346STRUCTURAL PORTLAND CEMENT CONCRETE

346-1Description

Use a Department -approved concrete mix design composed of a mixture of portland cement, aggregate, water, admixtures, and supplementary cementitious materials . Deliver the portland cement concrete to the site of placement in a freshly mixed, unhardened state. Obtain concrete from a plant that is cur rently on the Department’s Production Facility Listing. Producers seeking inclusion on the list shall meet the requirements of Section 105. If the concrete production facility’s Quality Control (QC) Plan is suspended, the Contractor is solely responsible t o obtain the services of another concrete production facility with an accepted QC Plan or await the reacceptance of the concrete production facility’s QC Plan prior to the placement of any further concrete on the project. There will be no changes in the Co ntract Time because of the suspension, as described . Bear all delay costs and other costs associated with the concrete production facility’s QC Plan acceptance or reacceptance.

346-2Materials

346-2.1General: Meet the following requirements:

Coarse Aggr egate ................................ ............................ Section 901 Fine Aggregate* ................................ .............................. Section 902 Portland Cement and Blended Cement ........................... Section 921 Water ................................ ................................ ...............Section 923 Admixtures** ................................ ................................ ..Section 924 Supplementary Cementitious Materials .......................... Section 929 *Use only silica sand except as provided in 902 . **Use products listed on the Department’s Approved Product List ( APL). Do not use materials containing hard lumps, crusts , or frozen matter, or that is contaminated with materials exceeding the specified limits in the above listed Sections.

346-2.2Types of Cement: Unless a specific type of cement is designated in the Contract

Documents , use Type I, Type IL, Type IP, Type IT, Type IS, Type II, or Type III cement in all classes of concrete. Use Type IL, Type IT, or Type II for all mass concrete elements. Use only the types of cements designated for each environmental classification in structural concrete as shown in Table 346-1. A mix design for a more aggressive environment may be used in a less aggressive env ironmental condition.

335 FY 2023-24 Return to Table of Contents

Table 346-1 Cement Use by Environmental Classification Component Slightly Aggressive Environment Moderately Aggressive Environment Extremely Aggressive Environment (1) Bridge Superstructures Precast Superstructure and Prestressed Elements Type I or Type III Type I, Type IL, Type II, Type III, Type IP, or Type IS Type II, Type IL, Type III (2), Type IT or Ternary Blend Cast in Place Type I Type I, Type IL, Type II, Type IP, or Type IS Type II, Type IL, Type IT or Ternary Blend Bridge Substructures , Drainage Structures, and other Structures All Elements Type I or Type III Type I, Type IL, Type II, Type IP, or Type IS Type II, Type IL, Type IT or Ternary Blend Notes:

when the ambient temperature at the time of concrete placement is 60°F and below .

346-2.3Supplementary Cementitious Materials : Supplementary cementitious

materials (SCMs) are required in all classes of concrete specified in Table 346-3. Nonreinforced concrete Class I (Seal) and Class I (Pavement), are exempted, and Class II when used in slightly aggressive environments . The quantity of portland cement that is replaced with SCMs must be on an equal weight replacement basis of the total cementitious materials in accordance with Table 346-2. When using Type IP, IS or IT blended cements, the total quantity of SCMs, including the blended cement added separately at the concrete plant shall meet the requirements of Table 346-2. 346-2.3.1 Highly Reactive Pozzolans: Materials that have a very high degree of pozzolanic reactivity due to t heir very fine particle sizes, including silica fume, metakaolin and ultrafine fly ash. 346-2.3.2 Binary Concrete Mixes : Concrete mixes containing portland cement and one SCM. 346-2.3.3 Ternary Concrete Mixes : Concrete mixes containing portland cement and any two SCMs. 336 FY 2023-24 Return to Table of Contents

Table 346-2 Cementitious Materials Concrete Mix Proportions (%) (Environmental classification is extremely aggressive, unless otherwise noted) Application Portland Cement Fly Ash Type F Slag Highly Reactive Pozzolans (4 and 5) Silica Fume Metakaolin Ultra-Fine Fly Ash General Use 50-82 18-50 51-79 18-40 3-9 63-77 15-25 8-12 63-77 15-25 8-12 30-45 10-20 45-60 30-50 50-70 36-43 50-55 7-9 33-42 50-55 8-12 33-42 50-55 8-12 Precast / Prestressed 70-85 (1) 15-30 (1) 50-82 18-50 51-79 18-40 7-9 63-77 15-25 8-12 63-77 15-25 8-12 30-40 10-20 50-60 30-50 50-70 36-43 50-55 7-9 33-42 50-55 8-12 33-42 50-55 8-12 Drilled Shaft 50-82 18-50 38-42 58-62 30-40 10-20 50-60 Mass Concrete 50-82 (2) 18-50 (2) 50-65 (3) 35-50 (3) 66-78 15-25 7-9 63-77 15-25 8-12 63-77 15-25 8-12 30-40 10-20 50-60 30-50 50-70 36-43 50-55 7-9 33-42 50-55 8-12 33-42 50-55 8-12

by the Contract Documents . A minimum concrete Surface Resistivity (SR) value is not required.

346-2.4Aggregates: Produce all concrete using Size No. 57, 67 or 78 coarse aggregates

Use Size No. 8, and Size No. 89 alone, only when approved by the Engineer. 337 FY 2023-24 Return to Table of Contents

Use Size No. 4 or larger blended with smaller size coarse aggregate as two components. 346-2.4.1 Optimized Aggregate Gradation: Improve the aggregate packing density at the Contractor’s option, by adding an intermediate -size coarse aggregate in accordance with FM 5 -621 to produce combined aggregate gradation of fine, intermediate , and coarse aggregate sizes for the concrete mixes. 346-2.4.2 Lightweight fine aggregate (LWFA) for internal curing: At the Contractor’s option, use LWFA to reduce the early -age concrete cracking by replacing some of normal fine aggregate with saturated LWFA.

346-2.5Admixtures : Ensure admixtures are used in accordance with the manufacturer’s

recommend ations and meetin g the requirements of Section 9.2, Volume II of the Materials Manual.

