. Wait at least two hours for sulfur caps to harden.
13. Measure cylinder diameter and check cap quality, including alignment.
14. Using calibrated testing machine, center cylinder in testing head and load using proper loading rate.
15. Observe break pattern (vertical cracks through the cap indicate improper load distribution).
Nearly all deficiencies in handling and testing cylinders will lower measured strength. The most common errors
include: leaving cylinders for extra days of field-curing; allowing cylinders to fall, tip over or bounce during transportation; delaying moist-curing in the lab; and testing with improperly made and aligned caps.
14
501.16 Opening to Public Traffic. Cast at least three sets of three concrete cylinder specimens from each
pavement placement unit that exceeds 50 m3 (50 yd3) for testing the opening strength. Cast at least one set
of three cylinder specimens for pavement placement units less than 50 m3 (50 yd3) for testing the opening
strength.
Table 501-11
Choose‡‡‡‡ a time to test one cylinder specimen
from each of the three sets and average the
results to establish a test value. If the test value
complies with the specified opening strength,
open the pavement represented by the test
value. If the test value is not adequate for opening, test a second specimen (and third if necessary) from each of the three sets at later times to
establish additional test values. If the second
(and third where necessary) test value exceeds
or complies with the specified opening strength,
open the pavement placement unit represented
by the test value.
In the event that none of the three average test
values exceed or comply with the specified
opening strength, plot the test values on a graph
and draw a straight line through the points in
such a manner as to establish a linear agestrength relationship. Project the line to 14 days,
and open the pavement at the age where the line
indicates opening strength compliance. If the
time between the first and third test is not at least
4 days, then consult the Engineer on alternate
strength testing at your (the contractor's)
expense.
(1) Test strength test specimens using AASHTO T 23 or
ASTM C 31 or CSA A23.2-3C.
(2) The original research (Reference 4) used flexural
strength criteria. The values shown here were developed for granular subbases [Modulus of Subgrade
Reaction k=27 MPa/m (100 psi/in.)] using the correlation equation: fr = C (f'cr)0.5 Where: fr = flexural
strength, MPa (psi); C = a constant, 0.75 metric
(9 U.S.); f'cr = compressive strength, MPa (psi).
(3) Assumes there will be 500 one-way equivalent single
axle load (ESAL) repetitions between time of opening
and time concrete reaches design strength (28-day
strength).
Do not allow public traffic on the pavement until
the concrete attains the appropriate strength
required in Table 501-11.
‡‡‡‡
Note to specification writer - Consider four days for initially testing normal concrete, 3 days for accelerated concrete
and 24 hours for fast-track concrete. Consider taking subsequent tests every 2 days for normal mixtures, 1 day for accelerated and fast-track mixtures. Opening requirements may necessitate testing earlier than 24 hours for projects using fasttrack mixtures. As an alternate to compressive, consider non-destructive methods (see note, page 11).
15
501.17 Concrete Strength Evaluation: Evaluate concrete strength using compressive strength of cylinders and the
procedures prescribed herein.
1. Strength Evaluation Plan. Before beginning any work, submit a written Strength
Evaluation Plan to the Engineer outlining
details of the sampling and testing methodology for the project, including the nominal
sublot size for strength evaluation. Include
copies of the equipment calibration, and
personnel and laboratory certification information as required in Section 501.15.
Stength Evaluation Plan The strength evaluation plan does not need to be an
overly complex or lengthy document. It should contain
the appropriate information to describe the contractor's
understanding and planned activities for strength evaluation. The Engineer will evaluate the plan and use its
content to monitor the contractor during construction.
Should the contractor deviate from his written plan, without prior approval from the Engineer, the concrete represented by the deviation is subject to alternate testing
for strength compliance.
2. Sampling. The size of a lot for strength
evaluation consists of the quantity of concrete placed during each day (a pavement
placement unit). Do not combine areas containing different concrete mixtures or designs into one lot. A change in the mixture
proportioning or design requires a change
in the lot. A change in the placement technique requires a change in the lot. Any
pavement placement unit requiring 50 m3
(50 yd3) or less of concrete is exempt from
inclusion in QA/QC requirements.
Most quality-assurance and quality control specifications require the contractor to submit a "quality control
plan" before construction. In addition to strength evaluation, this plan also outlines the project construction
methodology, decision-making hierarchy and project
personnel responsibilities.
Use a minimum of four sublots per lot. No sublot may exceed 500 m3 (500 yd3). Add any paving areas
that are not represented by a full sublot to the previous sublot for strength evaluation. Use all available
tests to determine the average strength for the combined sublot.
If less than four random samples are available to represent concrete in a pavement placement unit, (less
than 4 samples are taken during a given day) incorporate the concrete into the following or previous lot.
