551Hydraulic Cement Concrete

551.01DESCRIPTION

These are the general requirements for designing hydraulic cement concrete mixtures, the ingredients, mixing, transporting, placing, curing, testing and acceptance for all classes and uses of hydraulic cement concrete.

551.02MATERIALS

Provide cementitious materials and admixtures from sources listed on the QPL.

.1 Cement

Furnish low-alkali hydraulic cement meeting the following requirements as specified in the contract. Use cements meeting A or B unless otherwise specified.

IP, IS or IT. When fly ash or ground granulated blast furnace slag (GGBFS) is used in blended cement, limit the replacement amount to the maximums specified in Subsection

551.03.2(A)(5)

HS, MH, or LH. Meet the following requirements for all types of cement:

sodium oxide (NaO) plus 0.658 times the percentage of potassium oxide (K 2O).

from the Project Manager. Different brands or grades, if approved, cannot be used alternately in any 1 placement.

.2 Fly Ash

When included in the mix design, furnish fly ash in accordance AASHTO M 295, Class C or F, including optional chemical requirements as set forth in Table 2.

.3 Ground Granulated Blast Furnace Slag (GGBFS)

When included in the mix design, furnish GGBFS in accordance with AASHTO M 302, Grade 100, or Grade 120.

.4 Microsilica Fume (Silica Fume)

When included in the mix design, furnish microsilica in accordance with AASHTO M 307.

.5 Admixtures

When included in the mix design, furnish admixtures in accordance with AASHTO M 194. Ensure that the total contribution of chlorideions from all admixtures and air-entraining agents does not exceed 50 parts per million chlorideions (Cl-) by weight of cementitious material. All admixtures must be compatible with other constituents including cement, silica fume, GGBFS, fly ash, and other admixtures. Dose all chemical admixtures according to manufacturer’s recommendations unless trial batches provide adequate information for different dosage rates.

.6 Air-entraining Agents

Include an air-entraining agent in the mix design unless otherwise specified. Furnish an air- entraining agent in accordance with AASHTO M 154. – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1

.7 Water

Furnish water for mixing and curing concrete in accordance with Subsection 713.01.

.8 Aggregate

Furnish aggregates from an approved source in accordance with Subsection 701.01.

.9 Storage of Materials

other approved storage. Provide storage facilities that permit convenient sampling and inspection. Store all sacked cementitious materials in weatherproof buildings or, if approved, in the open on raised platforms with waterproof covering. Partially set, caked or lumpy cementitious material will be rejected.

the different aggregate sizes to prevent contamination and segregation. Suspend work until aggregate contamination or segregation is corrected. Build up aggregate stockpiles in a manner that avoids contamination and segregation. Re-mix segregated aggregate to the grading requirements at Contractor expense. When ready-mixed concrete is furnished, the ready-mix producer’s stockpiled aggregates must meet all aggregate specifications. Establish separate stockpiles for Department work if existing stockpiles do not meet specifications. Do not use contaminated or segregated aggregate removed from stockpiles in the work. Handle all aggregates to prevent segregation and to obtain uniformity of materials. Pile separated aggregates and aggregates secured from different sources in separate stockpiles. Provide sites which are level, firm and free of all foreign materials for the stockpiles. If aggregates are placed directly on the ground, do not use material within 6 inches (150 mm) of the ground level. Leave this material undisturbed to avoid contaminating the aggregate being used with the foreign material.

CONSTRUCTION REQUIREMENTS

.1 Classification

Design and produce concrete using the classifications defined in Table 551-1 . 2020 EDITION V5.1 HYDRAULIC CEMENT CONCRETE – 551 TABLE 551-1 CONCRETE CLASSIFICATION Class Use General General use concrete. Used for sidewalks, curbs, and slope protectors. Also used in precast products. Structure Used for structural concrete. (Use for all sub-structural work.) Deck Used for all superstructure concrete, deck slabs and barriers. Overlay Used on bridge deck overlays. Pave Used for concrete pavement, streets, and highways. PRE Used in all prestressed items. Controlled Low Strength Material (CLSM) Used for bedding, encasement, and general backfill. (flowable fill, density fill, flowable mortar, slurry cement backfill.) Drilled Shaft Used for drilled shafts. SCC (Self-consolidating concrete) Used for precast, drilled shafts, and aesthetic structural components. Lean Used for setting metal fence posts and braces and similar uses where high quality concrete is not necessary.

.2 Composition of Concrete

Design and produce concrete in accordance with Table 551-2. – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1 2020 EDITION V5.1 HYDRAULIC CEMENT CONCRETE – 551 Furnish the names of proposed suppliers and locations of proposed aggregate sources upon notice of award. New sources must be sampled, tested, and approved. Coordinate with the Project Manager for submitting samples for testing.

Meet all the requirements of MT 100.

stated below for specific classes of concrete. State the design proportions in terms of aggregates in a saturated, surface dry condition. Submit the proposed aggregate source and proportion computations. Submit a final mix design for approval at least 15 business days before intended use on form MDT-MAT-008.

replacement for hydraulic cement in the mix design.

cementitious material. Combinations of various classes of fly ash may not exceed 30% by weight of the total cementitious material.

total cementitious material when a minimum of 15% fly ash or GGBFS is also included in the mix design or when the mix design incorporates acceptable blended cement.

cementitious material.

50% by weight of the total cementitious material. When multiple SCMs are used in a design, the total replacement rate may not exceed 50% by weight of the total cementitious material. Calculate the W/C ratio as the total weight of water divided by the total weight of cementitious material.

may be used in the mix design.

mixtures tested in accordance with ASTM C1012 may be submitted for approval. Acceptance will be based on expansion less than 0.10% at 18 months.

that would otherwise not be allowed. The following provisions may be included in the mix design:

long haul or other project conditions. When delayed set is included in the mix design, the time requirements for placing the concrete in final position in accordance with Subsection 551.03.4 may be replaced by time to final placement requirements included in the mix design. Include in the mix design information on the delayed set provisions of the design and specific time to final placement requirements. Support the time to final placement with test results from trial batches. – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1

cementitious materials or other admixtures that result in slow strength gain or permeability reduction. When included in the mix design, testing at 56 days may be requested. Support this request with test results from trial batches. Upon acceptance, 56-day results will be used in all provisions that refer to 28- day strength, and permeability will be accepted in accordance with Table 551-8.

and include in the mix design flexural strength results of at least 500 psi (3.5 MPa) in accordance with AASHTO T 97.

