Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10)

Page 6-8

Concrete Structures

Concrete of a numerical class greater than 4000 shall conform to the requirements
specified for either Class 4000 (if general-purpose) or for the appropriate Class 4000 with
a letter suffix, as follows:
1. Mix design and proportioning specified in Sections

6-02.3(2)

6-02.3(2)A

and

6-02.3(2)A1

2. Consistency requirements specified in

Section 6-02.3(4)C

3. Temperature and time for placement requirements specified in

Section 6-02.3(4)D

4. Curing requirements specified in

Section 6-02.3(11)

The Contractor may request, in writing, permission to use a different class of concrete
with either the same or a higher compressive strength than specified. The substitute
concrete shall be evaluated for acceptance based on the specified class of concrete. The
Engineer will respond in writing. The Contractor shall bear any added costs that result
from the change.

6-02.3(2) Proportioning Materials

The soluble chloride ion content shall be determined by the concrete supplier and
included with the mix design. The soluble chloride ion content shall be determined by
(1) testing mixed concrete cured at least 28 days or (2) totaled from tests of individual
concrete ingredients (cement, aggregate, admixtures, water, fly ash, ground granulated
blast furnace slag, and other supplementary cementing materials). Chloride ion limits for
admixtures and water are provided in Sections

9-23

and

9-25

. Soluble chloride ion limits

for mixed concrete shall not exceed the following percent by mass of cement when tested
in accordance with AASHTO T260:

Category

Acid-Soluble

Water-Soluble

Prestressed concrete

0.08

0.06

Reinforced concrete

0.10

0.08

Unless otherwise specified, the Contractor shall use Type I or II portland cement or
blended hydraulic cement in all concrete as defined in

Section 9-01.2(1)

The use of fly ash is required for Class 4000P concrete, except that ground granulated
blast furnace slag may be substituted for fly ash at a 1:1 ratio. The use of fly ash and
ground granulated blast furnace slag is optional for all other classes of concrete and may
be substituted for portland cement at a 1:1 ratio as noted in the table below.

Concrete Structures

6-02

Cementitious Requirement for Concrete

Class of

Concrete

Minimum

Cementitious

Content

(Pounds)

Minimum percent

Replacement of

Fly Ash or Ground

Granulated Blast

Furnace Slag for

Portland Cement

Maximum percent

Replacement of Fly

Ash for Portland

Cement

Maximum percent

Replacement of

Ground Granulated

Blast Furnace Slag

for Portland Cement

4000

564

4000A

564

4000P

600

4000W

564

3000

564

Commercial

Concrete

**564

Pumpable

Lean Concrete

***

Lean Concrete

****145

*No minimum specified.
**For Commercial Concrete, the minimum cementitious content is only required for sidewalks, curbs, and
gutters.
***No maximum specified.
****Maximum of 200 pounds

When both ground granulated blast furnace slag and fly ash are included in the concrete
mix, the total weight of both these materials is limited to 40 percent by weight of the total
cementitious material for concrete class 4000A, and 50 percent by weight of the total
cementitious material for all other classes of concrete.

The water/cement ratio shall be calculated on the total weight of cementitious material.
Cementitious materials are those listed in

Section 5-05.2

. With the Engineer’s written

concurrence, microsilica fume may be used in all classifications of Class 4000, Class
3000, and commercial concrete and is limited to a maximum of 10 percent of the
cementitious material.

As an alternative to the use of fly ash, ground granulated blast furnace slag and cement as
separate components, a blended hydraulic cement that meets the requirements of Section
9-01.2(1)B Blended Hydraulic Cements may be used.

6-02.3(2)A

Contractor Mix Design

The Contractor shall provide a mix design in writing to the Engineer for all classes
of concrete specified in the Plans except for lean concrete, commercial concrete
and concrete class EA. No concrete shall be placed until the Engineer has reviewed
the mix design. The required average 28-day compressive strength shall be selected
in accordance with ACI 301, Chapter 4, Section 4.2.3.3. ACI 211.1 shall be used to
determine proportions. All proposed concrete mixes except Class 4000D shall meet the
requirements in Cementitious Requirement for Concrete in

Section 6-02.3(2)

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Concrete Structures

The Contractor’s submittal of a mix design shall be on WSDOT

Form 350-040

and

shall provide a unique identification for each mix design and shall include the mix
proportions per cubic yard, the proposed sources, the average 28-day compressive
strength for which the mix is designed, the fineness modulus, and the water cement
ratio. The mix design submittal shall also include test results no older than one year
showing that the Aggregates do not contain Deleterious Substances in accordance with
Section 9-03. Concrete placeability, workability, and strength shall be the responsibility
of the Contractor. The Contractor shall notify the Engineer in writing of any mix design
modifications.