Pay adjustments for compressive strength is on a lot-by-lot basis. Acceptance or rejection of concrete
is on a sublot-by-sublot basis.
3.
Evaluating Sublots. Cast two concrete cylinder specimens from each sublot. Test the specimens 28
days from the day of placement. Determine the average compressive strength of the two cylinder
specimens using tests and specimens treated according to section 501.15. The concrete in the sublot
does not warrant further testing if the compressive strength value of each cylinder equals or exceeds
17.25 MPa (2500 psi). If either cylinder strength falls below 17.25 MPa (2500 psi), evaluate the concrete
using the procedure in Section 501.19.
16
4.
Evaluating Lots. Using all of
the sublot strengths in each
lot [each average of two
cylinders, including averages
below 17.25 MPa (2500 psi)]
calculate the
average
compressive strength and
standard deviation for the lot.
Subtract the standard
deviation from the average
compressive strength to
determine the "pay strength."
Consult Table 501-12 to
determine the pay adjustment
factor for the lot.
Table 501 -12§§§§
Where:
PS = Pay strength (average compressive strength minus one standard
deviation).
DS = Average design compressive strength.
As = Compressive strength pay adjustment factor.
Sensitivity of Pay to
Standard Deviation:
Contractors producing
concrete at a lower
standard deviation
(better control) earn an
opportunity for an
incentive at a lower
average strength than
contractors operating
with less control.
§§§§ Note to specification writer - Use the designer's strength value to complete Table 501-12. Most design procedures
(including AASHTO) are based upon the average 28-day flexural strength. Consult the design engineer to determine the
value used for the project, convert it from flexural strength if necessary, and place it in Table 501-12 at each location denoted
by DS.
If a mixture-specific correlation is unavailable for the mixture employed on this project, convert between flexural and compressive strength using the approximate correlation equation: fr = C (f'cr)0.5
Where: fr = flexural strength, MPa (psi); C = a constant, 0.75 metric (9 U.S.); f'cr = compressive strength, MPa (psi).
If the design strength for this project is unavailable, select a value of 28 MPa (4000 psi), which is typical for most street and
local road projects.
Do not use the "minimum strength" as required in a past version of your state or local road specifications to represent the
average design compressive strength in this specification. To meet these previous "minimum strength" specifications,
contractors were required to use concrete designed to exceed the minimum by a large margin. This previous method of
specification and accompanying over-design is not consistent with the principles of these acceptance criteria.
17
This method assumes that the standard deviation of compressive strength in the design is 3.5 MPa (500
psi). This standard deviation is essentially consistent with the recommendation in American Concrete
Institute 318(9), [3.8 MPa (550 psi)] and the experience of ready-mix producers for good quality concrete.
The range of strength between the average design compressive strength (DS) and one standard deviation
above and below accounts for variability in design and construction.
Contingency Criteria
501.19 Referee Testing: Apply referee testing for any of the following conditions:
• When compressive strength evaluation in Section 501.17.3 indicates the concrete is not above 17.25
MPa (2500 psi).
• Test specimens are of suspect quality, fabrication, transport or curing.
• Testing procedures or test machines are of suspect quality or calibration.
Remove three cores at random locations in the suspect area after the concrete pavement is at least 28 days
old. Remove, handle and test the compressive strength of the three cores according to AASHTO T 24 or
ASTM C 42, or CSA A23.2-14C.
Determine the mean and standard deviation of the compressive strength of the three cores.***** If the mean
exceeds 14.85 MPa (2150 psi), and no one core test is less than 12.93 MPa (1875 psi), the concrete in the
sublot is subject to payment according to Table 501-12 using the results from the cores. Otherwise, the
concrete is not acceptable and may be removed and replaced at the Engineer's option.
***** Note to specification writer - The compressive strength of cores is normally 85 percent or less than the compressive
strength of 28-day cylinder specimens that have been properly made, cured and tested. This referee method applies this 85
percent relationship to validate the cylinder test results. The mean minus one standard deviation of the compressive
strengths of the three cores becomes a pay strength test result if it indicates that the concrete (by valid cylinder testing)
would exceed 17.25 MPa (2500 psi). This method is adapted from ACI 318(9).
18
501.20 Repairing Defects:††††† Repair defects in conformance with Table 501-13. Do not begin corrective work until
after submitting a plan and receiving the Engineer's approval for repair methods.
Table 501-13 Repair Methods for Defects in New Pavement
1. 1 m = 3.28 ft
2. HMWM = High molecular weight methacrylate poured over surface and sprinkled with sand for skid resistance.
3. LTR = load-transfer restoration; 3 dowel bars per wheel path grouted into slots sawed across the crack; Slots must be
parallel to each other and the longitudinal joint.