in accordance with Table 551-2 and the following: • Use 3%-5% silica fume. Include fly ash and/or GGBFS as SCMs. • SCMs replacement quantities must meet the requirements of Subsection 551.03.2(A)(5). • Do not use incompatible air entraining, water reducing and/or super-plasticizing admixtures. • Mix requires trial batch surface resistivity test results in accordance with AASHTO T 358 greater than 15 kilohm-centimeters at 28 days or 21 kilohm- centimeters at 56 days. Rapid chloride permeability test results in accordance with AASHTO T 277 less than 3300 coulombs at 28 days or 2000 coulombs at 56 days will also be accepted. • Submit a batching sequence procedure with the mix design including the amount of material charged and the time before the next material will be added. Include approximate mixer revolutions for each stage of the sequence. • The target strength to be used for incentive calculations is the 28/56-day strength submitted with the mix design. If the mix design strength is greater than 5,500 psi, the target will equal 5,500 psi. • When barrier rail is cast with Class Deck concrete, the lower range for the W/C ratio may be reduced to 0.38. Submit the request for approval with the mix design. Alternative mix designs not in accordance with Table 551-2 may be accepted provided the following requirements are met:

3, 7, and 28 days. The design must produce strengths in accordance with Table 551-2 by the specified age.

maximum allowed shrinkage for mix design acceptance is .0300% at 28 days.

greater than 15 kilohm-centimeters at 28 days.

ASTM C469.

point-count method at 100x magnification. The average of all tests must not exceed 0.009 inches (0.230 mm) with no single test greater than 0.010 inches (0.260 mm). The total air content must exceed 5.5%. 2020 EDITION V5.1 HYDRAULIC CEMENT CONCRETE – 551

material charged and the time before the next material will be added. Include approximate mixer revolutions for each stage of the sequence.

submitted with the mix design. If the mix design strength is greater than 5,500 psi, the target will equal 5,500 psi.

through dense reinforcement and adequately fill voids without segregation or excessive bleeding without the need for vibration. Drilled shaft concrete should not begin initial set until the placement is complete. Design and produce Class Drilled Shaft concrete in accordance with Table 551-2 and the following:

than 8 inches (200 mm). Do not place drilled shaft concrete having a slump of less than 7 inches (175 mm).

st batch of concrete for a shaft to the anticipated completion of that shaft. All concrete used for the drilled shaft must maintain a minimum of a 6-inch (150 mm) slump until 2 hours after the estimated completion.

or achieve certain placement properties

meet the above requirements and those of Subsection 551.03.2(G) .

concrete in accordance with the following requirements:

(123.8 L/m 3). Use a latex admixture containing a polymer of 66% ± 5% styrene and 34% ± 5% butadiene, with the polymer comprising between 46% and 49% of the total emulsion. The emulsion must have a sodium alkyl sulfate stabilizer acting as an anionic surfactant, polymer average particle size between 1,900 and 2,500 angstroms, a weight of 8.43 to 8.52 pounds per gallon (1.01 - 1.02 kg/L) at 75 °F (24 °C), and a pH between 9.5 and 11.0.

(29 °C) at all times. Provide a thermometer capable of storing minimum and maximum temperatures and place it with any admixture stored on site. Replace admixture subjected to temperatures outside the range above at no expense to the Department.

SCMs, aggregate, natural sands, silty sands, air entraining admixture and water. CLSM contains a low cementitious content for reduced strength development. Submit a mix design for approval including aggregate gradations, cement and SCM mill certifications, proportioning, and trial batch information.

following requirements:

determined by ASTM D4832. – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1

by ASTM D6103

nominal maximum aggregate size designs.)

the following requirements:

ASTM D4832

by ASTM D6103. Do not use materials in CLSM with a plasticity index over 4 according to AASHTO T 89 and AASHTO T90. Furnish aggregates in accordance with Table 551-3 or Table 701-2 TABLE 551-3 CLSM GRADATIONS Percentage By Weight Passing Square Mesh Sieves Sieve Size Percent Passing ¾-inch (19 mm) 100 No. 4 (4.75 mm) 65 - 100 No. 30 (0.600 mm) 15 - 80 No. 200 (0.075 mm) 0 - 30 High air generators or foaming agents may be used in lieu of conventional air entraining admixtures and may be added at the jobsite and mixed in accordance with the manufacturer’s recommendation. The requirements for percent air and unit weight are for laboratory mix designs only and are not intended for jobsite acceptance requirements. Produce a consistent mix that results in a flowable product at the time of placement which does not require manual means to move it into place. Secure tanks, pipes, and other members to be encased in CLSM to prevent displacement during placement. Protect CLSM from traffic until sufficient strength has been achieved for further construction operations. The CLSM may be mixed onsite, or at a ready-mix plant and transported to the site. Keep the mix homogeneous and in a suspended condition to prevent settling of the materials prior to placement. Characteristics of CLSM include consistency, workability, and plasticity such that the material is flowable, self-compacting and self-consolidating during placement.

through densely reinforced or complex structural elements under its own weight and adequately fill voids without segregation or excessive bleeding without the need for vibration. 2020 EDITION V5.1 HYDRAULIC CEMENT CONCRETE – 551 SCC may be used for Classes General (in precast or aesthetic placements only), Structure, and Drilled Shaft concrete. Design and produce SCC in accordance with Table 551-2 and the following:

specified or established in the contract (e.g., Class Drilled Shaft = 4000 psi (28 MPa)). Many precast designs requiring Class General concrete have varying design strengths.

the range of 20 to 26 inches (450 to 710 mm). Test in accordance with AASHTO T 347. When used for a drilled shaft design, include in the design, hourly slump-flow retention testing up to the desired placement time of the shaft.

AASHTO T 351.

345. When used for a drilled shaft, include in the design, hourly J-ring testing up to the desired placement time of the shaft. Include the above test results in the mix design submittal. If SCC is used in the production of precast items, meet the testing requirements in Subsection 554.03.6 .

with Table 551-2. Alternative mix designs not in accordance with Table 551-2 may be accepted provided the following requirements are met.

22 for 3, 7, and 28 days. The 28-day results must exceed specified strength.

maximum allowed shrinkage for mix design acceptance is .0350% at 28 days.

modified point-count method at 100x magnification. The average of all tests must not exceed 0.009-inch (230 μm) with no single test greater than 0.010-inch (260 μm). The total air content must exceed 5.5%.

551-2. Alternative mix designs not in accordance with Table 551-2 may be accepted provided the following requirements are met.

3, 7, and 28 days. Also include strength tests at intended de-tensioning/release times (e.g., 12 hrs., 16 hrs., 24 hrs., etc.) The 28-day results must exceed specified strength.

contain a product data sheet proving the product meets the specifications required for its intended use. Prepackaged concrete is subject to Project Manager approval.