Fine aggregate shall conform to

Section 9-03.1(2)

Class 1 or Class 2.

Coarse aggregate shall conform to

Section 9-03

. An alternate combined aggregate

gradation conforming to

Section 9-03.1(5)

may also be used. The nominal maximum size

aggregate for Class 4000P shall be ⅜ inch. The nominal maximum size aggregate for Class

4000A shall be 1 inch.

Nominal maximum size for concrete aggregate is defined as the smallest standard sieve
opening through which the entire amount of the aggregate is permitted to pass.

A retarding admixture is required in concrete Class 4000P.

Air content for concrete Class 4000D shall conform to

Section 6-02.3(2)A1

. For all other

concrete, air content shall be a minimum of 4.5 percent and a maximum of 7.5 percent for
all concrete placed above the finished ground line unless noted otherwise.

6-02.3(2)A1 Contractor Mix Design for Concrete Class 4000D

All Class 4000D concrete shall conform to the following requirements:
1. Aggregate shall use combined gradation in accordance with

Section 9-03.1(5)

with a

nominal maximum aggregate size of 1½ inches.

2. Permeability shall be less than 2,000 coulombs at 56 days in accordance with

AASHTO T277.

3. Freeze-thaw durability shall be provided by one of the following methods:

a. The concrete shall maintain an air content between 4.5 and 7.5 percent.
b. The concrete shall maintain a minimum air content that achieves a durability

factor of 90 percent, minimum, after 300 cycles in accordance with AASHTO
T 161, Procedure A. This air content shall not be less than 3.0 percent.
Test samples shall be obtained from concrete batches of a minimum of
3.0 cubic yards.

4. Shrinkage at 28 days shall be less than 0.032 percent in accordance with AASHTO

T 160.

5. Density shall be measured in accordance with ASTM C138.

Concrete Structures

6-02

The Contractor shall submit the mix design in accordance with

Section 6-02.3(2)A

. The

submittal shall include test reports for all tests listed above that follow the reporting
requirements of the AASHTO/ASTM procedures. Mix designs using shrinkage reducing
admixture shall state the specific quantity required. Samples for testing may be obtained
from either laboratory or concrete plant batches. If concrete plant batches are used, the
minimum batch size shall be 3.0 cubic yards. Testing samples of mixes using shrinkage
reducing admixture shall use the admixture amount specified in the mix design submittal.
The Contractor shall submit the mix design to the Engineer at least 30 calendar days prior
to the placement of concrete in the bridge deck.

6-02.3(2)A2 Contractor Mix Design for Self-Consolidating Concrete

Self-consolidating concrete (SCC) is concrete that is able to flow under its own weight
and completely fill the formwork without the need for vibration while maintaining
homogeneity, even in the presence of dense reinforcement. SCC shall be capable of being
pumped, and of flowing through the steel reinforcing bar cage without segregation or
buildup of differential head inside or outside of the steel reinforcing bar cage.

Type III cement may be used in SCC.

SCC may be used for the following concrete Structure elements:
1. All cast-in-place concrete elements except bridge decks, bridge approach slabs, and

any cast-in-place concrete element excluded by the Special Provisions.

2. Prestressed concrete girders in accordance with

Sections 6-02.3(25)

3. All precast concrete elements identified in

Section 6-02.3(27)A

The mix design submittal shall include items specified in

Section 6-02.3(2)A

and results

of the following tests conducted on concrete that has slump flow within the slump flow
range defined below:
1. Slump Flow.

a. The mix design shall specify the target slump flow in inches, in accordance with

WSDOT FOP for ASTM C1611. The slump flow range is defined as the target
slump flow plus or minus 2-inches.

b. The visual stability index (VSI) shall be less than or equal to 1, in accordance

with ASTM C1611, Appendix X1, using Filling Procedure B.

c. The T50 flow rate results shall be less than 6-seconds in accordance with ASTM

C1611, Appendix X1, using Filling Procedure B.

2. Column Segregation.

a. The maximum static segregation shall be 10-percent in accordance with ASTM

C1610.

b. The Maximum Hardened Visual Stability Index (HVSI) shall be 1 in accordance

with AASHTO PP 58.

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Concrete Structures

3. J ring test results for passing ability shall be less than or equal to 1.5-inches in

accordance with the WSDOT FOP for ASTM C1621.