346-3Classification of Concrete

346-3.1General: The classifications of concrete are designated as Class I (Seal), Class I

(Pavement), Class II, Class II (Bridge Deck), Class III, Class IV, Class IV (Drilled Shaft), Class V, Class VI, and Class VII. The 28-day specified minimum compressives trength, maximum water to cementitious materials ratio and target slump of each class are detailed in Table 346-3. The required air content for all classes of concrete is less than or equal to 6.0%. For purposes of this Specification the concrete is further classified as follows:

with a tolerance of ± 1.5 inches.

a tolerance of ± 1.5 inches when a Type F, G, I or II admixture is used .

1.5 inches. For Class I (Pavement), m eet the requirements of Section 350 .

concrete for cast-in-place applications . The target slump is 9 inches with a tolerance of ± 1.5 inches.

to use SCC for cast-in-place applications The minimum target slump flow is 22.5 inches with a tolerance of ± 2.5 inches.

346-3.2Concrete Class Substituti ons: The Engineer may allow the s ubstitution of a

higher class concrete in lieu of the specified class concrete when the substituted concrete mixes are included as part of the QC Plan, or for precast concrete, the Precast Concrete Producer QC Plan. The sub stituted higher class concrete must meet or exceed the requirements of the specified class concrete. When the average compressive strength is less than the specified minimum compressive strength of the higher class mix design, notify the Engineer. Acceptance is based on the requirements in Table 346-3 for the specified class concrete.

346-3.3Acceptance Requirements : The specified minimum 28 -day strengths,

maximum water to cementitious materials ratio (w/cm), and target slumps for each class of concrete are given in Table 346 -3. For lightweight concrete, acceptance requirements also include the hardened density specified in the Contract Documents . The calculation of the water to cementitious materials ratio (w/cm) is based on the total mass of cementiti ous materials including portland cement and any SCMs used in the mix.

338 FY 2023-24 Return to Table of Contents

Table 346-3 Compressive Strength, w/cm, and Slump of Concrete Classes Class of Concrete 28-day Specified Minimum Compressive Strength (f′c) (psi) Maximum Water to Cementitious Materials Ratio (pounds per pounds) Target Slump Value (inches) I (Seal) 3,000 0.53 8 I (Pavement) (1) 3,000 0.50 1.5 or 3 II (3) 3,400 0.53 3 (2) II (Bridge Deck) 4,500 0.44 3 (2) III 5,000 0.44 3 (2) IV 5,500 0.41(4) 3 (2) IV (Drilled Shaft) 4,000 0.41 8.5 V 6,500 0.37(4) 3 (2) VI 8,500 0.37(4) 3 (2) VII 10,000 0.37(4) 3 (2) Notes:

content will not apply. The maximum allowable slump is 6 inches, except as noted in (2). The Contractor is permitted to use concrete meeting the requirements of ASTM C478 (4,000 psi) in lieu of the specified Class II concrete for precast endwalls, inlets, manholes and junction boxes.

fly ash is used, the maximum water to cementitious material ratio will be 0.30.

346-3.4Acceptance of concrete at 56 days: Use concrete mix designs meeting the

specified compressive strength at 56 days at the Contractor’s option . Submit the request to the Engineer for approval. After the Engineer’s approval, notify the concrete producer to initiate the mix design approval process at least 90 days prior to th e anticipated concrete placement.

346-3.5Durability for Concrete Construction:

346-3.5.1 Minimum Cementitious Materials Content: Ensure that the produced concrete meets the minimum amount of cementitious materials content in Table 346-4. Table 346-4 Minimum Amount of Total Cementitious Materials Content (pounds per cubic yard of concrete) Concrete Class Environmental Classification Extremely Aggressive Moderately Aggressive Slightly Aggressive I (Seal) (1), I (Pavement) (1) , and II, 470

II (Bridge Deck), III (2) , IV, IV (Drilled

Shaft), V, VI and VII 600 550 510

Notes:

mix design must meet the requirements of Section 9.2 Volume II of the Materials Manual.

minimum cementitious materials content may be reduced to 470 pounds per cubic yard. 339FY 2023-24Return to Table of Contents

346-3.5.2 Chloride Content Limits: Use the following maximum allowable

chloride content limits for the concrete application and/or exposure environment shown:

Table 346-5

Chloride Content Limits for Concrete Construction

Application/Exposure Environment

Maximum Allowable

Chloride Content,

(pounds per cubic yard

of concrete)

Non-Reinforced Concrete No Test Needed

Reinforced Concrete Slightly Aggressive Environment 0.70

Moderately or Extremely Aggressive Environment 0.40

Prestressed Concrete 0.40

Suspend concrete placement immediately for every mix design if chloride

test results exceed the limits of Table 346-5 until corrective measures are made. Submit an

Engineering Analysis Scope in accordance with 6-4 by a Specialty Engineer knowledgeable in

the areas of corrosion and corrosion control, to determine if the material meets the intended

service life of the structure on all concrete produced from the mix design failing chloride test

results to the previous passing test results.

346-3.5.3 Surface Resistivity Test: Ensure that the concrete meets or exceeds a

Sr value of 29 kΩcm at 28 days or 56 days if specified, when a highly reactive pozzolan is

specified in the Contract Documents.

346-4Special Types of Concrete

346-4.1Drilled Shaft Concrete: Notify the Engineer at least 48 hours before placing

drilled shaft concrete. Obtain slump loss test results demonstrating that the drilled shaft concrete

maintains a slump of at least 5 inches throughout the concrete elapsed time before drilled shaft

concrete operations begin.

Perform the slump loss test at the anticipated ambient temperature for drilled shaft

placements greater than 30 cubic yards and an elapsed time of greater than five hours.

Obtain slump loss test results from an approved laboratory or from a field

demonstration. Slump loss test results for drilled shafts requiring 30 cubic yards of concrete or

less and a maximum elapsed time of five hours or less may be done in a laboratory. Obtain all

other slump loss test results in the field.

The concrete elapsed time is defined in Section 455. Obtain the Engineer’s

approval for use of slump loss test results including elapsed time before concrete placement

begins.

Test each load of concrete for slump to ensure that it is within the limits of this

Section. Initially cure acceptance cylinders for 48 hours before transporting them to the

laboratory.

If the elapsed time during placement exceeds the slump loss test data, submit an

Engineering Analysis Scope in accordance with 6-4 by a Specialty Engineer knowledgeable in

concrete foundations, to determine if the shaft is structurally sound and free from voids. At the

direction of the Engineer, excavate the drilled shaft for inspection. Obtain approval from the

Engineer before placing any additional shafts. 340FY 2023-24Return to Table of Contents

346-4.2Mass Concrete: When the Contract Documents designate any structure as mass

concrete, use a Specialty Engineer to develop and administer a Mass Concrete Control Plan

(MCCP). Develop the MCCP in accordance with Section 9.4 Volume II of the Materials Manual.