Table 551-2 . Submit material proportioning for acceptance. A mix design in accordance with MT 100 is not required for Class Lean concrete. – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1

.3 Batching, Mixing, Handling and Sampling

Produce each class of specified concrete from approved material batched in the proportions specified in the approved mix design. Correct for moisture content variations. All concrete aggregates are sampled using methods described in MT 201 using sample sizes used in MT 202. MT 122 will be used to calculate combined gradations. The water may be proportioned by weight or volume. Proportion the cement and aggregates by weight. The temperature of the combined material must be less than 130 °F (54 °C) before the addition of cementitious materials. Meet the requirements of ASTM C94 for all concrete batch plants and operations prior to and throughout production of concrete for any work, including concrete for any field trial batches. In addition to ASTM C94, meet the following requirements throughout the production of concrete:

including each plant’s quality control procedures, calibration records, maintenance records, and any other information pertinent to proper concrete production. All measuring devices, batching equipment, trucks, and mixers are subject to approval.

by pressure variations in the water supply lines. The Project Manager may require an auxiliary tank for filling the weighing tank.

device, accurate to within plus or minus 1.0% of the required volume or plus or minus 1 gallon (3.8 L), whichever is less. Completely discharge wash water from the mixer before starting any batching operation.

concrete.

the true weight.

admixture separately to prevent interaction of the different admixtures before mixing with other batch materials. Agitate admixtures to ensure homogeneous concentrations in accordance with the manufacturer’s recommendations. If using a mechanical dispenser for proportioning admixtures, provide a site gauge or meter. Ensure unobstructed flow and accurate dosing of admixtures. Batch admixtures in accordance with ASTM C94.

Ensure equipment for weighing aggregates is accurate to within 0.5% of the true weight. Weigh aggregates to within 2% of the batch target weight. 2020 EDITION V5.1 HYDRAULIC CEMENT CONCRETE – 551 Weigh each size of aggregate separately.

with ASTM C94. Include on the ticket any water or admixture added after the record is printed and the initials of the person making the additions. Approval is required before any addition to the mix after batching and initial mixing has been completed.

admixtures within the specified time to form a uniformly mixed mass. Meet the requirements of ASTM C94. Operate mixers following the manufacturer’s recommendations. The Department may require uniformity testing. When required, meet the requirements of Subsection 106.04 . Do not place concrete improperly or inadequately mixed in the work. If incorporated, remove the concrete at no cost to the Department. Do not mix, transport, or place concrete using equipment with aluminum or aluminum parts that contact the concrete. Produce concrete in such quantity and at such a rate as proper placement and finishing will permit. Do not re-temper partially set concrete. Do not use mixed concrete that has remained in the truck mixer drum longer than 10 minutes without agitation. When silica fume is incorporated in the mix design, the maximum mixer revolutions will be waived. Ensure a minimum of 50 revolutions at mixing speed when the concrete is in a low-slump stage [2 to 3 inches (50 to 75 mm)] to properly disperse silica fume particles.

admixtures is permitted up to 2 times. Do not re-dose with other admixtures without the approval of the Project Manager. On-site dosing of water or admixture in no way relieves the contractor of producing passing plastic and hardened concrete test results.

The addition of water is allowed only 1 time and a minimum of 30 revolutions at mixing speed are required before discharge of concrete. Do not add water if part of the batch has been discharged as a W/C ratio cannot be determined. Do not add water if the slump is within specified range.

otherwise approved in the mix design stage. Only admixtures included in the approved mix design may be dosed on-site. A minimum of 30 revolutions at mixing speed are required before discharge of concrete. Do not add admixtures if any concrete has been discharged from the mixer other than the minimal amount for initial testing. When the measured plastic air content or slump exceeds the upper test limit and there is time available within the discharge time limit specified, rotate the load at agitation speed and re-test the air content and/or slump. Do not use additives to reduce the air content and/or slump. No other materials may be added to the concrete mixture. – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1

.4 Transporting Concrete

Ensure that the capacity of the plant and transportation equipment provides a delivery rate to permit handling, placing, and finishing of the work. Time the delivery of loads to prevent the in-place concrete from taking initial set before succeeding layers or lifts are placed. Do not permit any layer or lift of concrete to remain exposed in excess of 20 minutes before being covered by fresh concrete. Document the method and time of delivery by batch tickets issued to the driver and signed by the Inspector at the plant if present. Deliver the ticket to the Inspector upon arriving at the project. Meet the requirements of ASTM C94 and the following:

within 1½ hours after introducing the mixing water and cement. If long hauls or other project conditions are expected, meet the requirements of Subsection 551.03.2(A)(8)(a). When the ambient temperature is 85 °F (29 °C) or above, place the concrete in final position within 1 hour after the water and cement are introduced.

equipment to transport concrete except when placing concrete pavement in accordance with Section 501 .

.5 Placing Concrete

Place concrete in accordance with Sections 501, 552, and 553. Place Class Deck concrete, and Class Structure concrete if used within bridge decks, with a temperature between 50 and 80 °F (10 and 26 °C). Place all other classes of concrete with a temperature between 50 and 85 °F (10 and 29 °C). Always place concrete as near as possible to its final position. Do not place concrete that has taken initial set. Do not place concrete:

members, or construction joints.

water is sufficient to effect or damage surface mortar quality, cause a flow, or wash the concrete surface.

reinforcing in it; or

strength. Ensure all reinforcement and other embedded items are clean and free from dried mortar, rust, scale, oil, or foreign matter before placing concrete. Remove all sawdust, chips, other construction debris and extraneous matter from the interior of forms before placing concrete. Treat the forms interior surfaces to prevent mortar adhesion. Moisten all foundations, forms, and contacting concrete surfaces with water just before the concrete is placed. Remove any standing water on surfaces which will contact the concrete. 2020 EDITION V5.1 HYDRAULIC CEMENT CONCRETE – 551 Provide a method of concrete placement that has a consistent, minimal impact on the concrete properties. All equipment proposed for use in mixing, conveying, placing, and compacting the concrete is subject to Project Manager approval prior to its use. All the necessary equipment for any particular placement must be on site and proven to be in working condition before the placement commences. Ensure the equipment is well maintained, suitable in kind and adequate in capacity for the work. Support bars to maintain their position as shown in the contract. Place and secure all reinforcing, dowels, and other embedded items as specified. Deposit concrete in small quantities at many points and then work or run it along the forms. Carefully fill each part of the forms, depositing the concrete as close as possible to its final position, working the coarse aggregates back from the face and forcing the concrete under and around the reinforcing bars. Deposit concrete around steel shapes and closely spaced reinforcing bars, on 1 side of the steel, uniformly working it until the concrete flushes under the steel to the opposite side before any concrete is placed on the opposite side or over the steel. Place concrete with means as to avoid segregation of the materials and the displacement of the reinforcement. Remove and discard any concrete that is segregated, is too wet for use, or is not of uniform consistency. Deposit concrete through an approved means when placement operations involve a free drop of concrete by more than 5 feet (1.5 m) to prevent segregation. Place concrete in a continuous operation between expansion or construction joints. Do not add water to the surface of concrete before or during finishing. Thoroughly clean all chutes, troughs, and pipes after each run. Discharge any flushing water away from the forms and in place concrete. Once the concrete has taken initial set, avoid jarring the forms or straining the projecting reinforcement ends.