4. Rapid assessment of static segregation resistance of self-consolidating concrete

using penetration test in accordance with ASTM C1712 shall be less than or equal to
15 mm.

5. Air content shall be tested in accordance with WSDOT Test Method

T 818

, and shall

conform to

Section 6-02.3(2)A

6. Concrete unit weight results in pounds per cubic foot shall be recorded in

accordance with AASHTO T 121, except that the concrete shall not be consolidated
in the test mold.

7. The temperature of all concrete laboratory test samples shall be tested in accordance

with AASHTO T 309 and shall conform to the placement limits specified in

Section

6-02.3(4)D

8. The modulus of elasticity in pounds per square inch at 28 days shall be recorded in

accordance with ASTM C469.

In lieu of a Contractor-Provided mix design for SCC for

Section 6-02.3(27)A

Structure

elements 3, 7 and 8, a representative full-size example Structure element shall be cast
for inspection by the Contracting Agency in accordance with

Section 6-02.3(27)B

as a

component of the precast fabricating facility’s annual plant approval process.

6-02.3(2)B

Commercial Concrete

Commercial concrete shall have a minimum compressive strength at 28 days of 3,000 psi
in accordance with AASHTO T 22. Commercial concrete placed above the finished ground
line shall be air entrained and have an air content from 4.5 percent to 7.5 percent in
accordance with FOP for AASHTO T 152. Commercial concrete does not require mix
design or source approvals for cement, aggregate, and other admixtures.

Where concrete Class 3000 is specified for items such as, culvert headwalls, plugging
culverts, concrete pipe collars, pipe anchors, monument cases, Type PPB, PS, I, FB and
RM signal standards, pedestals, cabinet bases, guardrail anchors, fence post footings,
sidewalks, concrete curbs, curbs and gutters, and gutters, the Contractor may use
commercial concrete. If commercial concrete is used for sidewalks, concrete curbs, curbs
and gutters, and gutters, it shall have a minimum cementitious material content of 564
pounds per cubic yard of concrete, shall be air entrained, and the tolerances of

Section

6-02.3(5)C

shall apply.

Concrete Structures

6-02

6-02.3(2)C

Concrete Class EA

Concrete for members and surfaces specified to receive an exposed aggregate finish shall
be Class EA. Concrete Class EA shall conform to the following requirements:

28 day compressive strength

3,600 psi (minimum)

Cement

610 pounds per cubic yard

Fine Aggregate Class 1

880 pounds per cubic yard

Coarse Aggregate Grading No. 67 2,160 pounds per cubic yard
Water (maximum)

270 pounds per cubic yard

Water/Cement Ratio (maximum)

0.44

A Type A water reducing admixture conforming to Section 9-23.6 shall be used in
accordance with Section 6-02.3(3). Air content shall conform to Section 6-02.3(2)A.

Mixing water shall be the minimum required for satisfactory placement and shall not
exceed the specified amount.

Aggregate weights are based on a specific gravity of 2.67. Adjustments in the mix design
will be made by the Engineer as necessary to correct for actual bulk specific gravity of
the aggregates, moisture content of the aggregates, and to ensure proper consistency,
workability, and correct cement content per cubic yard of concrete.

6-02.3(2)D

Lean Concrete

Lean concrete shall meet the cementitious requirements of

Section 6-02.3(2)

and have a

maximum water/cement ratio of 2.

6-02.3(3) Admixtures

Concrete admixtures shall be added to the concrete mix at the time of batching the
concrete or in accordance with the manufacturer’s written procedure and as accepted by
the Engineer. A copy of the manufacturer’s written procedure shall be furnished to the
Engineer prior to use of any admixture. Any deviations from the manufacturer’s written
procedures shall be submitted as a Type 2 Working Drawing. Admixtures shall not be
added to the concrete with the modified procedures until the Engineer has concurred in
writing.

When the Contractor is proposing to use admixtures from different admixture
manufacturers they shall provide evidence to the Engineer that the admixture will be
compatible and not adversely affect the air void system of the hardened concrete. Test
results complying with ASTM C457 shall be provided as the evidence to satisfy this
requirement. Admixture combinations which have been previously tested and which are in
compliance with ASTM C457 shall be listed in the Qualified Products List (QPL). Proposed
combinations not found in the QPL shall meet this requirement.

Accelerators shall not be used.

