499.01 300 ITEM 499 CONCRETE —GENERAL
499.01 Description
499.02 Materials
499.03 Concrete Mix Design
499.04 Adjustments and Controls
499.05 Equipment
499.06 Handling, Measuring, and Batching Materials
499.07 Batch Plant Tickets
499.08 Mixing Concrete
499.01 Description. This specification consists of proportioning requirements
for portland cement concrete mix designs, mixing, adjustments and controls , and batch plant requirements for portland cement concrete.
499.02 Materials. Furnish materials conforming to:
Portland cement ............................. 701.01, 701.02, 701.04 ........................ 701.05 and 701.09 or blended cement[1] Micro -silica ................................ ............................ 701.10 Slag cement ................................ ............................ 701.11 Fly ash ................................ ................................ .... 701.13 Fine aggregate [2][3] ................................ ................. 703.02 Coarse aggregate[3] ................................ ... 703.02, 703.13[4] Recycled Concrete Aggregate (RCA) ..... Supplement 1117 Air-entraining admixture ................................ ........ 705.10 Chemical admixture for concrete[5] ........................ 705.12 Carbonate micro-fines ................................ ............ 705.27 [1] If blended cement is used, provide mill certification of all the cement and pozzolanic components and final product for approval by the Office of Materials Management [2] 703.02 natural sand or sand manufactured from stone as specified in Item 703.02.A.3 is required in 255, 256, 451, 452, 526, and 511 deck slabs. [3] Aggregates may be standard gradation sizes from 703.02 and Table 703.01 -1 or they may be a modified gradation defined with the mix design submittal and certified by the Office of Materials Management under Supplement 1069. [4] Applies only to 305, 451 and 452 concrete. [5] Admixtures shall contain no more than 50 parts per million chloride ions by weight of cement except for Type C accelerating admixtures or calcium chloride for Q C-FS only Use water for concrete mixing free from sewage, oil, acid, strong alkalis, vegetable matter, clay, and loam. Potable water is satisfactory for use in concrete. Non-potable water will meet the requirements of ASTM C1602. Water from a reclaiming system will contain no more than 0.06% chlorides. Test the non -potable water monthly and maintain data verifying that the water meets the requirements. Provide the data at the Engineer’s request.
499.03 Concrete Mix Designs . Develop concrete mix designs w ith 1 -inch
maximum nominal size coarse aggregate according to ACI 301, Section 4 meeting the requirements of Table 499.03 -1. Limit the pozzolan and carbonate micro -fines content of any mix design according to Table 499.03 -2 and Table 499.03 -3. The design air for concrete with 1 -inch nominal maximum size aggregate is 7%. Develop concrete mix designs per this specification and Supplement 1126. 499.03 301 Only use mix designs accepted by the Department and issued a JMF number. TABLE 499.03 -1 CONCR ETE MIX D ESIGN REQUIREMENTS Quantities per Cubic Yard (Cubic Meter) Provide Concrete with 7±2% Air Content Class Design Strength psi (MPa) Permeability [1] Maximum (Coulombs) Cementitious Content [2] Minimum. lbs (kg) Aggregate Requirements QC 1 4,000 (28.0) at 28 days 2,000 520 (236) Well -Graded QC 1P[9] 4,000 (28.0) at 28 days 2,000 520 (236) Well -Graded QC 2 4,500 (31.0) at 28 days 1,500 520 (236) Well -Graded QC 3 Special As per plan 1,500 or as per plan 520 (236) or as per plan Well -Graded or as per plan QC 4 Mass Concrete 4,000 (28.0) or as per plan [3] 2,000 or as per plan 470 (213) [4] [5] or as per plan Well -Graded or as per plan QC 5 [8] 4500 (31.0) at 28 days N/A 520 (236) 1 inch or 3/8-inch nominal maximum size QC SCC 4500 (31.0) at 28 days 1,500 or as per plan 520 (236) Well -Graded, 1 inch or 3/8-inch nominal size or as per plan QC MS See Supplement 1126 N/A 800 (363) 1-inch nominal maximum size QC FS See Supplement 1126 N/A 900 (408) 1-inch nominal maximum size QC Misc. [6] 4,000 (28.0) at 28 days N/A 550[7] (249) 1-inch nominal maximum size [1] AASHTO T277 Modified. [2] Cementitious Content includes cement and pozzolan denoted as Cm. [3] Strength for Mass Concrete (QC 4) may be tested at either 28 or 56 days. [4] Do not use Type III cement or accelerating admixtures in mass concrete. [5] The maximum fly ash or slag cement content may be increased up to 50%. [6] For QC Misc. mixes only –Water/Cementitious ratio limited to 0.50 maximum. [7] Cement or a combination of cement and up to15% fly ash or up to 30% slag cement . [8] For QC 5 mixes with 3/8 -inch nominal size, provide an air content of 8±2%. [9] Portland cement concrete pavement mix design. Determine the permeability by testing according to AASHTO T277 except moist cure the permeability samples for 7 days at 73 °F (23 °C) followed by 21 days of moist curing at 100 °F (38 °C). Perform permeability testing at 28 days. Limit pozzolan materials as a percent of total cementitious content according to Table 499.03 -2: 499.03 302 TABLE 499.03 -2 POZZO LAN MAT ERIAL S Materials Maximum Content (%) Fly Ash 25 Slag Cement 30 Micro -Silica 10 When using multiple pozzolan materials, do not exceed the individual maximum contents above for each material. A combination of pozzolan materials may not exceed 50% of the total cementitious content by weight. Limit carbonate micro -fines as a percent of total cementitious content according to Table 499.03 -3: TABLE 499.03 -3 CARBONATE MICRO -FINE S MATERIALS Material Maximum Content (%) Carbonate Micro -Fines 20 Do not use carbonate micro -fines in Class QC 2 or QC 3 concrete.