deposit. Regulate the discharge.

the first placement of each day, visually inspect the pump’s water chamber for water leakage. Do not use a pump that allows free water to flow past the piston. If a concrete pump is used as the placing system, discard the pump priming slurry before placement. Eliminating the priming slurry from the concrete may require that several cubic yards of concrete are discharged through the pumping system and discarded. Use of a concrete pump requires a written plan to place the remaining concrete if the pump breaks down. Provide a pump that produces a continuous flow of concrete without air pockets. Arrange equipment so that the impact on the plastic air content of the concrete is affected as little as possible, and that the freshly placed concrete is not damaged by any form of vibration. If boom angles will vary significantly, furnish means to control air content variation.

st placement of each day, visually inspect the conveyor to ensure proper operation. Provide a belt free of tears and holes and operates smooth and free of bouncing and – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1 jarring to prevent segregation of the concrete. Protect the concrete while on the conveyor to prevent the concrete’s plastic properties from changing. Do not use a conveyor exceeding 200 feet (60 m). Equip all conveyors with a drop-chute and scraper to prevent segregation and mortar loss respectively. Once concrete placement begins, ensure that there is proper and equal edge- distance between the edge of the belt and windrow of concrete.

the first placement of each day, visually inspect the bucket for proper working condition and contaminants. The bucket should be clean and free of hardened concrete and excess of release agent. Once concrete has been discharged into the bucket, do not place concrete back into a mixer to be altered or remixed.

after depositing into the work. Consolidate the concrete by mechanical vibration subject to the following:

by the vibrator manufacturer.

slump over a minimum 18-inch (455 mm) radius.

form corners and angles.

and remove the vibrators from the concrete. Vibrate to thoroughly consolidate the concrete without causing segregation or forming localized grout areas.

which the vibration is visible.

sections or layers of concrete. Do not use vibrators to transport concrete in the forms. Use plastic or rubber tipped vibrator heads when placing concrete near epoxy coated reinforcing steel.

concrete along form surfaces, in corners and locations impractical to reach with the vibrators. Refer to Section 501 for consolidation requirements for concrete paving.

.6 Weather and Temperature Limitations

Concreting during hot or cold weather requires an approved written plan to be implemented upon abrupt changes in weather conditions or equipment failures. When required, use Omega HH309A four channel data logging thermometers.

moisture loss or rate of cement hydration of freshly mixed concrete. Do not place Classes Deck or Overlay concrete in temperatures exceeding 95 °F (35 °C). Other classes of concrete may be placed in temperatures exceeding 95 °F (35 °C) with Project Manager approval. 2020 EDITION V5.1 HYDRAULIC CEMENT CONCRETE – 551 When hot weather concreting is anticipated, submit a hot weather concreting plan for review and approval. Include detailed procedures, including production, placement, finishing, curing and protection of concrete during hot weather concreting. Do not place concrete when the ambient temperature is 85 °F (29 °C) and rising and/or the evaporation rate is greater than 0.2 lb./ft2/hr. (1 kg/m2/h) without an approved hot weather concreting plan. Do not place Classes Deck or Overlay without an approved plan when the ambient temperature is greater than 80 °F (27 °C) and/or when the evaporation rate is greater than 0.15 lb./ft 2/hr. (0.75 kg/m2/h). When hot weather as defined above exists, monitor site conditions (air temperature, humidity, wind speed) to assess the need for evaporation control measures beginning no later than 1 hour before the start of concrete placing operations. Continue to monitor site conditions at intervals of 30 minutes or less until specified curing procedures have been applied.

discharge will not exceed the specified maximum allowable concrete temperature. Acceptable production methods to reduce the temperature of the concrete include shading aggregate stockpiles, sprinkling water on coarse aggregate stockpiles; using chilled water for concrete production; substituting chipped or shaved iced for portions of the mixing water; and cooling concrete materials using liquid nitrogen. Include in the submittals for hot weather concreting which methods will be used and in what order they will be initiated when multiple methods are to be used. The substitution of other cooling methods will be considered by the Department when requested in the submittal and accompanied by satisfactory supporting data.

will come in contact with the plastic concrete below 85 °F (29 °C). Include methods and equipment that will be used to keep the plastic concrete from cracking (e.g., fogging equipment, burlap, plastic, curing compounds, etc.). Describe devices or procedures that will be used to monitor wind speed, temperature, humidity, and other weather variables determining evaporation rate. Also include a detailed description of curing practices that will be used to supplement standard requirements in hot weather placements. Protect the concrete against thermal shrinkage cracking due to rapid drops in concrete temperature greater than 40 °F (22 °C) during the first 48 hours unless otherwise specified. Under hot weather conditions, scheduling placements at other-than-normal hours may be advisable. Concrete showing evidence of plastic shrinkage cracking or thermal cracking will be removed and replaced at no cost to the Department.

temperatures below 35 °F (2 °C) at any time during the specified curing and protection period following concrete placement. Assume all risk for placing concrete during cold weather. Replace frozen or damaged concrete at Contractor expense. Remove ice, snow, and frost from the forms, subgrade, adjacent concrete, and reinforcing bars before placing concrete. Do not place concrete on frozen base or subgrade. When cold weather concreting is anticipated, submit a cold weather concreting plan for review and approval. Include detailed procedures for production, transportation, placement, curing, and temperature monitoring of the concrete during cold weather. – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1 Submit the plan a minimum of 15 calendar days prior to any concrete which is scheduled to be placed during cold weather. Prepare and submit a separate cold weather concreting plan for each concrete component which requires different methods of protection from cold weather. Clearly indicate which concrete components are covered by each submittal.

weather concreting plans:

methods to be used to protect concrete from cold weather.

reached to allow formwork and cold weather protection removal. Indicate whether cylinder testing or maturity method will be used. If using the maturity method, submit a plan meeting ASTM C1074 requirements.

and location of thermometers in the concrete.

heating equipment and equipment placement.

between 50 and 85 °F (15 and 32 °C). Eliminate frozen lumps, ice, and snow before aggregates are used in production. The Contractor may warm stockpiled aggregates with dry heat or steam, but not by applying flame directly or under sheet metal. If the aggregates are in bins, steam or water coils or other heating methods may be used if aggregate quality is not affected. Live steam heating is not permitted on or through aggregates in bins. If using dry heat, increase mixing times enough to permit the dry aggregates to absorb moisture. Use equipment and methods that heat the materials evenly. Do not add chlorides, chemical admixtures, or other ingredients to the concrete to prevent freezing.