Page 6-14

Concrete Structures

Accelerating admixtures conforming to Sections 9-23.6(4) or 9-23.6(6) and used in
accordance with the manufacturer’s recommendations may be used in cast-in-place
concrete, except as required here. Accelerating admixtures shall not be used in bridge
decks, all concrete superstructures, crossbeams, columns, mass concrete, or new bridge
approach slabs and expansion joints that are not part of a repair. Concrete placements
with the least dimension greater than 6 feet shall be considered mass concrete. Concrete
placement with the least dimension greater than 3 feet, but less than or equal than 6 feet,
shall require the approval of the Engineer for the use of accelerating admixtures. Shafts
shall not be considered mass concrete. Chloride based accelerating admixtures shall not
be used.

Air entrained cement shall not be used to air entrain concrete.

6-02.3(4) Ready-Mix Concrete

All concrete, except lean concrete shall be batched in a prequalified manual, semi-
automatic, or automatic plant as described in

Section 6-02.3(4)A

. The Engineer is not

responsible for any delays to the Contractor due to problems in getting the plant certified.

6-02.3(4)A

Qualification of Concrete Suppliers

Batch Plant Prequalification requires a certification by the National Ready Mix Concrete
Association (NRMCA). Information concerning NRMCA certification may be obtained
from the NRMCA at 900 Spring Street, Silver Springs, MD 20910 or online at

www.

nrmca.org

. The NRMCA certification shall be valid for a 2-year period from the date of

certificate. The following documentation shall be submitted to the Engineer; a copy of
the current NRMCA Certificate of Conformance, the concrete mix design(s) (WSDOT

Form 350-040

), along with copies of the truck list, batch plant scale certification,

admixture dispensing certification, and volumetric water batching devices (including water
meters) verification.

For central-mixed concrete, the mixer shall be equipped with a timer that prevents
the batch from discharging until the batch has been mixed for the prescribed mixing
time. A mixing time of 1 minute will be required after all materials and water have been
introduced into the drum. Shorter mixing time may be allowed if the mixer performance is
tested in accordance with (AASHTO M157 Annex A1 Concrete Uniformity Requirements).
Tests shall be conducted by an independent testing lab or by a commercial concrete
producer’s lab. If the tests are performed by a producer’s lab, the Engineer or a
representative will witness all testing.

For shrink-mixed concrete, the mixing time in the stationary mixer shall not be less than
30 seconds or until the ingredients have been thoroughly blended.

For transit-mixed or shrink-mixed concrete, the mixing time in the transit mixer shall
be a minimum of 70 revolutions at the mixing speed designated by the manufacturer
of the mixer. Following mixing, the concrete in the transit mixer may be agitated at the
manufacturer’s designated agitation speed. A maximum of 320 revolutions (total of mixing
and agitation) will be permitted prior to discharge.

Concrete Structures

6-02

All transit-mixers shall be equipped with an operational revolution counter and a
functional device for measurement of water added. All mixing drums shall be free of
concrete buildup and the mixing blades shall meet the minimum Specifications of the
drum manufacturer. A copy of the manufacturer’s blade dimensions and configuration
shall be on file at the concrete producer’s office. A clearly visible metal data plate (or
plates) attached to each mixer and agitator shall display: (1) the maximum concrete
capacity of the drum or container for mixing and agitating, and (2) the rotation speed of
the drum or blades for both the agitation and mixing speeds. Mixers and agitators shall
always operate within the capacity and speed-of-rotation limits set by the manufacturer.
Any mixer, when fully loaded, shall keep the concrete uniformly mixed. All mixers and
agitators shall be capable of discharging the concrete at a steady rate. Only those transit-
mixers which meet the above requirements will be allowed to deliver concrete to any
Contracting Agency project covered by these Specifications.

In transit-mixing, mixing shall begin within 30 seconds after the cement is added to
the aggregates.

Central-mixed concrete, transported by truck mixer/agitator, shall not undergo more than
250 revolutions of the drum or blades before beginning discharging. To remain below
this limit, the suppler may agitate the concrete intermittently within the prescribed time
limit. When water or admixtures are added after the load is initially mixed, an additional
30 revolutions will be required at the recommended mixing speed.

For each project, at least biannually, or as required, the Plant Manager will examine
mixers and agitators to check for any buildup of hardened concrete or worn blades. If
this examination reveals a problem, or if the Engineer wishes to test the quality of the
concrete, slump tests may be performed with samples taken at approximately the ¼ and
¾ points as the batch is discharged. The maximum allowable slump difference shall be
as follows:

If the average of the two slump tests is < 4 inches, the difference shall be < 1 inch
or if the average of the two slump tests is >4 inches, the difference shall be
< 1½ inches.