Provide the Specialty Engineer a list of all concrete elements identified. Use a sequential

identification code for each element indicating the bridge or structure number, location and type

of element, least dimension size, and environmental exposure.

Record core and differential temperatures for all structures included in the MCCP

and monitor only the elements specified therein. Ensure that the concrete core temperatures do

not exceed the maximum allowable temperature of 180°F and that the differential temperatures

between the element core and surface do not exceed the maximum allowable temperature

differential of 35°F. Submit the MCCP to the Engineer for approval at least 21 calendar days

prior to the first anticipated mass concrete placement.

Do not place concrete until the proposed MCCP has been approved. Any

modifications must be submitted as addenda to the original MCCP and must be approved in

writing by the Engineer.

Install temperature measuring sensors and recording devices for all mass concrete

elements in accordance with the MCCP. Do not add local additional insulation or external

sources of heat around the surface sensors that affect the temperature readings.

Ensure that, prior to the first concrete placement of each concrete element the

Specialty Engineer or approved designee personally inspects the installation of the temperature

measuring devices and verifies that the temperature data acquisition equipment is properly

functioning. The Specialty Engineer shall be available for immediate consultation during the

monitoring period of any mass concrete element.

Use temperature data acquisition equipment to record temperature readings in

accordance with the MCCP.

Within three workings days of the completion of temperature recording for each

concrete element, submit the Mass Concrete Field Report in accordance with Section 9.4,

Volume II of the Materials Manual.

For a group of elements, the Engineer may approve a monitoring reduction if the

first element placed does not exceed either the maximum temperature or maximum temperature

differential. Request written approval from the Engineer at least 14 calendar days prior to the

anticipated date of the intended reduced monitoring. If approved, monitoring of the recorded

temperatures is not required for the remaining elements meeting all of the following

requirements:

measures (if used).

within minus 10°F of the ambient temperature during placement of the initial element.

monitored element and keep them in place for at least the same length of time as for the initial

element.

Resume monitoring of the temperatures for all elements if directed by the

Engineer. 341FY 2023-24Return to Table of Contents

Instrumentation and temperature monitoring are not required for miscellaneous

drilled shafts supporting sign, signal, lighting or Intelligent Transportation System (ITS)

structures when the as built diameter is six feet or less, and the total cementitious materials

content of the concrete mix design is less than or equal to 752 pounds per cubic yard.

Monitoring of the recorded temperatures is not required for any mass concrete

substructure element meeting all of the following requirements:

feet or less.

72 hours following the completion of concrete placement.

aggressive or moderately aggressive.

requirements of 346-2.3.

less than or equal to 752 pounds per cubic yard.

Implement immediate corrective action as directed by the Specialty Engineer

when either the core temperature or the temperature differential of any mass concrete element

exceeds its maximum allowable value. The approval of the MCCP shall be revoked.

Submit an Engineering Analysis Scope in accordance with 6-4 for approval,

which addresses the structural integrity and durability of any mass concrete element that is not

cast in compliance with the approved MCCP, or which exceeds the allowable core temperature

or temperature differential.

Submit all analyses and test results requested by the Engineer for any

noncompliant mass concrete element. Submit a revised MCCP and do not place any mass

concrete elements until a revised MCCP has been approved in writing by the Engineer.

The Department will not provide compensation for additional costs or loss of time

due to additional analyses, tests, or other impacts on production caused by not monitoring the

recorded temperatures.

346-4.3Flowing Concrete and Self-Consolidating Concrete (SCC): Use Flowing

concrete or SCC when shown in the Contract Documents or to facilitate concrete placement in

structures of complex geometric shape or highly reinforcement.

Perform a field demonstration mockup using an approved mix design. Submit the

mockup design to the Engineer for approval including the location of the sawcut.

Cast a partial or full-scale mockup(s) and demonstrate through the successful

production the ability to produce and place flowing concrete or SCC.

The design, production, and evaluation product must meet the following

requirements:

curing methods, such as the use of ready-mix trucks, pumps, chutes, hopper, consolidation

equipment, etc. The mockup shall contain reinforcing steel, mass concrete cooling pipes if

required during construction, and other embedded items typical of the cast element.

time. 342FY 2023-24Return to Table of Contents

in the Contract Documents.

demonstration.

mockup requires concrete from multiple concrete plants, the concrete from each plant must be

represented in the mockup.

honeycombing, and rock pockets, mix segregation, and other inclusions developed during

placement of the concrete.

FM 5-617.

beginning of concrete placement operations.

Based on the inspection results of the field demonstration mockup, the acceptance

of using flowing concrete or SCC in the structural element or section of the element is at the

Engineer’s discretion.

The required mockup demonstration may be omitted at the Contractor’s request.

Submit documentation indicating successful experience of furnishing and placing flowing

concrete or SCC on similar Department projects. Such documentation must list projects by date

of completion, name or project reference number, structural elements or type of unit placed,

quantity of concrete furnished, names and experience of personnel, and contact information for

verification.

346-4.4Lightweight Concrete: Submit the fresh and hardened concrete density for mix

design approval. The hardened density is the equilibrium density in ASTM C567. Ensure that the

hardened density of the mix design is within ± 2 lb/ft of the hardened density specified in the

Contract Documents.

During production, the freshly mixed concrete density must be within ± 3 lb/ft of

the approved mix design fresh density.