and air within the enclosure can be kept above 60 °F (15 °C) for a period of 7 calendar days or the specified curing period after placing the concrete. Ensure that the relative humidity remains above 80% within the enclosure. Before placing concrete, provide adequate preheat to raise the temperature of the formwork, reinforcing steel, adjacent concrete, and subgrade to at least 35 °F (2 °C). Furnish and place enough temperature probes within the concrete to ensure the temperature of the concrete is adequately monitored. Install a minimum of 3 temperature probes within each concrete element. Ensure that the temperature probes cannot be dislodged by the placement of concrete, vibration, or workers. Include at least 1 additional temperature probe to record ambient outside air temperature. Where heated enclosures are used, include a temperature recording device inside the heated enclosure. Temperature probe locations are subject to approval. Provide access for Department personnel to each probe for downloading recorded data.

cured cylinders meet design strength, maturity meter readings are satisfactory, or 2020 EDITION V5.1 HYDRAULIC CEMENT CONCRETE – 551 the specified curing days are reached, and all temperature recording data has been submitted.

field-cured cylinders in accordance with MT 101. Place the cylinders at locations designated by the Project Manager and expose them to the same conditions as the concrete being placed until they are removed for testing. Test field-cured cylinders within 24 hours after removal from cold weather protection according to AASHTO T 22, except that the moist cure period is omitted. Perform tests using a certified testing laboratory. Furnish the Project Manager with certified copies of the test results. Cast enough cylinders to guarantee the required strength has been met for protection removal. The Department reserves the right to witness selected tests and testing procedures. Two cylinders constitute a test with the test value being the average of the 2 compressive strengths. The average of all sets must meet the specified strength. Continue curing and protection until the tests indicate the specified compressive strength is reached.

strength is met, withdraw protection and heating in such a manner so as not to induce thermal shock stresses in the concrete. Gradually reduce the temperature of the concrete at a rate not exceeding 15 °F (9 °C) per hour. Do not exceed a temperature differential of 40 °F (4 °C) between the core of the element and the surface of the element. In addition, the temperature differential between the surface of the element and the ambient air is not to exceed 15 °F (9 °C). Ambient air temperature is defined as the temperature at mid-height of the element and 12 inches (305 mm) from the surface of the element. All concrete must achieve a minimum of 4000 psi (28 MPa) before being exposed to freeze/thaw cycles. The Contractor is solely responsible for protecting concrete from inclement weather during the entire curing period. Permission given by the Project Manager to place concrete during cold weather in no way ensures acceptance of the work by the Department. Should the concrete placed under such conditions prove unsatisfactory in any way, the Project Manager has the right to reject the work although the plan and the work were carried out with the Project Manager’s permission.

.7 Curing Concrete

Continuously water-cure any class of concrete used for bridge deck construction for 14 calendar days as specified below. Continuously water-cure class Overlay-SF for 7 calendar days as specified below. Continuously water-cure class Overlay-LM for 72 hours as specified below, followed by a dry cure. Begin the dry cure at the end of the 72-hour wet cure period by removing the burlap and the polyethylene. Allow the concrete to undergo 48 hours of dry cure. Keep the bridge closed to traffic an additional 48 hours if the air temperature falls below 50 °F (10 °C) during the cure. Allow no traffic on the overlay surface until the end of the dry cure and the transverse deck grooving has been completed. – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1 Continuously cure all other concrete surfaces for 7 calendar days by either water-curing or liquid membrane-forming curing compound as specified below. Design strength must be verified by field-cured cylinders in accordance with AASHTO T 22. Do not place curing compounds on concrete that is still bleeding. Protect freshly placed concrete from freezing, high temperatures, large temperature differentials, premature drying, excessive moisture, and moisture loss for the period of time necessary to develop the desired concrete properties. Protect exposed concrete surfaces from premature drying by covering with canvas, plastic sheets with sealed joints, burlap, or other approved materials. Keep the concrete moist. Continually moisten uncovered surfaces by fogging. Do not allow water to drip, flow, or puddle on the concrete surface during fog misting, when placing the burlap, or at any time before the concrete has achieved final set. Do not use intermediate monomolecular film curing agents (evaporation retarders) as a method to reduce moisture loss. The concrete surfaces against forms may be cured by leaving the forms in place for at least 7 calendar days. Keep the concrete surfaces moist after removing forms until surface repair is completed and one of the final cure methods described below is used. Surface repair includes removal of irregularities and repair of all depressions, voids, and air holes. After placement, cure concrete surfaces as follows:

burlap is placed. Place wet burlap in accordance with Subsection 717.01.2 immediately behind concreting operations no later than 15 minutes after finishing. Do not use products that have a laminated moisture barrier. Soak burlap for a minimum of 24 hours before use. Keep the burlap wet until concrete reaches sufficient strength to place soaker hoses or other effective means of providing moisture without marring the surface. Once a watering system is placed, place an approved reflective type sheeting, or blanket over the watering system in accordance with Subsection

717.01.1 and cover to reduce evaporation. The

entire concrete surface must remain moist throughout the full cure period. Ensure the temperature of all water used in the water cure is within 20 °F (11 °C) of the in-place concrete temperature. Secure covers and sheeting to prevent them from being lifted or displaced.

membrane-forming curing compound in accordance with Subsection 717.01.3 or

.4 over exposed surfaces

Deliver membrane-curing compound to the job in the manufacturer’s original container, clearly labeled with the manufacturer’s name and contents. The compound must be ready to use as shipped by the manufacturer. Do not dilute the compound. Do not use curing compound without providing the Project Manager a manufacturer’s product data sheet. Use white-pigmented compound for pavements. Apply curing compound homogeneously to provide a uniform, solid, white opaque coverage on all exposed concrete surfaces (having an appearance resembling a white sheet) at the time of application. 2020 EDITION V5.1 HYDRAULIC CEMENT CONCRETE – 551 Use products in accordance with Subsection 717.01.4 on curbs, sidewalks, median caps, and barrier rail. Use a product in accordance with Subsection 717.01.3 on substructure components, superstructure components other than those requiring a water cure, and all other exposed concrete surfaces. Ensure products furnished in accordance with Subsection

