Admixtures-Section 924

Transcription

1 Admixtures-Section Qualified Products List - Types include: - Air Entraining - Water-Reducing (Type A) - Accelerating (Type C) - Water-Reducing & Retarding (Type D) - Water-Reducer & Accelerating (Type E) - High Range Water Reducer (Type F) - High Range Water-Reducing & Retarding (Type G) - High Range Water-Reducing (Type I & Type II) for flowing and self-consolidating concretes - Corrosion Inhibitors - Air Entraining can reduce the strength of concrete General. This Section covers materials for use as admixtures for concrete. The use of admixtures is restricted to those admixtures as may be allowed or required elsewhere in the specifications for specific concrete applications. Admixtures shall comply with applicable AASHTO and ASTM specifications as modified in through Admixtures that have been previously qualified for Department use are listed on a Qualified Products List Acceptance of Admixtures Qualified Products List (QPL): The Department maintains a list of qualified admixtures for air-entraining, water-reducing (Type A), accelerating (Type C), water-reducing and retarding (Type D), water-reducer and accelerating (Type E), high range water reducing (Type F) and high range water reducing and retarding (Type G), high range water-reducing (Type I - Plasticizing and Type II - Plasticizing and retarding) in producing flowing concrete, and corrosion inhibitor, which have been determined as meeting requirements for use on Department projects. Admixtures included on this list, will be permitted without further testing.. Version 1.0-7/20/06 1

2 Environmental Classifications Slightly Aggressive Environment Moderately Aggressive Environment Extremely Aggressive Environment 2 The environmental Classification of a structure dictates the Type of cement that can be used in the structure. The Designer determines the Environmental Classification for the structure. Version 1.0-7/20/06 2

3 Environmental Classifications 3 Types of Cement Use Type I Type II Type III Type IP Type IS For use when the special properties specified for any other type are not required. For general use, more especially when moderate sulfate resistance or moderate heat of hydration is desired For use when high early strength is desired Portland-pozzolan cement for use in general concrete construction Portland blast-furnace slag cement for use in general construction Type IP (MS) Portland-pozzolan cement for use in general concrete construction with moderate sulfate resistance (MS) Version 1.0-7/20/06 3

4 Environmental Classifications Types of Cement 4 Version 1.0-7/20/06 4

5 Materials-Section Use of Fly Ash, Slag, Silica Fume, Metakaolin and Other Pozzolanic Materials Fly ash, slag, silica fume or metakaolin may be used as a cement replacement in all classes of concrete containing Type I, II and III cements. HOWEVER- Replace pound per pound (kg per kg) 1 lb. Cement 1 lb. Fly Ash Master Proportion Table (346-4 Table 3) Pozzolans and Slag: Use as desired, on an equal weight replacement basis, fly ash, silica fume, metakaolin, other pozzolans, and slag materials as a cement replacement in all classes of concrete, with the following limitations:. Version 1.0-7/20/06 5

6 Cement Replacement Calculation Assume you have a total cementitious content of 525 lbs. You are to do a 8% replacement for silica fume and 20% replacement for Fly Ash. How many pounds of cement is required? Pozzolans and Slag When fly ash, slag or silica fume is used as a cement replacement, use it on a pound (kilogram) per pound (kilogram) basis. Calculate cement replacement as shown in the example. Example - Assume a total cementitious content of 750 lb.(341 kg.) Calculate the required silica fume for a 7.6% replacement as 750 (341) by.076 = 57 lb. (26 kg.) Calculate the required fly ash for a 20% replacement as 750 (341) by 0.20 = 150 lb. (68 kg.) Cement required is 543 lbs. (247 kg.) Work Area for Math Exercise Version 1.0-7/20/06 6

7 Pozzolans & Slag- Section Use as desired, on an equal weight replacement basis, fly ash, silica fume, metakaolin, other pozzolans, and slag materials as a cement replacement in all classes of concrete, with the following limitations: (1) Mass Concrete: a. Fly Ash-ensure that the quantity of cement replaced with fly ash is 18% to 50% by weight, except where the expected core temperature is to rise above 165 F. When the core temperature is expected to rise above 165 F, the percentage of fly ash is required to be 35% to 50% by weight Pozzolans and Slag: Use as desired, on an equal weight replacement basis, fly ash, silica fume, metakaolin, other pozzolans, and slag materials as a cement replacement in all classes of concrete, with the following limitations: (1) Mass Concrete: a. Fly Ash-ensure that the quantity of cement replaced with fly ash is 18% to 50% by weight, except where the expected core temperature is to rise above 165 F. When the core temperature is expected to rise above 165 F, the percentage of fly ash is required to be 35% to 50% by weight. Version 1.0-7/20/06 7