If the slump difference exceeds these limits, the equipment shall not be used until the
faulty condition is corrected. However, the equipment may continue in use if longer
mixing times or smaller loads produce batches that pass the slump uniformity tests.

All concrete production facilities will be subject to verification inspections at the
discretion of the Engineer. Verification inspections are a check for: current scale
certifications; accuracy of water metering devices; accuracy of the batching process; and
verification of coarse aggregate quality.

If the concrete producer fails to pass the verification inspection, the following actions will
be taken:
1. For the first violation, a written warning will be provided.

Page 6-16

Concrete Structures

2. For the second violation, the Engineer will give written notification and the

Contracting Agency will assess a price reduction equal to 15 percent of the invoice
cost of the concrete that is supplied from the time of the infraction until the
deficient condition is corrected.

3. For the third violation, the concrete supplier is suspended from providing concrete

until all such deficiencies causing the violation have been permanently corrected and
the plant and equipment have been reinspected and meets all the prequalification
requirements.

4. For the fourth violation, the concrete supplier shall be disqualified from supplying

concrete for 1 year from the date of disqualification. At the end of the suspension
period the concrete supplier may request that the facilities be inspected for
prequalification.

6-02.3(4)B

Jobsite Mixing

For small quantities of concrete, the Contractor may mix concrete on the job site provided
the Contractor has requested in writing and received written permission from the
Engineer. The Contractor’s written request shall include a mix design, batching and mixing
procedures, and a list of the equipment performing the job-site mixing. All job site mixed
concrete shall be mixed in a mechanical mixer.

If the Engineer permits, hand mixing of concrete will be permitted for pipe collars, pipe
plugs, fence posts, or other items receiving the concurrence of the Engineer, provided the
hand mixing is done on a watertight platform in a way that distributes materials evenly
throughout the mass. Mixing shall continue long enough to produce a uniform mixture.
No hand mixed batch shall exceed ½ cubic yard.

Concrete mixed at the jobsite is never permitted for placement in water.

6-02.3(4)C Consistency

The maximum slump for concrete shall be:
1. 3½ inches for vibrated concrete placed in all bridge decks, bridge approach slabs, and

flat slab bridge Superstructures.

2.  4½ inches for all other vibrated concrete.
3.  7 inches for non-vibrated concrete. (Includes Class 4000P)
4.  9 inches for shafts when using Class 4000P, provided the water cement ratio

does not exceed 0.44 and a water reducer is used meeting the requirements of

Section 9-23.6

5. 5½ inches for all concrete placed in curbs, gutters, and sidewalks.

When a high range water reducer is used, the maximum slump listed in 1, 2, 3, and 5
above, may be increased an additional 2 inches.

For self-consolidating concrete (SCC), the slump requirements specified above do not
apply, and are instead replaced by the target slump flow and slump flow range specified
as part of the SCC mix design.

Concrete Structures

6-02

6-02.3(4)D

Temperature and Time For Placement

Concrete temperatures shall remain between 55°F and 90°F while it is being placed,
except that Class 4000D concrete temperatures shall remain between 55°F and 75°F
during placement. The upper limit for placement for Class 4000D concrete may be
increased to a maximum of 80°F if allowed by the Engineer. Precast concrete that is
heat cured in accordance with

Section 6-02.3(25)D

shall remain between 50°F and 90°F

while being placed. The batch of concrete shall be discharged at the project site no more
than 1½ hours after the cement is added to the concrete mixture. The time to discharge
may be extended to 1¾ hours if the temperature of the concrete being placed is less
than 75°F. With the concurrence of the Engineer and as long as the temperature of the
concrete being placed is below 75°F, the maximum time to discharge may be extended
to 2 hours. When conditions are such that the concrete may experience an accelerated
initial set, the Engineer may require a shorter time to discharge. The time to discharge
may be extended upon written request from the Contractor. This time extension will be
considered on a case by case basis and requires the use of specific retardation admixtures
and the concurrence of the Engineer.

6-02.3(5) Acceptance of Concrete

6-02.3(5)A General

Concrete for the following applications will be accepted based on a Certificate of
Compliance to be provided by the supplier as described in

Section 6-02.3(5)B

1.  Lean concrete.
2.  Commercial concrete.
3.  Class 4000P concrete for Roadside Steel Sign Support Foundations.
4.  Class 4000P concrete for Type II, III, and CCTV Signal Standard Foundations that are

12’-0” or less in depth.

5. Class 4000P concrete for Type IV and V Strain Pole Foundations that are 12’-0” or

less in depth.