.3 are clear and contain a fugitive dye that makes the film visible

on the concrete for at least 4 hours after application but does not affect the concrete surfaces natural color after curing. Thoroughly mix and apply the compound following the manufacturer’s instructions or apply at a rate exceeding 1 gallon per 150 square feet (0.27 L/m2) and ensure complete coverage with no transparent areas showing obvious color differential. Apply the curing compound immediately after the finishing operation using a mechanical pressure distribution system to provide uniform coverage. During windy conditions, equip the spray nozzles with hoods. When concrete is placed in forms, immediately apply the curing compound after form removal if the concrete has not reached its design strength. A hand-operated sprayer providing uniform coverage may be used to apply liquid curing compound to areas where a mechanical sprayer is impractical. If the curing membrane is damaged from any cause during the curing period, re-coat the damaged areas immediately. Do not apply membrane-curing compound to construction joint surfaces. Protect exposed steel during application of curing compounds.

for steam-cured members using curing blankets or other approved flexible coverings. Provide a minimum of 6 inches (150 mm) of free air space between the enclosure or coverings and all concrete surfaces. Secure flexible coverings to prevent moisture loss. Provide moisture before the cure cycle to aid hydration and prevent surface cracks caused by rapid water loss from the concrete. Steam may be introduced before starting the cure cycle if the enclosure temperatures are maintained between 50 and 70 °F (10 and 21 °C). Fog-spray or cover the top surfaces of the members with wet blankets within 15 minutes after placing concrete to prevent moisture loss for a 3-hour period before the cure cycle. Begin the steam-cure cycle after the concrete has been in place for at least 3 hours. Maintain steam at 100% relative humidity, applied so it does not damage the surface of the concrete, forms, or tendons. Raise the ambient temperature within the enclosures no faster than 40 °F (22 °C) per hour to a maximum temperature between 120 and 160 °F (49 and 71 °C). Maintain the temperature until the concrete has reached strength for transfer of prestress or design strength. Once the cure cycle is complete, cool the precast items by decreasing the temperature within the enclosures no faster than 40 °F (22 °C) per hour until the temperature difference between the inside and outside air is within 25 °F (14 °C), unless otherwise approved. Keep a curing time-temperature record for each concrete placement within the casting bed. Provide 1 automatic temperature-recording thermometer for each 200 feet (61 m), or fraction thereof, of continuous bed length used. Record curing temperatures – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1 continuously for the full curing cycle. Place the temperature sensors at approved locations. Supplement automatic recording thermometers with standard bulb-type thermometers placed at approved locations. Certify the accuracy of automatic recorders once each year or when the recorder accuracy is in question. Steam curing is not permitted without automatic recorders. The sideforms may be removed at the Contractor’s discretion. Assume all responsibility removing forms before breaking the release cylinders. Concrete members damaged from early form removal will be rejected. The cure cycle may be interrupted for a maximum of 20 minutes for form removal. Do not expose the members to below-freezing temperatures within 6 calendar days of casting. In place of the 6-day requirement, the cure time may be based on the concrete strength. The concrete strength is determined by the average strengths of 3 standard 6 x 12-inch (152 x 305 mm), or 4 x 8-inch (102 x 203 mm) cylinders cast from different batches of concrete used in each casting. Expose these cylinders to the same cure and temperature conditions as the precast items. Immediately test the cylinders according to AASHTO T 22 without further curing once they are removed from the cure area. Curing may be discontinued if the average strengths of the 3 cylinders equal or exceeds specified strengths. Protect the member from freezing temperatures for the 6- day period if the average compressive strength fails to meet specified strength. Cool all members as specified in this Subsection. Cast compression cylinders for field tests of the 28-day strengths following MT 101. Cast the number of test cylinders as required in Subsection 551.03.8(C) and MT 111. The Contractor may submit in writing, alternate curing methods, for approval.

.8 Testing and Acceptance of Concrete

Construct any products that are not cast-in-place, and not produced at a PCI, ACPA or NPCA certified precast plant, in accordance with Subsection 605.03. These products will be evaluated on a lot-by-lot basis in accordance with Subsection 551.03.8(C) for the class of concrete specified.

required for concrete placements smaller than 7 cubic yards (m3). The Department will perform pre-tests for air content and slump at the start of each concrete production run and any time there is a significant change in the pumping configuration or concrete placement as determined by the Project Manager. Meet the following requirements:

specifications, placement may begin.

admixtures included in the mix design, in accordance with Subsection 551.03.3(H) .

second pretest again produces a failing result, the truck will be rejected. The testing process will be repeated on subsequent trucks until passing air and slump results are achieved. Pre-test results are not used for concrete lot acceptance.

accordance with AASHTO R 60 from the point of placement to an area designated by the Project Manager for testing of concrete properties and molding of test specimens. Do not 2020 EDITION V5.1 HYDRAULIC CEMENT CONCRETE – 551 drop or agitate samples. The sampling and transport must be witnessed by the Department. The Department will take possession of the sample and begin the following applicable tests.

strength following AASHTO R 60. Test cylinders will be cast and cured following MT 101 and tested in accordance with AASHTO T 22 at a frequency determined by MT 601. Test cylinders for SCC will be cast and cured in accordance with MT 117. Test cylinders for CLSM will be cast and cured in accordance with ASTM D4832. Compressive strength tests may be molded at any time if inconsistency between batches is identified or suspected. A compressive strength set consists of 4 test cylinders made at the same time from the same batch of concrete. Tests for plastic properties will also be run from the same sample used for compressive strength tests. The Contractor may make additional cylinders to determine strength gain and to maintain job control. Standard compressive strength tests will be made at 7 and 28 days, except as specified below for concrete used in prestressed members. The compressive strength results of the cylinders tested will determine if the concrete meets the required compressive strength in Table 551-2or specified in the contract.

concrete placement, including air content, temperature, and slump to maintain job control. Furnish samples for determining slump, air, and temperature in accordance with AASHTO R 60. Slump will be tested in accordance with AASHTO T 119. Air content will be determined in accordance with AASHTO T 152. Temperature will be tested in accordance with ASTM C1064 at a frequency determined in accordance with MT 601 . Plastic properties tests may be run at any time if inconsistency between batches is identified or suspected. Slump flow and air content for SCC will be evaluated in accordance with AASHTO T 347 and AASHTO T 152. Plastic concrete will also be subjected to a visual test for segregation. If segregation is identified by a “halo”, bleeding, aggregate agglomerations, or aggregate settlement (identified by a high sheen or bubbling) during the slump test, do not place the concrete. Take immediate steps to resolve the problem. Remove and replace any concrete placed showing signs of segregation at no expense to the department.

following AASHTO R 60. Test cylinders will be cast and cured following MT 101 and tested in accordance with AASHTO T 358. The Department may test hardened air content in accordance with ASTM C457 for acceptance.

sampled in accordance with MT 201 and tested in accordance with MT 202. Combined gradations are determined in accordance with MT 122.