8 Pozzolans & Slag- Section b. Slag-ensure that the quantity of cement replaced with slag is 50% to 70% by weight. Ensure that slag is 50% to 55% of total cementitious content by weight of total cementitious materials when used in combination with silica fume and/or metakaolin. c. For Slightly and Moderately Aggressive environments ensure that there is at least 20% fly ash by weight and 40% Portland cement by weight for mixes containing Portland cement, fly ash and slag Pozzolans and Slag:.b. Slag-ensure that the quantity of cement replaced with slag is 50% to 70% by weight. Ensure that slag is 50% to 55% of total cementitious content by weight of total cementitious materials when used in combination with silica fume and/or metakaolin. c. For Slightly and Moderately Aggressive environments ensure that there is at least 20% fly ash by weight and 40% Portland cement by weight for mixes containing Portland cement, fly ash and slag. (2) Drilled Shaft: a. Fly Ash-ensure that the quantity of cement replaced with fly ash is 33% to 37% by weight. b. Slag-ensure that the quantity of cement replaced with slag is 58% to 62% by weight. (3) For all other concrete uses not covered in (1) and (2) above, a. Fly Ash-ensure that the quantity of cement replaced with fly ash is 18% to 22% by weight. b. Slag-ensure that the quantity of cement replaced with slag is 25% to 70% for Slightly and Moderately Aggressive environments, and 50% to 70% by weight when used in Extremely Aggressive environments. Ensure that slag is 50% to 55% of total cementitious content by weight of total cementitious materials when use in combination with silica fume and/or metakaolin. Version 1.0-7/20/06 8

9 Pozzolans & Slag- Section Can be used as a cement replacement (equal; one for one) on all classes of concrete with following limitations: Drilled Shafts Fly Ash-ensure that the quantity of cement replaced with fly ash is 33% to 37% by weight. Slag-ensure that the quantity of cement replaced with slag is 58% to 62% by weight Pozzolans and Slag: (2) Drilled Shaft: a. Fly Ash-ensure that the quantity of cement replaced with fly ash is 33% to 37% by weight. b. Slag-ensure that the quantity of cement replaced with slag is 58% to 62% by weight. (3) For all other concrete uses not covered in (1) and (2) above, a. Fly Ash-ensure that the quantity of cement replaced with fly ash is 18% to 22% by weight. b. Slag-ensure that the quantity of cement replaced with slag is 25% to 70% for Slightly and Moderately Aggressive environments, and 50% to 70% by weight when used in Extremely Aggressive environments. Ensure that slag is 50% to 55% of total cementitious content by weight of total cementitious materials when use in combination with silica fume and/or metakaolin. Version 1.0-7/20/06 9

10 Pozzolans & Slag- Section All Other Classes of Concrete Fly Ash- 18% to 22% by weight. Slag- 25% to 70% for Slightly and Moderately Aggressive environments; 50% to 70% in Extremely Aggressive environments; 50% to 55% with silica fume and/or metakaolin. Slightly & Moderately Aggressive environments- at least 20% fly ash by weight, 40% Portland cement by weight for mixes containing Portland cement, fly ash and slag Continued (3) For all other concrete uses not covered in (1) and (2) above, a. Fly Ash-ensure that the quantity of cement replaced with fly ash is 18% to 22% by weight. b. Slag-ensure that the quantity of cement replaced with slag is 25% to 70% for Slightly and Moderately Aggressive environments, and 50% to 70% by weight when used in Extremely Aggressive environments. Ensure that slag is 50% to 55% of total cementitious content by weight of total cementitious materials when used in combination with silica fume and/or metakaolin. c. As an option for Slightly and Moderately Aggressive environments ensure that there is at least 20% fly ash by weight and 40% Portland cement by weight for mixes containing Portland cement, fly ash and slag. (4) Type IP (MS): Ensure that the quantity of pozzolan in Type IP (MS) is in the range of 15% to 40% by weight. Version 1.0-7/20/06 10

11 Pozzolans & Slag- Section All Other Classes of Concrete (Continued) (5) Silica Fume and Metakaolin: Cure in accordance with the manufacturer s recommendation and approved by the Engineer. Silica Fume- 7% to 9% by weight. Metakaolin- 8% to 12% by weight Continued (5) Silica Fume and Metakaolin: a. Cure in accordance with the manufacturer s recommendation and approved by the Engineer. b. Silica Fume-ensure that the quantity of cementitious material replaced with silica fume is 7% to 9% by weight. c. Metakaolin-ensure that the quantity of cementitious material replaced with metakaolin is 8% to 12% by weight. Version 1.0-7/20/06 11

12 Materials-Section Produce all concrete with Size No. 57, 67 or 78 coarse aggregate. Exceptions: -Engineers approval for No. 8 or No. 89 size blended with No. 57 or No. 67, or may be used alone Coarse Aggregate Gradation: Produce all concrete using Size No. 57 or Size No. 67 coarse aggregate. With the Engineer s approval, Size No. 8 or Size No. 89 may be used either alone or blended with Size No. 57 or Size No. 67. The Engineer will consider requests for approval of other gradations individually. Submit sufficient statistical data to establish production quality and uniformity of the subject aggregates, and establish the quality and uniformity of the resultant concrete. Furnish aggregate gradations sized larger than nominal maximum size of 1.5 inch [37.5 mm] as two components. Ensure the maximum coarse aggregate size does not violate the reinforcement spacing provisions given for reinforced concrete in the AASHTO Standard Specifications for Highway Bridges. See following full-size table Photograph of a structure prepared for concrete placement. Version 1.0-7/20/06 12