6. Class 4000P concrete for Steel Light Standard Foundations Types A & B.

Concrete Class EA will be accepted based on conformance to the requirements specified
in Section 6-02.3(2)C for proportioning, temperature, and 28 day compressive strength.

Slip-form barrier concrete will be accepted based on conformance to the requirements
for temperature, air content and compressive strength at 28 days for sublots as tested
and determined by the Contracting Agency. All other concrete will be accepted based on
conformance to the requirement for temperature, slump, air content for concrete placed
above finished ground line, and the specified compressive strength at 28 days for sublots
as tested and determined by the Contracting Agency.

A sublot is defined as the material represented by an individual strength test. An
individual strength test is the average compressive strength of cylinders from the same
sample of material.

Page 6-18

Concrete Structures

Each sublot will be deemed to have met the specified compressive strength requirement
when both of the following conditions are met:
1. Individual strength tests do not fall below the specified strength by more than

12½ percent or 500 psi, whichever is least.

2. An individual strength test averaged with the two preceding individual strength

tests meets or exceeds specified strength (for the same class and exact mix I.D. of
concrete on the same Contract).

When compressive strengths fail to satisfy one or both of the above requirements, the
Contractor may:
1. Request acceptance based on the Contractor/Suppliers strength test data for

cylinders made from the same truckload of concrete as the Contracting Agency
cylinders; provided:
a. The Contractor’s test results are obtained from testing cylinders fabricated,

handled, and stored for 28 days in accordance with FOP for AASHTO T 23 and
tested in accordance with AASHTO T 22. The test cylinders shall be the same
size cylinders as those cast by the Contracting Agency.

b. The technician fabricating the cylinders is qualified by either ACI, Grade 1 or

WAQTC to perform this Work.

c. The Laboratory performing the tests in accordance with AASHTO T 22 has

an equipment calibration/certification system, and a technician training and
evaluation process in accordance with AASHTO R-18.

d. Both the Contractor and Contracting Agency have at least 15 test results

from the same mix to compare. The Contractor’s results could be used if the
Contractor’s computed average of all their test results is within one standard
deviation of the Contracting Agency’s average test result. The computed
standard deviation of the Contractor’s results must also be within plus or minus
200 psi of the Contracting Agency’s standard deviation.

2. Request acceptance of in-place concrete strength based on core results. This

method will not be used if the Engineer determines coring would be harmful to the
integrity of the Structure. Cores, if allowed, will be obtained by the Contractor in
accordance with AASHTO T 24 and delivered to the Contracting Agency for testing
in accordance with AASHTO T 22. If the concrete in the Structure will be dry under
service conditions, the core will be air dried at a temperature of between 60°F and
80°F and at a relative humidity of less than 60 percent for 7 days before testing, and
will be tested air dry.

Acceptance for each sublot by the core method requires that the average compressive
strength of three cores be at least 85 percent of the specified strength with no one core
less than 75 percent of the specified strength. When the Contractor requests strength
analysis by coring, the results obtained will be accepted by both parties as conclusive and
supersede all other strength data for the concrete sublot.

Concrete Structures

6-02

If the Contractor elects to core, cores shall be obtained no later than 50 days after initial
concrete placement. The Engineer will concur in the locations to be cored. Repair of cored
areas shall be the responsibility of the Contractor. The cost incurred in coring and testing
these cores, including repair of core locations, shall be borne by the Contractor.

6-02.3(5)B

Certification of Compliance

The concrete producer shall provide a Certificate of Compliance for each truckload of
concrete. The Certificate of Compliance shall verify that the delivered concrete is in
compliance with the mix design and shall include:

Manufacturer plant (batching facility)
Contracting Agency Contract number
Date
Time batched
Truck No.
Initial revolution counter reading
Quantity (quantity batched this load)
Type of concrete by class and producer design mix number
Cement producer, type, and Mill Certification No. (The mill test number as required
by

Section 9-01.3

is the basis for acceptance of cement.)

Fly ash (if used) brand and Class
Accepted aggregate gradation designation

Mix design weight per cubic yard and actual batched weights for:
Cement

Fly ash (if used)
Coarse concrete aggregate and moisture content (each size)
Fine concrete aggregate and moisture content
Water (including free moisture in aggregates)
Admixtures brand and total quantity batched

Air-entraining admixture
Water-reducing admixture
Other admixture

For concretes that use combined aggregate gradation, the Certificate of Compliance
shall include the aggregate components and moisture contents for each size in lieu of
the aggregate information described above.