4. FDR = full-depth repair; 3 m (10 ft) long by one lane wide. Extend to nearest transverse contraction joint if 3-m (10-ft)
repair would leave a segment of pavement less than 3 m (10 ft) long.
5. PDR = partial-depth repair; Saw around spall leaving 50 mm (2 in.) between spall and 50-mm (2-in.) deep perimeter saw
cuts. Chip concrete free, then clean and apply bond-breaker to patch area. Place a separating medium along any
abutting joint or crack. Fill area with patching mixture.
6. Cross-stitching; for longitudinal cracks only, drill holes at 35° angle, alternating from each side of joint on 750-1000 mm
(30-36 in.) spacing. Epoxy deformed steel tiebars into holes.
†††††
For details on the recommended practices for design and construction of the repair methods recommended in Table
501-13, see references 10-13.
19
Final Completion
501.21 Final Completion. Complete all items in accordance with the Plans and these specifications before seeking
final acceptance. Remove all equipment, surplus material, and construction debris from the project area.
Measurement
501.22 Measurement: Measure the pavement by area for placing and by volume for furnishing concrete.
Determine the total area quantity for payment by adding all non-rectangular paved areas to the primary
paved area in this contract. The width for calculating the primary paved area is the width of the pavement
shown on the cross-section in the plans, including any additional widening required by the Engineer. The
length for calculating the primary paved area is the distance along the pavement centerline. For intersections, tapers and other non-rectangular areas, calculate the area of each unusual shape separately.
Determine the volume of each different concrete mixture furnished for the project by adding the quantities
indicated on the batch tickets.
Payment
501.23 Payment: The area unit price is compensation for furnishing all labor, equipment, and materials to place,
finish, texture, cure, saw joints and seal joints, in accordance with the Plans and these specifications. The
concrete volume unit price is compensation for furnishing all raw materials, and for proportioning, mixing
and delivering concrete to the paving machine. All pavement accepted by the Engineer will be paid at the
contract price per unit for the pay items shown in the bid schedule, except as follows:
•
Each lot/pavement placement unit is subject to the requirements in Section 501.17 and adjustment to
the concrete volume unit bid price as follows:
PPV = UBPV • As
Where:
•
PPV = Price paid per unit volume
UBPV = Volume unit bid price
As
= Strength pay adjustment factor determined in Table 501-12
Each lot/pavement placement unit is subject to the requirements of Section 501.13 and 501.14 and
adjustment to the area unit bid price as follows:
PPA = (UBPA + l s ). ( PFT)
Where:
PPA
UBPA
ls
PFT
= Price paid per unit area
= Area unit bid price
= Smoothness incentive determined in Table 501-9
= Pay factor determined in Table 501-10
20
Joint Details
Contraction:
Construction:
Isolation:
21
Details for Boxing out Utilities§§§§§
Notes on Details:
1. Isolation joints should be at least 12 mm (1/2 in.) wide and filled with a compressible material.
2. Boxouts should be large enough to provide at least 0.3 m (1 ft) of clearance between the fixture and the surrounding
isolation joint.
§§§§§
Note to specification writer - There is no need to include a special section in the project specifications to prescribe the
manner of handling in-pavement fixtures if details are included on the Plans. For utility fixtures such as manholes, catch
basins and drainage inlets, the need for isolation will depend upon the casting design. Non-telescoping manholes with
ribbed cylinder walls usually require a boxout with perimeter isolation joint to allow vertical and horizontal slab movement.
Check your agency's standards to determine the allowable casting models. If necessary, consider expanding the allowable
list to include smooth-walled and telescoping models, which facilitate pavement construction by allowing placement of the
fixture without requiring a boxout.
Boxing out fixtures may be undesirable in some circumstances. For instance, boxouts can impede fast-track construction
because more time is needed to place concrete around the casting after the pavement gains strength. It is also very difficult
to maintain a uniform joint pattern if there are too many manholes randomly positioned in an intersection. In these cases it
may be best to cast the fixtures into the concrete.
Square manhole boxouts sometimes cause cracks to form at the boxout's corners. Consequently, the detail above includes
the placement of reinforcing bars at interior corners. To avoid crack-inducing corners, consider using the diagonal, circular,
or square boxout with fillets.
To isolate a fixture without a boxout, some contractors and agencies wrap the casting with expansion joint filler. Other
experienced contractors successfully cast fixtures with smooth cylinder walls, and telescoping fixtures directly into the
concrete. Telescoping manhole fixtures have a two-piece casting, which allows the height to be adjusted after concrete
placement.
22
Table A-1
Identification:
1. Project.
2.
Name and address of Contractor and concrete producer.
3.
Mixture designation.
4.
Class of concrete and intended use.
Materials and Proportions:
1. Name and location of material sources for aggregate, cement, admixtures, and water.
2. Type of cement and additives (if used).
3.