346-5Sampling and Testing Methods

Perform concrete sampling and testing in accordance with the following methods:

Table 346-7

Concrete Sampling and Testing Methods

Description Method

Slump of Hydraulic Cement Concrete ASTM C143

Air Content of Freshly Mixed Concrete by the Pressure Method (1) ASTM C231

Air Content of Freshly Mixed Concrete by the Volumetric Method (1) ASTM C173

Making and Curing Test Specimens in the Field (2) ASTM C31

Compressive Strength of Cylindrical Concrete Specimens (3) ASTM C39

Obtaining and Testing Drilled Core and Sawed Beams of Concrete ASTM C42

Density of Structural Lightweight Concrete ASTM C567

Initial Sampling of Concrete from Revolving Drum Truck Mixers or Agitators FM 5-501 343FY 2023-24Return to Table of Contents

Table 346-7

Concrete Sampling and Testing Methods

Description Method

Low Levels of Chloride in Concrete and Raw Materials FM 5-516

Density (Unit Weight), Yield and Air Content (Gravimetric) of Concrete ASTM C138

Temperature of Freshly Mixed Portland Cement Concrete ASTM C1064

Sampling Freshly Mixed Concrete (4) ASTM C172

Static Segregation of Self-Consolidating Concrete using Column Techniques ASTM C1610

Slump Flow of Self-Consolidating Concrete ASTM C1611

Relative Viscosity of Self-Consolidating Concrete ASTM C1611

Visual Stability Index of Self-Consolidating Concrete ASTM C1611

Passing Ability of Self-Consolidating Concrete by J-Ring ASTM C1621

Rapid Assessment of Static Segregation Resistance of Self-Consolidating

Concrete Using Penetration Test ASTM C1712

Aggregate Distribution of Hardened Self-Consolidating Concrete FM 5-617

Hardened Visual Stability Index of Self-Consolidating Concrete AASHTO R 81

Fabricating Test Specimens with Self-Consolidating Concrete ASTM C1758

Concrete Resistivity as an Electrical Indicator of its Permeability AASHTO T 358

meters, use an aggregate correction factor determined by the concrete producer for each mix design to be tested. Record and

certify test results for correction factors for each type of aggregate at the concrete production facility.

initial curing. Cylinders will be delivered to the testing laboratory in their molds. The laboratory will remove the specimens from

the molds and begin final curing.

the density.

portions, as described in ASTM C172.

346-6Quality Control

346-6.1General: Perform QC activities to ensure materials, methods, techniques,

personnel, procedures and processes utilized during production meet the specified requirements.

For precast/prestressed concrete operations, ensure that the QC testing is performed by the

producer.

Accept the responsibility for QC inspections on all phases of work. Ensure all

materials and workmanship incorporated into the project meet the requirements of the Contract

Documents.

346-6.2Concrete Mix Design: Provide concrete that has been produced in accordance

with a Department approved mix design, in a uniform mass free from balls and lumps.

For slump target values in excess of 6 inches, including flowing concrete and

SCC, utilize a grate over the conveyance equipment to capture any lumps or balls that may be

present in the mix. The grate must cover the entire opening of the conveyance equipment and

have an opening that is a maximum of 2-1/2 inches in any one direction. Remove the lumps and

balls from the grate and discard them. Discharge the concrete in a manner satisfactory to the

Engineer. Perform demonstration batches to ensure complete and thorough placements in

complex elements, when requested by the Engineer.

Do not place concretes of different compositions such that the plastic concretes

may combine, except where the Plans require concrete with a surface resistivity value of 344FY 2023-24Return to Table of Contents

29 kΩcm or below and one with higher than 29 kΩ-cm values in a continuous placement.

Produce these concretes using separate mix designs. For example, designate the mix with

calcium nitrite as the original mix and the mix without calcium nitrite as the redesigned mix.

Ensure that both mixes contain the same cement, fly ash or slag, coarse and fine aggregates and

admixtures. Submit both mixes for approval as separate mix designs, both meeting all

requirements of this Section. Ensure that the redesigned mix exhibits plastic and hardened

qualities which are additionally approved by the Engineer as suitable for placement with the

original mix. The Engineer will approve the redesigned mix for commingling with the original

mix and for a specific project application only. Alternately, place a construction joint at the

location of the change in concretes as approved by the Engineer.

346-6.3Delivery Certification: Ensure that an electronic delivery ticket is furnished

with each batch of concrete before unloading at the placement site. The delivery ticket may be

proprietary software or in the form of an electronic spreadsheet, but shall be printed. Ensure that

the materials and quantities incorporated into the batch of concrete are printed on the delivery

ticket. Include the following information on the delivery ticket:

Items (3) through (6) do not apply to non-agitating concrete transporting vehicles.

Ensure the batcher responsible for production of the batch of concrete signs the

delivery ticket, certifying the batch of concrete was produced in accordance with the Contract

Documents.

Sign the delivery ticket certifying that the design mix maximum specified water to

cementitious materials ratio was not exceeded due to any jobsite adjustments to the batch of

concrete, and that the batch of concrete was delivered and placed in accordance with the Contract

Documents.

346-6.4Plastic Property Tolerances: Reject concrete with slump or air content that

does not fall within the specified tolerances, except as noted below, and immediately notify the

concrete production facility that an adjustment of the concrete mixture is required.

If a load does not fall within the tolerances, test each subsequent load and the first

adjusted load. If failing concrete is not rejected or adjustments are not implemented, the Engineer

may reject the concrete and terminate further production until the corrections are implemented.

At the Contractor’s risk, water may be added at the placement site immediately

after completion of the initial slump or slump flow test, either to correct a low slump or slump

flow, or to increase the concrete workability, provided the addition of water does not exceed the

water to cementitious materials ratio as defined by the mix design.

After adding water at the placement site depending on the type of concrete,

perform the following tests:

the slump tolerance range. If the slump is outside the tolerance range, reject the load.

segregation resistance. Do not reject SCC exceeding the high-end slump flow tolerance if it has

passed the rapid assessment of static segregation resistance test. Reject the load if the slump flow 345FY 2023-24Return to Table of Contents

is below the low-end tolerance. As an exception, the Engineer may accept the concrete if the

rejection compromises the structural integrity of the element or produces other detrimental

effects. Minimum vibration may be needed in accordance with Section 400.

If an adjustment is made at the concrete production facility, perform a slump test

on the next load to ensure the concrete is within the slump tolerance ranges.

Except for SCC, do not place concrete represented by slump test results outside of

the tolerance range. Include water missing from the water storage tanks upon arrival at the

project site in the jobsite water added.

Do not allow concrete to remain in a transporting vehicle to reduce slump.

346-7Mixing and Delivering Concrete

346-7.1General Requirements: Operate all concrete mixers at speeds and volumes per

the manufacturer’s design or recommendation as stipulated on the mixer rating plate.

346-7.2Transit Truck Mixing: Produce a completely uniform mixed concrete in a truck

mixer for a minimum of 70 revolutions at the mixing speed designated by the truck

manufacturer.

` Prior to starting the discharge of the concrete at the jobsite, when water is added,

record the added quantity and mix the concrete 30 additional drum mixing revolutions. Do not

make more than two mix adjustments. Seek approval from the Engineer prior to using a central

mixer and depositing the batch into a truck mixer.