A.Slump and SCC Slump Flow . Maintain slump within the nominal slump range in Table 499.03 -4. If below the maximum water -cementitious ratio of the Job Mix Formula (JMF), adjust the quantity of water to meet slump requirements. Do not use concrete with a slump greater than the maximum shown in Table 499.03 -4. Conduct tests on the plastic concrete for pavement at the point of placement o r at an Engineer -designated location. TABLE 499.03 -4 CONCRETE SLUMP Type of Work Nominal Slump inch (mm)[1] Maximum Slump inch (mm)[2] Concrete pavement (305, 451, 452, 615) 1 to 3 (25 to 75) 4 (100) Structural Concrete (511, 610, 622) 1 to 4 (25 to 100) 5 (125) Superstructure concrete (511, 526) 2 to 4 (50 to 100) 4 (100) Non-reinforced concrete (601, 602,611, 608, 609, 622) 1 to 4 (25 to 100) 5 (125) [1] This nominal slump may be increased to 6 inches (150 mm), provided the increase in slump is achieved by adding a chemical admixture conforming to the requirements of 705.12, Type F or G. [2] This maximum slump may be increased to 7 inches (180 mm), provided the increase in slump is achieved by adding a chemical admixture conforming to the requirements of 705.12, Type F or G. Maintain slump flow within the nominal slump flow range in Table 499.03 -
5.Do not use concrete with a slump flow greater than the specified maximum for the SCC Class shown in Table 499.03 -5. Test for slump flow and Visual Stability Index (VSI) according to ASTM C 1611. Provide a VSI of zero (0) or one (1) according to the Appendix in ASTM C1611. 499.04 303 TABLE 499.03 -5 CONCR ETE SLUMP FLOW SCC Class Minimum Slump Flow inch (mm) Nominal Slump Flow inch (mm) Maximum Slump Flow inch (mm) Class I 18 (460) 20 (508) 22 (560) Class II 22 (560) 24 (600) 26 (660) Class III 26 (660) 28 (710) 30 (760)
B.Air Content. Ensure that the air content in all concrete at the point of placement is within the percentage range specified in Table 499.03 -1.
499.04 Adjustments and Controls . Provide the following adjustments and
controls during batching and placement of the concrete:
A.Batch the concrete to the proportions of the accepted JMF. Provide a workable and finishable mix. Adjustments to the JMF’s aggregate proportions up to 100 lbs (44 kg) for workability may be made. Adjustments greater than 100 lbs (44 kg) may be made if approved by the Engineer. Maintain an absolute volume of 27.0 cubic feet/cubic yar d for the adjusted concrete mix. For Well Graded JMF adjustments, maintain the combined aggregate gradation within the optimal zone II requirements for well -graded mixes as defined in Supplement 1126. If outside the optimal zone II of the Coarseness Factor Chart adjust the JMF’s proportions to maintain the combined gradation within Zone II and report the JMF changes to the Engineer.
B.Handle, haul and store aggregates to minimize segregation, avoid contamination, and assure a uniform grading within the s pecified gradation. Do not combine aggregates from different sources or of different gradings in the same stockpile. Do not use segregated or contaminated aggregates.
C.Remove all wash water by reversing each truck drum at the plant immediately prior to reloading.
D.Adjust the SSD aggregate design weights in the JMF to compensate for the moisture contained in the aggregates and moisture the aggregates will absorb during batching. Adjust the mix water to compensate for the aggregate moistures.