Cement content in kilograms per cubic meter (pounds per cubic yard) of concrete.
4. The water/cement ratio for modified concrete is the ratio of the mass of water to the combined masses of
portland cement and supplementary cementitious material.
5. The saturated surface dry batch mass of the coarse and fine aggregate in kilograms per cubic meter (pounds
per cubic yard) of concrete.
6. Water content (including free moisture in the aggregate plus water in the drum, exclusive of absorbed moisture
in the aggregate) in kilograms per cubic meter (pounds per cubic yard) of concrete.
7. Target water/cementitious ratio.
8.
Dosage of admixture(s). Entrained air may be obtained either by the use of an air-entraining portland cement or
by the use of an air-entraining admixture.
9.
Sieve analysis of aggregates.
10. Absorption of fine and coarse aggregate.
11. Bulk specific gravity (dry and saturated surface dry) of fine and coarse aggregate.
12. Dry rodded unit mass of coarse aggregate in kilograms per cubic meter (pounds per cubic yard).
13. Fineness modulus (FM) of fine aggregate.
14. Concrete unit mass.
15. Material certifications for portland cement, admixtures, and aggregate.
Plastic and Hardened Properties:
1. Target values for concrete slump (provide slump targets with and without high-range water reducers, where the
mixture incorporates high-range water reducers).
2. Target values for concrete air content. Include the proposed range of air content for concrete to be incorporated into the work. Describe the methods by which air content will be monitored and controlled. Provide acceptable documentation that the slump and compressive strength of the concrete are within specified limits
throughout the full range of proposed air content.
3. Average compressive strength of concrete at 7, 14 and 28-days. Report compressive strength at other times as
necessary for expected opening to traffic requirements.
4. Correlation factor for compressive to flexural strength.
23
References
1. Guide Specifications for Highway Construction, American Association of State Highway and Transportation
Officials, Washington, DC, 1993.
2.
Guide Specifications for Concrete Subject to Alkali-Aggregate Reactions, IS415T, Portland Cement Association,
American Concrete Pavement Association, Skokie, IL, 1995.
3. Farny, J., Kosmatka, S., Diagnosis and Control of Alkali-Aggregate Reactions in Concrete, IS413T, Portland
Cement Association, American Concrete Pavement Association, Skokie, IL, 1997.
4.
Guidelines for Protection and Repair of Concrete Pavements Exposed to Rain During Construction, American
Concrete Pavement Association, Arlington Heights, IL, 1987.
5.
Concrete Pavement Surface Textures, SR902P, American Concrete Pavement Association, Skokie, IL, 1998.
6. Okamoto, P. and others, Guidelines for Timing Joint Sawing and Earliest Loading for Concrete Pavement, Volume
1 - Final Report, FHWA-RD-91-079, Federal Highway Administration, Washington, DC, February 1994.
7. Fast-Track Concrete Pavements, TB004P, American Concrete Pavement Association, Skokie, IL, 1994.
8.
Constructing Smooth Concrete Pavements, TB006P, American Concrete Pavement Association,
Skokie, IL, 1990.
9. Building Code Requirements for Reinforced Concrete, ACI 318-95, American Concrete Institute,
Detroit, Ml, 1995.
10. Guidelines for Full-Depth Repair, TB002P, American Concrete Pavement Association, Skokie, IL, 1995.
11. Guidelines for Partial-Depth Repair, TB003P, American Concrete Pavement Association, Skokie, IL, 1998.
12. Joint and Crack Sealing and Repair for Concrete Pavements, TB012P, American Concrete Pavement Association, Skokie, IL, 1993.
13. Concrete Pavement Rehabilitation Guide for Load Transfer Restoration, JP001P, American Concrete Pavement
Association, Skokie, IL, 1997.
14. Quality Assurance Guide Specification, Subcommittee on Construction, American Association of Highway and
Transportation Officials, Washington, DC, February 1996.
This publication is intended SOLELY for use by PROFESSIONAL PERSONNEL who are competent to evaluate the significance and
limitations of the information provided herein, and who will accept total responsibility for the application of this information.
The American Concrete Pavement Association DISCLAIMS any and all RESPONSIBILITY and LIABILITY for the accuracy of and
the application of the information contained in this publication to the full extent permitted by law.
American Concrete Pavement Association 5420 Old Orchard Road, Suite A100, Skokie, Illinois 60077-1083
(847) 966-2272, FAX (847) 966-9970, Web Site@www.pavement.com
A national organization with the mission to increase the use
of concrete pavement in construction and rehabilitation of
transportation facilities in North America, by continually
providing a quality product that is safe, cost effective and
environmentally sound.
IS119.02P
Printed in U.S.A.
24