following: – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1

These classes of concrete are evaluated for acceptance on a lot-by-lot basis. An individual lot is defined as a single day’s placement or every 200 yd3 (150 m3) of concrete placed (i.e., 200 yd3 = 1 lot, 400 yd3 = 2 lots, etc.) whichever is less, excluding Class Pave. If predetermined, the Project Manager may elect to define a lot as the cumulative concrete placed when multiple small placements result in a quantity of 30 cubic yards or less over 3 consecutive placement days, not spanning more than 5 business days. An individual lot of Class Pave concrete is defined as a single day’s placement or every 1,000 yd 3 (750 m3) of concrete placed, whichever is less. Each lot is accepted or rejected based on the lot acceptance air tests, strength tests, gradation tests and when applicable, permeability tests. The pay factors for each lot accepted are determined from Table 551-5, 551-6, 551-7, 551-8 and 551-9 . The overall lot pay factor (OLPF) will be calculated for bid items as shown in Table 551-4 and will be applied as a line item adjustment on the estimate. TABLE 551-4 ITEMS INCLUDED FOR PAY FACTOR ADJUSTMENT Class Items Deck Include all items except metal bridge rail and bridge deck repair Drilled Shaft Include all items Overlay-SF Pave Structure Include concrete class bid items and Revise Barrier items General Include concrete class bid items Include items in Subsection 608 Include items in Subsection 609 Include items measured by the volume Exclude all other items Note 1: The OLPF may be evaluated on other contract items that have significant equivalent concrete quantities. Pay factors will not be calculated for items measured and paid for by the Lump Sum or precast items accepted in accordance with Section 554. Except for concrete barrier rail, pay factors will not be calculated for items measured and paid for by the each. Concrete barrier rail and other items constructed in accordance with Section 605 will be tested and accepted the same as cast-in-place items.

for each lot. Each set will be made from concrete taken from a separate batch or load randomly selected from all loads or batches in the lot. For a lot less than 30 cubic yards (23 m 3), the Project Manager may elect to make 1 set of compressive strength cylinders to represent that lot. Three cylinders from each set of cylinders are tested for compressive strength at 28 days and the fourth is tested at 7 days. The test result is the average of the strengths of the 3 individual 28 day cylinder specimens unless an outlier is identified. 2020 EDITION V5.1 HYDRAULIC CEMENT CONCRETE – 551 For classes Deck and Overlay, if the average 28-day strength of all sets within a lot is ±500 psi of the mix design target and greater than 4000 psi, the lot is eligible for a 1.02 PFS. Any results below 4000 psi will be evaluated in accordance with Table 551-5. The Department will analyze the test results for outliers. The results of the 2 specimens with the closest compressive strengths will be averaged. If the strength result of the remaining cylinder differs by more than 10% from that average, it will be considered an outlier. If an outlier is identified, that specimen will be removed, and the average strength of the set will be determined using the remaining 2 specimens. The lot acceptance strength is the average of all sets for the lot. TABLE 551-5 CONCRETE STRENGTH PAY FACTORS Strength Pay Factors Classes Deck, Overlay, Structure, General, Pave, and Drilled Shaft Concrete lot acceptance strength, x psi (1 psi = 6.9 kPa) strength, x (psi) strength pay factor, PFS x ≥ 4,000 𝑃𝑃𝑃𝑃𝑆𝑆 = 1.00 4,000 > x ≥ 3,500 𝑃𝑃𝑃𝑃𝑆𝑆 = 1.00 − 0.15(4000 − 𝑥𝑥) 500 3,500 > x ≥ 2,800 𝑃𝑃𝑃𝑃𝑆𝑆 = 0.85 − 0.85(3500 − 𝑥𝑥) 700 2,800 > x PFS = 0, remove and replace The pay factors shown will be used when the department determines the concrete is acceptable at less than the specified strength. The Department may require removal and replacement or corrective action for any concrete not in accordance with the required strength.

Concrete air content will be determined in accordance with AASHTO T 152 or ASTM C457 on the same sample used to make the compression test cylinders for acceptance and on samples taken according to MT 601 . A separate air content pay factor will be computed for each test result and the lot air content pay factor will be the average of the individual test result pay factors. The pay factor for each lot based on air content is determined from Table 551-6. – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1 TABLE 551-6 AIR CONTENT PAY FACTORS Lot Acceptance, Air Content Classes General, Pave, Deck, Overlay, and Structure Concrete Used when mix design incorporates ≥ 1½-inch nominal maximum aggregate gradation Air content, x (%) Air content pay factor, PFAC Air content, x (%) Air content pay factor, PFAC x ≥ 7.5% 𝑃𝑃𝑃𝑃𝐴𝐴𝐴𝐴 = 1.00 x ≥ 6.5% 𝑃𝑃𝑃𝑃𝐴𝐴𝐴𝐴 = 1.00 7.5% > x ≥ 6.5% 𝑃𝑃𝑃𝑃𝐴𝐴𝐴𝐴 = 1.03 6.5% > x ≥ 5.5% 𝑃𝑃𝑃𝑃𝐴𝐴𝐴𝐴 = 1.03 6.5% > x ≥ 5.0% 𝑃𝑃𝑃𝑃𝐴𝐴𝐴𝐴 = 1.00 5.5% > x ≥ 4.0% 𝑃𝑃𝑃𝑃𝐴𝐴𝐴𝐴 = 1.00 5.0% > x ≥ 3.0% 𝑃𝑃𝑃𝑃𝐴𝐴𝐴𝐴 = 1.0 − 0.25(5.0 − 𝑥𝑥) 4.0% > x ≥ 2.5% 𝑃𝑃𝑃𝑃𝐴𝐴𝐴𝐴 = 1.0 − 0.33(4.0 − 𝑥𝑥) 3.0% > x Remove and Replace 2.5% > x Remove and Replace The pay factors shown will be used when the department determines the air content of the in-place concrete is acceptable at percentages less than specified. The Department may require removal and replacement or corrective action for any concrete not in accordance with the required air contents. No incentive will be paid if any individual air test within the lot is outside the range specified in Table 551-2. In addition to the air content pay factor, coating concrete with an approved penetrating epoxy sealer at no cost to the Department will be required any time concrete having an air content less than 4.0% (3.5% for concrete containing 1½- inch nominal aggregate) for Classes Deck, Overlay, and Structure concrete allowed to remain in place. Air content pay factors will not be used on Class Drilled Shaft concrete.