E.Use on ly compatible admixtures in the concrete. Dispense all admixtures according to the manufacturer’s recommendations. Furnish a volumetric dispenser for the Type F or G admixture or ensure that there is a gage on each truck -mounted Type F or G admixture dispe nsing tank. If any admixture is added at the job site, mix the load for a minimum of 5 minutes.
F.Do not exceed the maximum water/cementitious ratio or maximum water/powder ratio of the accepted JMF. Use a water -reducing admixture conforming to 705.12; proportionately increase the cementitious content; or develop and submit for acceptance a new JMF. Adjust the absolute volume of the aggregates if the cement content is increased.
G.If during placement of concrete, cement or micro -silica balling is observed, take corrective action with further mixing. If after corrective action, balling continues, reject the load. Revise the mixing process and/or loading sequence to prevent further balling. 499.05 304 H. If slump loss occurs before placement of the conc rete, the concrete may be “replasticized” with an admixture to restore plasticity. The Engineer will recheck the slump range and air content to ensure conformance to the specifications. If after “replasticizing” the components of the load are segregated, t he Department will reject the load.
I.Completely discharge the concrete from each delivery truck within the time requirements of 499.08.
J.Provide sufficient quality control at the plant to assure conformance with this specification and project requirements.
K.Use an approved set -retarding admixture conforming to 705.12, Type B or D when the concrete temperature exceeds a nominal temperature of 75 F (24 C).
499.05 Equipment. Use a Department approved batch plant and trucks. Provide
batching a nd mixing equipment meeting the following requirements:
A.Batching Plants. Operate each plant so that aggregate materials are not segregated and there is no intermingling of the materials before batching. Use weighing mechanisms that allow a visible mean s of checking weights and produce a printed record. Use dispensing mechanisms for water and admixtures that allow a visible means of checking quantities and produce a printed record. Use cement and aggregate weighing mechanisms that are accurate to within 0.5 percent of the correct weight. Ensure that devices for weighing or metering water are accurate to 1.0 percent throughout the range used. Maintain a certification from a Sealer of Weights and Measures or a scale servicing company attesting to the accu racy of the weighing and metering devices. A Certificate of Performance issued by the National Ready Mixed Concrete Association may be used instead of the Sealer of Weights and Measures or a scale servicing company. Do not use plants with a certification o r certificate older than 12 months Maintain the services of a scale servicing company or ten standard test weights to reach a capacity of 500 pounds (227 kg) for testing the weighing devices at the batch plant. Ensure all device -testing weights are sealed by the Ohio Department of Agriculture every 3 years. The Engineer may test weighing and dispensing devices as often as necessary to ensure continued accuracy.
B.Mixers. Provide mixers and agitators conforming to AASHTO M 157, Sections 10, 11.2, 11.5, and 11.6, except that the Department will allow mechanical counters. For bodies of non -agitating concrete hauling equipment, provide smooth, mortar -tight, metal containers capable of discharging the concrete at a satisfactory controlled rate without segregati on. Provide covers when required by the Engineer. The Engineer will allow trucks having dump bodies with rounded corners and no internal ribs or projections for non -agitating hauling. 499.06 305 C. Concrete Pumping and Conveying Equipment. Provide concrete pumping and conveying equipment in accordance with ACI 304.2R and ACI 304.4R. Conduct a pre -placement meeting to discuss concrete pumping and conveying procedures to maintain air content within specified limits per Table 499.03 -1.
499.06 Handling, Measuring, and Ba tching Materials . Do not stockpile
aggregates from different sources or different gradations together. Do not use aggregates that have become segregated or mixed with foreign material. The Engineer may direct reworking or cleaning, or may reject aggregates that have become segregated or mixed with earth or foreign material. Prior to and during batching, maintain all coarse aggregates at a uniform moisture content. For all slag aggregates or other aggregates with a reported absorption above 3.0 percent, ma intain the moisture contents at or above the ODOT -reported SSD for that aggregate as follows:
A.Use appropriate stockpile watering systems capable of raising and maintaining aggregate moisture at or above SSD. Test the moisture content of the watered aggregate stockpiles at least five (5) locations to assure the stockpile is at or above SSD.
B.Have processes to maintain the aggregate stockpile at SSD until stockpile draining for SSD consistency has begun. Twenty -four (24) hours before batching concrete with the aggregate, shut down the stockpile watering process to allow drainage and to establish a uniform moisture content.
C.Test aggregate moisture content at least once per half day, but not less than twice per day, during concrete production. If the moisture content varies between tests by more than 1 percent increase the moisture testing frequency to assure correct batching information.