346-7.2.1 Transit Time: Ensure compliance with Table 346-8 between the initial

introduction of water into the mix and completely discharging all the concrete from the truck.

Reject concrete exceeding the maximum transit time. The Engineer may approve an extension of

the transit time which will be identified on the approved mix design.

Table 346-8

Maximum Allowable Transit Time

Non-Agitator Trucks Agitator Trucks

45 minutes 60 minutes

75 minutes (1) 90 minutes (1)

Note:

346-7.2.2 Placement Time: All the concrete in a load must be in its final

placement position a maximum of 15 minutes after the transit time or cutoff time has expired

unless a time extension is approved by the Engineer. As an exception, the Engineer may accept

concrete that exceeds the transit time or cutoff time if the load passes the slump or slump flow

tests. Place concrete in continuous manner in accordance with Section 400.

For Class IV (Drilled Shaft) mixes, placement time may be extended

provided the slump loss time of the first concrete placed is not exceeded throughout the elapsed

time.

The Engineer may perform Independent Verification (IV) testing to verify

the plastic and hardened properties of the concrete when a time extension is granted.

346-7.3On-site Batching and Mixing: Use a mixer of sufficient capacity to prevent

delays that may be detrimental to the quality of the work. Ensure that the accuracy of batching

equipment is in accordance with requirements of this Section. 346FY 2023-24Return to Table of Contents

346-7.4Concreting in Cold Weather: Do not mix or place concrete when the air

temperature is below 40ºF. Protect the fresh concrete from freezing in accordance with

concrete mixing and placement operations occurring in a temperature controlled environment.

346-7.5Concreting in Hot Weather: Hot weather concreting is defined as the

production, placing and curing of concrete when the concrete temperature at placing exceeds

85ºF but is 100ºF or less.

Unless the specified hot weather concreting measures are in effect, reject concrete

exceeding 85ºF at the time of placement. Regardless of special measures taken, reject concrete

exceeding 100ºF. Predict the concrete temperatures at placement time and implement hot

weather measures to avoid production shutdown.

346-7.6Sample Location: Obtain acceptance samples from the point of final placement

Where concrete buckets are used to discharge concrete directly to the point of

final placement or into the hopper of a tremie pipe, samples will be obtained from the discharge

of the bucket. When the concrete is discharged directly from the mixer into the bucket and the

bucket is discharged within 20 minutes, samples may be obtained from the discharge of the

mixer.

Where conveyor belts, troughs, pumps, or chutes are used to transport concrete

directly to the point of final placement or into the hopper of a tremie pipe, samples will be

obtained from the discharge end of the entire conveyor belt, trough, pump, or chute system.

Where concrete is placed in a drilled shaft or other element using a tremie pipe

and a concrete pump, samples will be obtained from the discharge of the pump line at the

location of the tremie hopper.

For all other placement methods, prior to each placement, obtain Department

approval for sampling at the discharge of the mixer in lieu of sampling at the point of final

placement. Submit the sampling correlation procedure to the Engineer for approval prior to the

placement of the concrete. Once the comparative sampling correlation is approved by the

Engineer, apply this correlation to the plastic properties tolerances for samples obtained from the

discharge of mixer.

Where a concrete pump is used to deposit concrete directly into a drilled shaft

which is a wet excavation without the use of a tremie, or other applications as approved by the

Engineer, ensure the discharge end of the pump line remains immersed in the concrete at all

times after starting concrete placement.

346-8Plastic Concrete Sampling and Testing

QC tests include air content, temperature, slump, and preparing cylinders for testing at

later dates with the following exceptions:

with the following exceptions:

For Class I (Pavement), the air content testing is not required.

For Lightweight concrete, tests also include the plastic density (unit weight).

For SCC, QC tests also include slump flow in lieu of slump, visual stability index, and

rapid assessment of static segregation.

In addition, calculate the water to cementitious materials ratio in accordance with

FM 5-501 for compliance to the approved mix design.

Ensure that each truck has a rating plate and a valid mixer identification card issued by

the Department. Ensure that the revolution counter on the mixer is working properly, and

calibration of the water dispenser has been performed within the last twelve months. Reject any 347FY 2023-24Return to Table of Contents

concrete batches that are delivered in trucks that do not have mixer identification cards. Remove

the mixer identification card when a truck mixer is discovered to be in noncompliance and the

mixer deficiencies cannot be repaired immediately. When the mixer identification card is

removed for noncompliance, make note of the deficiency or deficiencies found, and forward the

card to the District Materials and Research Engineer who has Producer QC Plan acceptance

authority.

Perform plastic concrete tests on the initial delivery from each plant of each concrete

design mix each day. Ensure QC technicians meeting the requirements of Section 105 are present

and performing tests throughout the placement operation. Ensure a technician is present and

performing tests throughout the placement operation at each placement site. If a project has

multiple concrete placements at the same time, identify the technicians in the QC Plan to ensure

minimum sampling and testing frequencies are met. Ensure that the equipment used for delivery,

placement and finishing meets the requirements of this Specification.

When a truck designated for QC testing arrives at the discharge site, a subsequent truck

may also discharge once a representative sample has been collected from the QC truck and while

awaiting the results of QC testing. Reject non-complying loads at the jobsite. Ensure that

corrections are made on subsequent loads. Immediately cease concrete discharge of all trucks if

the QC truck has failing test. Perform plastic properties tests of concrete on all trucks prior to the

first corrected truck and the corrected truck. When more than one truck is discharging into a

pump simultaneously, only the truck designated for QC testing may discharge into the pump to

obtain a representative sample of concrete from the QC truck only.

Furnish sufficient concrete of each design mix as required by the Engineer for

verification (VT) testing. When the Engineer’s VT test results do not compare with the QC

plastic properties test results, within the limits defined by the Independent Assurance (IA)

checklist comparison criteria, located in Materials Manual Chapter 5, disposition of the concrete

will be at the option of the Contractor.

On concrete placements consisting of only one load of concrete, perform initial sampling

and testing in accordance with this Section. The acceptance sample and plastic properties tests

may be taken from the initial portion of the load.

If any of the QC plastic properties tests fail, reject the remainder of that load, and any

other loads that have begun discharging, terminate the LOT and notify the Engineer. Make

cylinders representing that LOT from the same sample of concrete.