In lieu of providing a machine produced record containing all of the above information,
the concrete producer may use the Contracting Agency-provided printed forms, which
shall be completed for each load of concrete delivered to the project.

For commercial concrete, the Certificate of Compliance shall include, as a minimum, the
batching facility, date, and quantity batched per load.

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Concrete Structures

6-02.3(5)C

Conformance to Mix Design

Cement, coarse and fine aggregate weights shall be within the following tolerances of the
mix design:

Batch Volumes less than or

equal to 4 cubic yards

Batch Volumes more than 4 cubic yards

Cement

+5%

-1%

Cement

+5%

-1%

Aggregate

+10%

-2%

Aggregate

+2%

-2%

If the total cementitious material weight is made up of different components, these
component weights shall be within the following tolerances:
1. Cement weight plus 5 percent or minus 1 percent of that specified in the mix design.
2. Fly ash and ground granulated blast furnace slag weight plus or minus 5 percent of

that specified in the mix design.

3. Microsilica weight plus or minus 10 percent of that specified in the mix design.

Water shall not exceed the maximum water specified in the mix design.

6-02.3(5)D

Test Methods

Acceptance testing will be performed by the Contracting Agency in accordance
with the WSDOT

Materials Manual

M 46-01. The test methods to be used with this

Specification are:
AASHTO T 22

Compressive Strength of Cylindrical Concrete Specimens

FOP for AASHTO T 23

Making and Curing Concrete Test Specimens in the Field

FOP for AASHTO T 119

Slump of Hydraulic Cement Concrete

FOP for WAQTC TM 2

Sampling Freshly Mixed Concrete

FOP for AASHTO T 152

Air Content of Freshly Mixed Concrete by the Pressure
Method

FOP for AASHTO T 231

Capping Cylindrical Concrete Specimens

FOP for AASHTO T 309

Temperature of Freshly Mixed Portland Cement Concrete

ASTM C1611

Standard Test Method for Slump Flow of Self-Consolidating
Concrete (Inverted Mold Method only)

ASTM C1621

Standard Test Method for Passing Ability of Self-
Consolidating Concrete by J-Ring (Inverted Mold
Method only)

Concrete Structures

6-02

6-02.3(5)E

Point of Acceptance

Determination of concrete properties for acceptance will be made based on samples
taken as follows:

Bridge decks, overlays, bridge approach slabs, and barriers at the discharge of the
placement system. All other placements at the truck discharge.

It shall be the Contractor’s responsibility to provide adequate and representative samples
of the fresh concrete to a location designated by the Engineer for the testing of concrete
properties and making of cylinder specimens. Samples shall be provided as directed
in Sections

1-06.1

and

1-06.2

. Once the Contractor has turned over the concrete for

acceptance testing, no more mix adjustment will be allowed. The concrete will either be
accepted or rejected.

6-02.3(5)F

Water/Cement Ratio Conformance

The actual water cement ratio shall be determined from the certified proportions of the
mix, adjusting for on the job additions. No water may be added after acceptance testing
or after placement has begun, except for concrete used in slip forming. For slip-formed
concrete, water may be added during placement but shall not exceed the maximum
water cement ratio in the mix design, and shall meet the requirements for consistency
as described in

Section 6-02.3(4)C

. If water is added, an air and temperature test shall

be taken prior to resuming placement to ensure that Specification conformance has
been maintained.

6-02.3(5)G

Sampling and Testing for Temperature, Consistency, and

Air Content

Concrete properties shall be determined from concrete as delivered to the project and
as accepted by the Contractor for placement. The Contracting Agency will perform
acceptance testing on all concrete for temperature and air content, if applicable. Concrete
that is not self-consolidating concrete will be tested for slump. The following additional
acceptance tests will be performed on self-consolidating concrete:
1.  Slump flow within the target slump flow range.
2.  J ring passing ability less than or equal to 1.5 inches.
3.  VSI less than or equal to 1.

Sampling and testing will be performed before concrete placement from the first load.
Concrete shall not be placed until all tests have been completed by the Engineer, and the
results indicate that the concrete is within acceptable limits. If the concrete is not within
acceptable limits, sampling and testing will continue before concrete placement for each
load until one load meets all of the applicable acceptance requirements. After one test
indicates that the concrete is within specified limits, the concrete may be placed and the
sampling and testing frequency may decrease to one for every 100 cubic yards. Sampling
shall be performed in accordance with FOP for WAQTC TM 2 and random samples shall

Page 6-22

Concrete Structures

be selected in accordance with WSDOT

T 716

. After the first acceptable load of concrete,

up to ½ cubic yard may be placed from subsequent loads to be tested prior to testing for
acceptance.