D.Provide the moisture content test results as part of all quality control plant ticket information. Separately weigh the amounts of fine aggregate and coarse aggregate. Use a separate weighing device for cementitious materials. Batch each material to ensure weights are within the tolerance specified in Table 499.06 -1, based on the amount specified in the approved JMF. 499.07 306 TABLE 499.06 -1 CONCRETE BATCHING TOLERANCES Material Batching Tolerance (%) Cement ±1.0 Pozzolan[1] ±1.0 Carbonate Micro -fines[2] ±2.0 Aggregates[2] ±2.0 Water[3] ±1.0 Chemical Admixtures ±3.0 [1] Tolerance is on cumulative target weight when weighing together with cement [2] Tolerance is on cumulative target weight when weighing together with more than one aggregate [3] Measured by weight or volume
499.07 Batch Plant Tickets. Furnish a concrete ba tch plant ticket to the Engineer
for each load of concrete incorporated into the project. Provide computer generated batch tickets. At a minimum, include the information listed in Table 499.07 -1 on each ticket: 499.07 307 TABLE 499.07 -1 EVERY BATCH TICKET Name of ready -mix batch plant Batch plant No. Batch plant location Serial number of ticket Date Truck number Class of concrete JMF Number Batch time Batch size yd3 (m3) Actual weights and batch tolerance of cementitious material: Cement lb (kg) Fly ash lb (kg) Slag cement lb (kg) Micro -silica lb (kg) Other lb (kg) Actual weights and batch tolerance of aggregates: Coarse lb (kg) Intermediate lb (kg) Fine lb (kg) Carbonate Micro -Fines lb (kg) Other lb (kg) Actual weight of water and batch tolerance lb (kg) Actual volume of admixtures: Air-entrainer fl oz (mL) Superplasticizer fl oz (mL) Water -reducer fl oz (mL) Retarder fl oz (mL) Other fl oz (mL) Aggregate moisture contents: Coarse aggregate % Intermediate aggregate % Fine aggregate % Water -cementitious ratio, leaving the plant Provide the information in Table 499.07 -2 with batch tickets for each day’s first load of concrete and for each JMF. Include Table 499.07 -2 information on the batch ticket or furnish the information on a separate computer -generated or handwritten form attached to the batch ticket. Provide moisture adjustment calculations for all coarse and fine aggregate according to 499.06.C. 499.08 308 If during the co ncrete manufacturing process any of the information listed in Table 499.07 -2 changes, resubmit Table 499.07 -2 information with the first batch ticket supplied with the changed concrete. TABLE 499.07 -2 FIRST TICKET EACH DA Y, EACH JMF Cementitious Materials : Source: Grade or Type: Cement Fly ash Slag cement Micro -silica Other Admixtures Brand: Type: Air-entrainer Retarder Superplasticizer Water -reducer Other The provided concrete batch ticket information is according to ASTM C 94/C 94M, Section 14. The Engineer may require supporting data to validate the basis for furnished aggregate moisture contents.
499.08 Mixing Concrete. Use a central mix plant or in truck mixers to mix the
concrete. When using a central mix plant, mix the concrete not less than 60 seconds Begin the mixing time when all materials are in the drum and end the mixing time when discharge begins. Include transfer time in multiple drum mixer s in the mixing time. Remove the contents of an individual mixer drum before a succeeding batch is emptied into the drum. When concrete is mixed using a truck mixer for complete mixing, mix each batch of concrete at the rotation rate designated on the mixer as mixing speed for not less than 70 revolutions of the drum. Transport mixed concrete from the central mixers in truck mixers, truck agitators, or trucks having non -agitating bodies. Within 90 minutes after cement and water are combined, deliver and completely discharge concrete. When concrete is delivered in transit mixers and before discharging any of a batch, the Engineer may allow adding water within the specified water -cement ratio limits. Perform sufficient mixing, a minimum of 30 revolutions a t mixing speed, to adjust the slump and to regenerate the specified air content throughout the batch. When approved by the Engineer, the Contractor may use approved admixtures (705.12, Type F or G) for retempering the load to adjust the slump after the sta rt of 499.08 309 discharge. Mix for a minimum of 30 revolutions at mixing speed after addition of the admixture. Use admixtures containing no more than 50 parts per million chloride by weight of cement only when specified in the Contract Documents, the accepted JMF, or with the Engineer’s written permission. Ensure that the temperature of all concrete does not exceed 95 F (35 C) until incorporated into the work.
Source: Ohio Construction and Material Specifications, 2019 Edition. Pages 0–0 of 928.