551-7) or 56 days (Table 551-8 ) in accordance with either AASHTO T 358 (Table 551-7). At least one set of compressive strength cylinders per lot will also be tested for permeability. The lot acceptance permeability is the average of the test results for the lot. If 6-inch by 12-inch specimens are required based on use of 1½-inch nominal aggregate, the acceptance values in Tables 551-7 and 551-8 will be reduced by 20%. The pay factor for each lot based on permeability is determined from Table 551-7 or Table 551-8. 2020 EDITION V5.1 HYDRAULIC CEMENT CONCRETE – 551 TABLE 551-7 28-DAY CONCRETE PERMEABILITY PAY FACTORS Lot Acceptance, Permeability, x (kΩ-cm) Classes Deck and Overlay1 lot permeability test result, x (kΩ-cm) permeability pay factor, PFP x ≥ 21 𝑃𝑃𝑃𝑃𝑃𝑃 = 1.05 21 > x ≥ 12 𝑃𝑃𝑃𝑃𝑃𝑃 = 1.00 12 > x ≥ 10 𝑃𝑃𝑃𝑃𝑃𝑃 = 1.00 − 0.30(12 − 𝑥𝑥) 10 > x 𝑃𝑃𝑃𝑃𝑃𝑃 = 0.70 Note 1: If Class Structure is specified for a bridge deck, the incentive may be paid, but no deduction will occur for permeability results. TABLE 551-8 56-DAY CONCRETE PERMEABILITY PAY FACTORS Lot Acceptance, Permeability, x (kΩ-cm) Classes Deck and Overlay lot permeability test result, x (kΩ-cm) permeability pay factor, PFP x ≥ 21 𝑃𝑃𝑃𝑃𝑃𝑃 = 1.00 21 > x ≥ 18 𝑃𝑃𝑃𝑃𝑃𝑃 = 1.00 − 0.30(21 − 𝑥𝑥) 18 > x 𝑃𝑃𝑃𝑃𝑃𝑃 = 0.70 The pay factors shown will be used when the department determines the permeability of the in-place concrete is acceptable with results less than specified. The Department may require removal and replacement or corrective action for any concrete not in accordance with the required permeability.

with MT 202 or MT 122 , if applicable. A minimum of one gradation test will be performed per 200 cubic yards (150 m3) excluding class Pave. The test result will be used in the OLPF calculation for each lot of concrete placed within that 200 cubic yards (150 m 3). For class Pave, a minimum of one gradation test will be performed per 1000 cubic yards (750 m3). 1) Conventional Gradations. For concrete designed with conventional gradations, the Department will calculate the pay factor for the gradation using the following formula. – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1 𝑃𝑃𝑃𝑃𝐺𝐺 = 1.00 − (𝑥𝑥) 1000 Where: x = The sum of the individual percentages out of range on each aggregate fraction. PF = Pay Factor 2) Optimized Gradations. For concrete designed with optimized gradations the Department will calculate the pay factor for the gradation using the following formula 𝑃𝑃𝑃𝑃𝐺𝐺 = 1.00 − 0.25(𝑥𝑥) + 2(𝑦𝑦) 250 Where: x = The sum of percentages out of tolerance on each individual aggregate fraction (each rounded to the whole number). y = Percentage out of tolerance on the No. 200 (0.075 mm) sieve fraction (rounded to the tenth of a percent). PF = Pay Factor If all gradation tests in the lot produce passing results, the following pay factor will be used: 𝑃𝑃𝑃𝑃 𝐺𝐺 = 1.05 T he following formulas are used to calculate the OLPF and unit price adjustment ADJ. All pay factors (PFS, PFP, PFAC, and PFG) must be 1.00 or greater for the production lot to be eligible for positive ADJ (incentive). No OLPF can exceed 1.15. 𝑂𝑂𝑂𝑂 𝑃𝑃𝑃𝑃 = 𝑃𝑃𝑃𝑃𝑆𝑆 × 𝑃𝑃𝑃𝑃𝐴𝐴𝐴𝐴 × 𝑃𝑃𝑃𝑃𝑃𝑃 × 𝑃𝑃𝑃𝑃𝐺𝐺 𝐴𝐴𝐴𝐴𝐴𝐴 = (𝑂𝑂𝑂𝑂 𝑃𝑃𝑃𝑃 − 1) × 𝑃𝑃 𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 W here: ADJ = Price adjustment per pay unit to be applied to the production lot quantity Price = Contract unit price for the pay item If a pay factor is not applicable to a specific class of concrete, the pay factor (PF) will be 1.00. Use Table 551-9 to determine pay factors applicable to specific classes of concrete. TABLE 551-9 PAY FACTORS FOR CONCRETE PF Type Deck Overlay Structure General Drilled Shaft Pave PFS X X X X X X PFAC X X X X X PFP X X PFG X X X X X X 2020 EDITION V5.1 HYDRAULIC CEMENT CONCRETE – 551

basis based on the average of the 28-day compressive strength cylinders and variation in test results as measured by the standard deviation. Each lot will be judged against the formula: F'c + 0.35S Where: S is the standard deviation of the strengths for the three 28-day cylinders. F'c is the concrete strength required for final acceptance as specified in the contract. A lot is defined as all the concrete that is placed in a single pre-cast prestressed member. Lots with any actual average cylinder strengths less than that calculated from the above formula will be rejected. Three 28-day compressive test cylinders will be made for each lot, and each 28- day test cylinder sample will be randomly selected from all batches or loads. The strengths of other cylinders made from a sample and tested at an earlier age will not be considered for acceptance purposes. The cylinders for acceptance will be cast in accordance with MT 101, sampled in accordance with MT 111 and tested in accordance with AASHTO T 22. The cylinders will be cured within the curing enclosure under the exact conditions and methods used to cure the prestressed member until transfer of pre-stress. After transfer of pre-stress, the cylinders will be transported and continue curing in accordance with MT 101.

placements that support traffic loads. CLSM will be accepted by certification for placements that do not support traffic loads. CLSM will be tested in accordance with MT 601 . Do not apply additional loads until CLSM has reached its design strength.

or less of concrete without a formal mix design. Submit a batch proportion sheet for approval before use. Classes Deck, Overlay, and Structure concrete are excluded from this exception. In accordance with Section 3.1.1 of MT 601 the Project Manager may designate 9 cubic yards (6.9 m3) or less concrete as a “small quantity” for acceptance sampling and testing.

551.04METHOD OF MEASUREMENT

Concrete is measured by the cubic yard (m3) in accordance with Subsection 552.04, unless otherwise specified. Class Pave concrete is measured for payment in accordance with Subsection 501.04. Class Pre concrete is measured for payment in accordance with Subsection 553.04. Concrete used in pre-cast concrete products is measured for payment in accordance with Subsection 554.04.

551.05BASIS OF PAYMENT

Payment for the completed and accepted quantities is made under the following: – HYDRAULIC CEMENT CONCRETE 2020 EDITION V5.1 Pay Item Pay Unit Concrete Cubic Yard (m3) Class Pave concrete is paid for in accordance with Subsection 501.05. Class Pre concrete used in prestressed concrete members is paid for in accordance with Subsection 553.05. Concrete used in pre-cast concrete products is paid for in accordance with Subsection

554.05