Following termination of a LOT, obtain samples from a new load, and perform plastic

properties tests until the water to cementitious materials ratio, air content, temperature and slump

comply with the Specification requirements. Initiate a new LOT once the testing indicates

compliance with Specification requirements.

Suspend production when any five loads in two days of production of the same design

mix are outside the specified tolerances. Increase the frequency of QC testing to one per load to

bring the concrete within allowable tolerances. After production resumes, obtain the Engineer’s

approval before returning to the normal frequency of QC testing.

If concrete placement stops for more than 90 minutes, perform initial plastic properties

testing on the next batch and continue the LOT. Cylinders cast for that LOT will represent the

entire LOT.

When the Department performs Independent Verification (IV), the Contractor may

perform the same tests on the concrete at the same time. The Department will compare results

based on the Independent Assurance (IA) Checklist tolerances. 348FY 2023-24Return to Table of Contents

346-9Acceptance Sampling and Testing

346-9.1General: Perform plastic properties tests in accordance with 346-8 and cast a set

of three QC cylinders, for all structural concrete incorporated into the project. Take these

acceptance samples randomly as determined by a random number generator acceptable to the

Department. The Department will independently perform VT plastic properties tests and cast a

set of VT cylinders. The VT cylinders will be the same size cylinder selected by the Contractor,

from a separate sample from the same load of concrete as the Contractor’s QC sample.

For each set of QC cylinders verified by the Department, cast two additional

cylinders from the same sample, and identify them as the quality control resolution (QR) test

cylinders. The Department will also cast two additional verification resolution (VR) test

cylinders from each VT sample. All cylinders will be clearly identified as outlined in the

Sample/LOT Numbering System instructions located on the State Materials Office website.

Deliver the QC samples, including the QR cylinders to the final curing facility in accordance

with ASTM C31. Concurrently, the Department will deliver the VT samples, including the VR

cylinders, to their final curing facility.

Test the QC laboratory cured samples for compressive strength at the age of

28 days, in a laboratory meeting and maintaining at all times the qualification requirements listed

in Section 105.

Ensure the QC testing laboratory input the compressive strength test results into

the Department’s Materials Acceptance and Certification (MAC) system within 24 hours after

testing. Notify the Engineer when results cannot be inputted into MAC.

The Department will compare the VT sample compressive strength test results

with the corresponding QC sample test results.

346-9.2Sampling Frequency: As a minimum, sample and test concrete of each mix

design for water to cementitious materials ratio, air content, temperature, slump and compressive

strength once per LOT as defined by Table 346-9. The Engineer will randomly verify one of

every four consecutive LOTs of each mix design based on a random number generator. The

Department may perform Independent Verification (IV) testing to verify compliance with

specification requirements. All QC activities, calculations, and inspections will be randomly

confirmed by the Department.

Table 346-9

Sampling Frequency

Class Concrete (1) LOT Size

I (Seal) Each seal placement

I (Pavement) According to Section 350

II, II (Bridge Deck), III, IV, V, VI, VII 50 cubic yards, or one day’s production, whichever is

less

IV (Drilled Shaft) 50 cubic yards, or one day’s production, whichever is

less (2)

production, whichever is less.

beginning of the next drilled shaft placement. 349FY 2023-24Return to Table of Contents

346-9.2.1 Reduced Frequency for Acceptance Tests: Except for Class I

(Pavement), the LOT size may represent 100 cubic yards when produced with the same mix

design at the same concrete production facility for the same prime Contractor and subcontractor

on a given Contract. As an exception, the requirements for the precast/prestressed production

facility will only include the same mix design at the same concrete production facility. The

reduced testing frequency of Class I (Pavement) is described in the Section 350.

Submit strength test results indicating that the two following criteria are

met:

or greater than the specified minimum compressive strength (f′c) plus 2.33 standard deviations

minus:

exceeds the f′c plus 1.34 standard deviations.

Base calculations on a minimum of ten consecutive strength test results for

a Class IV or higher; or a minimum of five consecutive strength results for a Class III or lower.

The average of the consecutive compressive strength test results, based on

the class of concrete, can be established using historical data from a previous Department

project. The tests from the previous Department project must be within the last calendar year or

may also be established by a succession of samples on the current project. Only one sample can

be taken from each LOT. Test data must be from a laboratory meeting the requirements of

Section 105. Obtain Department approval before beginning reduced frequency LOTs.

If at any time a strength test is not verified or the average strength of the

previous ten or five consecutive samples based on the class of concrete from the same mix

design and the same production facility does not conform to the above conditions, return to the

frequency represented by the LOT as defined in Table 346-9. Notify the Engineer that the initial

frequency is reinstated. In order to reinitiate reduced frequency, submit a new set of strength test

results.

346-9.3Strength Test Definition: The strength test of a LOT is defined as the average

compressive strength tests of at least two companion cylinders cast from the same sample of

concrete and tested at the same age.

346-9.4Acceptance of Concrete: The Engineer will accept the concrete of a given LOT

when the compressive strength test results are verified and meets the minimum specified

compressive strength in Table 346-3. Ensure that the hardened concrete strength test results are

obtained in accordance with 346-9.3.

The process of concrete compressive strength verification and acceptance consists

of the following steps:

Do not discard a cylinder strength test result based on low strength (strength

below the specified minimum strength as per the provisions of this Section).

When one of the three QC cylinders from a LOT is lost, missing, damaged or

destroyed, determination of compressive strength will be made by averaging the remaining two

cylinders. If more than one QC cylinder from a LOT is lost, missing, damaged or destroyed, the 350FY 2023-24Return to Table of Contents

Contractor will core the structure at no additional expense to the Department to determine the

compressive strength. Prior to coring, obtain Engineer’s approval for coring the structure and its

proposed coring location. Acceptance of LOT may be based on VT data at the discretion of the

Engineer.

For each QC and each QR cylinder that is lost, missing, damaged or destroyed,

payment for that LOT will be reduced by $750.00 per 1,000 psi of the specified design strength

[Example: loss of two Class IV (Drill Shaft) QC cylinders that has no VT data will require the

element to be cored and a pay reduction will be assessed (4,000 psi / 1,000 psi) x $750 x 2 =

$6,000]. This reduction will be in addition to any pay adjustment for low strength.