When the results for any subsequent acceptance test indicates that the concrete as
delivered and approved by the Contractor for placement does not conform to the
specified limits, the sampling and testing frequency will be resumed for each load.
Whenever one subsequent test indicates that the concrete is within the specified limits,
the random sampling and testing frequency of one for every 100 cubic yards may resume.

Sampling and testing for a placement of one class of concrete consisting of 50 cubic yards
or less will be as listed above, except that after one set of tests indicate that the concrete
is within specified limits, the remaining concrete to be placed may be accepted by visual
inspection.

6-02.3(5)H

Sampling and Testing for Compressive Strength and Initial Curing

Acceptance testing for compressive strength shall be conducted at the same frequency as
the acceptance tests for temperature, consistency, and air content.

The Contractor shall provide and maintain a sufficient number of cure boxes in
accordance with FOP for AASHTO T 23 for curing concrete cylinders. The cure boxes shall
be readily accessible and no more than 500 feet from the point of acceptance testing,
unless otherwise allowed by the Engineer. The Contractor shall also provide, maintain
and operate all necessary power sources and connections needed to operate the cure
boxes. The cure boxes shall be in-place and functioning at the specified temperature for
curing cylinders prior to concrete placement. Concrete cylinders shall be cured in the cure
boxes in accordance with FOP for AASHTO T 23. The cure boxes shall have working locks
and the Contractor shall provide the Engineer with one key to each of the locks. Once
concrete cylinders are placed in the cure box, the cure box shall not be disturbed until
the cylinders have been removed. The Contractor shall retain the cure box Temperature
Measuring Device log and provide it to the Engineer upon request.

The Contractor shall protect concrete cylinders in cure boxes from excessive vibration and
shock waves during the curing period in accordance with

Section 6-02.3(6)D

All cure box costs shall be incidental to the associated item of work.

6-02.3(5)I

Test Section for Cast-In-Place SCC

Unless otherwise approved by the Engineer, the Contractor shall construct a test section
of the element being constructed of cast-in-place SCC. The Contractor shall confirm,
through the SCC placement operation in the test section, the SCC flows the distance
required, completely filling the forms and encapsulating the reinforcement as required
without leaving voids and pockets and causing segregation of the SCC mix. The test
section forms, reinforcing steel and concrete placing operations shall be identical to those
to be used in the production elements.

Concrete Structures

6-02

For horizontal elements, the test section shall simulate the flow of concrete for the
maximum distance anticipated during production concrete placement. The depth and
width of the test section for horizontal element may be smaller than the actual depth and
width of the element to be cast. For vertical elements, the test section shall be a minimum
of 33-percent of the height of the tallest element to be constructed. The Contractor shall
submit Type 2 Working Drawings consisting of formwork and reinforcement details of the
test section and SCC placement procedures.

After removing the forms, the test section will be inspected for signs of honeycombs,
cracks, aggregate segregation, sedimentation, cold joints, and other surface and concrete
placement defects. If such defects are present, the Contractor shall revise the formwork
and SCC placement procedures as necessary to eliminate such defects.

Acceptance of the test section and the SCC mix design is contingent on acceptable visual
inspection, and a minimum of two 4-inch minimum diameter core samples taken from
the placement location and the furthest-most limits of the concrete as identified by the
Engineer. The number of core locations will be specified by the Engineer. The difference
in average unit weight of the locations represented by the core samples shall be less than
5-percent.

The Contractor shall use the same SCC placement procedures confirmed by the Engineer
accepted test section for casting the production members.

6-02.3(5)J Vacant
6-02.3(5)K

Rejecting Concrete

Rejection Without Testing – The Engineer, prior to sampling, may reject any batch or load
of concrete that appears defective in composition; such as cement content or aggregate
proportions. Rejected material shall not be incorporated in the Structure.

6-02.3(5)L

Concrete With Non-Conforming Strength

Concrete with cylinder compressive strengths (fc) that fail to meet acceptance level
requirements shall be evaluated for structural adequacy. If the material is found to be
adequate, payment shall be adjusted in accordance with the following formula:

Pay adjustment =

2(f’c – fc)(UP)(Q)

f’c

Where:

f’c

= Specified minimum compressive strength at 28 days.

= Compressive strength at 28 days as determined by AASHTO Test Methods.

= Unit Contract price per cubic yard for the class of concrete involved.

= Quantity of concrete represented by an acceptance test based on the required

frequency of testing.

Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10) - page 29