346-9.4.1 Small Quantities of Concrete: When a project has a total plan quantity

of less than 50 cubic yards, that concrete will be accepted based on the satisfactory compressive

strength of the QC cylinders. Submit certification to the Engineer that the concrete was batched

and placed in accordance with the Contract Documents. Submit a QC Plan for the concrete

placement operation in accordance with Section 105. The Engineer may perform IV testing as

identified in 346-9 and evaluate the concrete in accordance with 346-9.7.

346-9.5Verification: The results of properly conducted test by QC and VT laboratories

on specimens prepared from the same sample of concrete are not to differ by more than 14%.

Difference (%) = ABS ( QC−VT

QC ) 100

Where:

Difference (%) is the absolute percentage difference between QC

and VT average compressive strength.

The procedure consists of verifying if the QC and VT compressive strengths data

meet the established comparison criteria:

and the average compressive strength of VT is less than or equal to 14%, the QC test results are

upheld and verified. The Engineer will accept at full pay only LOTs of concrete represented by

plastic property results which meet the requirements of the approved mix design and strength test

results which equal or exceed the respective specified minimum strength.

and the average compressive strength of VT data exceeds 14%, the compressive strength results

are not verified and the Engineer will initiate the resolution procedure.

Maintain the QR and VR cylinders for a minimum of 30 days following the

testing date of the specified strength.

346-9.6Resolution: The Engineer will perform the resolution process to identify the

reliability of the compressive strength results when the difference between the average

compressive strength of QC and the average compressive strength of VT data exceeds 14% as

described in 346-9.5(2).

The Engineer will estimate the 28-day strengths (VR28 and QR28) for the VR and

QR cylinders using the following equation:

Estimated 28-Day Compressive Strength (psi) = ( Average Strength at (t) days

-17.8 + 46.3[ln (t)] − 3.3[ln (t)] ) 100

Where: 351FY 2023-24Return to Table of Contents

cylinders testing.

ln (t) is the natural logarithm of (t).

The Engineer will compare:

Comparison results must not be greater than 17.5%. Core samples of the hardened

concrete may be required.

V D (%) = ABS ( VT − VR

VT ) 100

Q D (%) = ABS ( QC − QR

QC ) 100

Where:

VD (%) is the absolute percentage difference between VT and VR28.

QD (%) is the absolute percentage difference between QC and QR28.

Perform the resolution with the concrete compressive strength data at 56 days in

lieu of the 28 days when the acceptance of concrete is at 56 days.

The resolution procedure will use the above equations. The Engineer will

determine through the resolution procedure whether the QC strength test results or the VT

strength test are deemed to be the most accurate, LOTs will then be considered to be verified.

The Engineer will inform the QC and VT laboratories within three calendar days

of the acceptance compressive strength test to transport their QR and VR cylinders to the

resolution laboratory. The QC and VT laboratories will transport their own hold cylinders to the

resolution testing laboratory within three calendar days after the Engineer notifies the Contractor

that a resolution procedure is required. In addition, the Engineer will ensure that the QR and VR

cylinders are tested within 14 calendar days of the acceptance strength tests.

The Engineer will determine the most accurate strength test result to represent the

four or fewer consecutive LOTs as follows:

deemed accurate and the QC strength will represent the LOTs. The Department will pay for cost

of the resolution testing.

the QC strength is deemed as most accurate and will represent the LOTs. The Department will

pay for the cost of the resolution testing.

the VT strength is deemed as most accurate and will represent the LOTs. The Department will

assess a $1,000 pay reduction for the cost of the Resolution Investigation.

Engineer, with input from the DMO, will determine if any Department IA evaluations are

required and which test results are most accurate. The Department will pay for the cost of the

resolution testing.

When the Engineer cannot determine which strength test results are the most

accurate, the concrete represented by the four consecutive LOTs will be evaluated based on the

QC data. 352FY 2023-24Return to Table of Contents

The results of the resolution procedure will be forwarded to the Contractor within

five working days after completion of the investigation.

346-9.7Structural Adequacy: The Engineer will evaluate the structural adequacy for

verified concrete that does not meet the minimum specified compressive strength of Table 346-3.

For structural adequacy, with standard molded and cured compressive strength

cylinders, the compressive strength of concrete is satisfactory provided that the two following

criteria are met:

minimum compressive strength by more than:

to or less than 5,000 psi.

specified minimum compressive strength is greater than 5,000 psi.

to or exceeds the specified minimum compressive strength. This condition only applies if there

are two or more previous LOTs to calculate the average.

The Engineer will consider the concrete for a given LOT as structurally adequate

and coring will not be allowed when a concrete compressive strength test result falls below the

specified minimum strength but has met the above conditions.

346-9.7.1 Lightweight concrete: The Engineer may require an Engineering

Analysis Scope in accordance with 6-4 to establish structural and durability adequacy when the

lightweight concrete plastic density (unit weight) is outside of the specified tolerances.

346-10Investigation of Low Compressive Strength Concrete

When a verified concrete compressive strength test result falls below the specified

minimum strength, and does not meet the structural adequacy described in 346-9.7, perform one

of the following options:

structural and durability adequacy. When the scope is approved by the Engineer, submit an

Engineering Analysis Report (EAR) in accordance with 6-4 that includes a full structural

analysis. If the results of the structural analysis indicate adequate strength to serve its intended

purpose with adequate durability, and is approved by the Engineer, the Contractor may leave the

concrete in place subject to the requirements of 346-11, otherwise, remove and replace the LOT

of concrete in question at no additional expense to the Department.

Section to determine the in-place strength of the LOT of concrete in question, at no additional

expense to the Department. The Engineer will determine whether to allow coring of the in-place

concrete or require an engineering analysis based on the compressive strength of the test

cylinders.

346-10.1Coring for Determination of Structural Adequacy: Core strength test results

obtained from the structure will be accepted by both the Contractor and the Department as the in-

place strength of the LOT of concrete in question. The core strength test results will be used in

lieu of the cylinder strength test results for determination of structural adequacy. The Department

will calculate the strength value to be the average of the compressive strengths of the three

individual cores. This will be accepted as the actual measured value.

Obtain and test the cores in accordance with ASTM C42.The Engineer will select

the size and location of the drilled cores so that the structure is not impaired and does not sustain 353FY 2023-24Return to Table of Contents

permanent damage after repairing the core holes. Obtain the Engineer’s written approval before

taking any concrete core sample. Notify the Engineer 48 hours prior to taking core samples.

Sample three undamaged cores taken from the same approximate location where

the questionable concrete is represented by the low strength concrete test cylinders. Repair core

holes after samples are taken with a product in compliance with Section 930 or 934 and meeting

the approval of the Engineer. Report the test results to the Engineer within two calendar days of

testing the core samples.

The Engineer, with input from the DMO, will consider the concrete as structurally

adequate, in the area represented by core tests at the actual test age, if the average compressive

strength of cores does not fall below the specified minimum compressive strength (f′c) by more

than:

The Engineer may also require the Contractor to perform additional testing as

necessary to determine structural adequacy of the concrete.

346-11Pay Adjustments for Low Compressive Strength Concrete

346-11.1General: For any LOT of concrete failing to meet the f′c as defined in 346-3,

346-9, and satisfactorily meeting all other requirements of the Contract Documents, including

structural adequacy, the Engineer will individually reduce the price of each low strength LOT in

accordance with this Section.

346-11.2Basis for Pay Adjustments: The Engineer will determine payment reductions

based on the 28-day compressive strength, represented by either acceptance compressive strength

or correlated cores strength test results based on the following criteria:

minimum compressive strength, but no more than the limits established in 346-9.7 below the

specified minimum strength, do not core hardened concrete for determining pay adjustments.

Use the acceptance compressive strength test results.

minimum compressive strength by more than the limits established in 346-9.7, the structure may

be cored for determination of structural adequacy as directed by the Engineer. Use the result of

the 28-day correlated core compressive strength or the acceptance compressive strength test,

whichever is less.

A price adjustment will be applied to the certified invoice price the Contractor

paid for the concrete or the precast product.

The Engineer will relate the strength at the actual test age to the 28-day strength

for the design mix represented by the cores using appropriate strength time correlation equations.

In precast concrete operations, excluding prestressed concrete, ensure that the

producer submits acceptable core sample test results to the Engineer. The producer may elect to

use the products in accordance with this Section. Otherwise, replace the concrete in question at

no additional cost to the Department. For prestressed concrete, core sample testing is not allowed

for pay adjustment. The results of the cylinder strength tests will be used to determine material

acceptance and pay adjustment.

346-11.3Calculating Pay Adjustments: The Engineer will determine payment

reductions for low strength concrete accepted by the Department. The 28-day strength is

represented by either cylinders or correlated cores strength test results in accordance with

346-11.2. 354FY 2023-24Return to Table of Contents

Reduction in Pay is equal to the reduction in percentage of concrete compressive

strength below the specified minimum strength:

Reduction in Pay (%) = ( f ′ c−28 day Strength

f ′ c ) 100

For the elements that payments are based on the per foot basis, the Engineer will

adjust the price reduction from cubic yards basis to per foot basis, determine the total linear feet

of the elements that are affected by low strength concrete samples and apply the adjusted price

reduction accordingly.

Use the concrete compressive strength data at 56 days in lieu of the 28 days when

the acceptance of concrete is at 56 days.

346-12Pay Reduction for Plastic Properties

A rejected load in accordance with 346-6.4 is defined as the entire quantity of concrete

contained within a single ready-mix truck or other single delivery vehicle regardless of what

percentage of the load was placed. If concrete fails a plastic properties test and is thereby a

rejected load but its placement continues after completion of a plastic properties test having a

failing result, payment for the concrete will be reduced.

The pay reduction for cast-in-place concrete will be twice the certified invoice price per

cubic yard of the quantity of concrete in the rejected load.

The pay reduction for placing a rejected load of concrete into a precast product will be

applied to that percentage of the precast product that is composed of the concrete in the rejected

load. The percentage will be converted to a reduction factor which is a numerical value greater

than zero but not greater than one. The precast product payment reduction will be twice the

Contractor’s billed price from the producer for the precast product multiplied by the reduction

factor.

If the Engineer authorizes placement of the concrete, even though plastic properties

require rejection, there will be no pay reduction based on plastic properties failures; however,

any other pay reductions will apply. 355FY 2023-24Return to Table of Contents

PORTLAND CEMENT CONCRETE - CLASS NS

347-1Description

The requirements of this Section are applicable to concrete designated as nonstructural portland cement concrete, ( Class NS) hereinafter referred to as concrete. Use concrete composed of a mixture of portland cement, aggregates, water ; and where specified chemical admixtures, or supplementary cementitious materials. Deliver concrete to placement site in a freshly mixed, unhardened state. Ensure the concrete is placed and cured in a manner to ensure that the strength and durability of the concrete is maintained.

347-2Materials

347-2.1General: Certify that all materials used in concrete are from Department

approved sources, and free from detrimental matter. Meet the following requirements: Portland Cement ................................ ......Section 921 Coarse Aggregate* ................................ ..Section 901 Fine Aggregate* ................................ ......Section 902 Water ................................ ....................... Section 923 Chemical Admixtures ............................. Section 924 Supplementary Cementitious Materials ..Section 929 * Recycled Asphalt Pavement (RAP) may replace up to 20% of the total aggregate in the design mix. Use RAP from a Department approved stockpile.

347-3Production, Mixing and Delivery

347-3.1Concrete Production Requirements: Obtain concrete from a plant that i s

currently on the Department’s Nonstructural Concrete Production Facility Listing. Producers seeking inclusion on the list must contact the local District Materials Office for approval. When Volumetric Mixers are used, deliver concrete in accordance wit h the Volumetric Mixer Standards of the Volumetric Mixer Manufacture rs Bureau (VMMB ) VMMB 100-01. Substitution of structural concrete in lieu of non -structural concrete may be used if approved by the Engineer. If structural concrete is used in lieu of n on-structural concrete, obtain the concrete from a production facility meeting the requirements of Section 346. Acceptance is based on the requirements of Section 347. The Engineer may disqualify any concrete production facility for non -compliance with Specification requirements.

347-3.2Delivery: The maximum allowable mixing, agitation, and placement time of

concrete is 120 minutes.

347-3.3Small Quantities of Concrete: With approval of the Engineer, small quantities

of concrete, less than 3 cubic yards placed in one day and less than 0.5 cubic yards placed in a single placement may be accepted using a pre -bagged mixture.

347-4Certification and Acceptance

347-4.1General: Furnish a delivery ticket with each batch of concrete before

discharging concrete at the placement site. Ensure the delivery ticket includes material quantities 356 FY 2023-24 Return to Table of Contents