13 Materials-Section Admixture Requirements - Use Type A or Type D - Engineer s approval required for others - Admixtures containing calcium chloride are not permitted in reinforced concrete Air Entraining Admixtures - Use in all concrete except counterweight concrete Water Reducer/Water Reducer Retardant Admixtures: Use waterreducing admixture, Type A, or water-reducing and retarding admixture, Type D. Use in accordance with the manufacturer s recommended dosage rate Air Entrainment Admixtures: Use an air entraining admixture in all concrete mixes except counterweight concrete. Close-up photograph of standard concrete and air-entrained concrete- Version 1.0-7/20/06 13

14 Materials-Section High Range Water Reducing and Viscosity Modifying Admixtures (Type F & G) - Use in mixes incorporating silica fume or metakaolin - Proposed use requires batching and testing or preapproved mix - Sample batches can be incorporated into unreinforced items - Can be proposed for C.I.P. except for Drilled Shafts - Target Slump no greater than 9 inches High Range Water Reducing and Viscosity Modifying Admixtures: General: The Contractor may propose the use of a Type F or G admixture, meeting the requirements of Section 924, in all classes of concrete, except for concrete used in drilled shafts. The use of High Range Water Reducing (HRWR) admixtures in concrete mixes incorporating silica fume or metakaolin is mandatory Flowing Concrete Admixtures for Precast/Prestressed Concrete: The Contractor may propose the use of a Type I or Type II admixture, meeting the requirements of Section 924. Produce flowing concrete mix with target slump of 9 inches [230 mm]. The use of flowing concrete admixtures is limited to the construction of precast/prestressed concrete products. Add the flowing concrete admixtures at the ready mixed concrete production batch plant. Version 1.0-7/20/06 14

15 Materials-Section High Range Water Reducing and Viscosity Modifying Admixtures (Type F & G)- Continued Subsequent to laboratory trial batch- field demonstration with min. 3 batches, 3 yd 3 min. each Perform inspection and plastic properties tests on each batch Demo batches slump 7 ½ to 10 ½ Establish Cutoff time Flowing Concrete Admixtures for Precast/Prestressed (Continued).Subsequent to the laboratory trial batch, perform a field demonstration of the proposed mix design by production and placement of at least three batches, 3 yd3 [2.3 m3] minimum size each,.take representative samples from each batch and perform slump, air content, density (unit weight), and temperature tests on these samples. Cast specimens from each sample for compressive strength tests..determine the workability of the demonstration concrete batches by performing the slump tests on the samples taken at 15 minute intervals. until the slump measures 6 inches [150 mm] or less.determine the time for each batch when the slump is at 7.5 inches [190 mm]. The shortest time period determined from three consecutive batches, at 7.5 inches [190 mm] slump, is considered the cutoff time of the proposed concrete mix. Produce the flowing concrete batches at slumps between 7.5 inches to 10.5 inches [190 mm to 265 mm]. Perform inspection of the demonstration concrete during batching, delivery, placement and post placement. During placement, ensure that the concrete batches meet all plastic property requirements. the Contractor may incorporate this concrete into non-reinforced concrete. Version 1.0-7/20/06 15

16 Materials-Section Corrosion Inhibitor Admixture - Mix must also contain Type II cement and Class F fly ash (ground blast furnace slag may be substituted for fly ash) - Mix must also contain water reducing retarder (Type D), or High Range Water Reducer admixture, Type G, to normalize the setting time of concrete Corrosion Inhibitor Admixture: Use only with concrete containing Type II cement, Class F fly ash or slag, and a water reducing retardant admixture, Type D, or High Range Water Reducer admixture, Type G, to normalize the setting time of concrete. Ensure that all admixtures are compatible with the corrosion inhibitor admixture. Photographs showing corrosion on concrete pile and structure. Version 1.0-7/20/06 16

17 Classification, Strength.-Section Classification, Strength, Slump and Air Content General: (a) For precast drainage systems that are manufactured at the precast plant the Contractor is permitted to use concrete meeting the requirements of ASTM C 478 [ASTM C 478M] 4,000 psi [30 MPa] in lieu of Class I or Class II concrete. (b) The Engineer may allow higher target slump, not to exceed 7 inches [180 mm], when a Type F or Type G admixtures is used. (c) The Engineer may approve a reduction in the target slump for slip-form operations. (d) When the use of silica fume or metakaolin is required as a pozzolan in Class V, Class V (Special) or Class VI concrete, ensure that the concrete does not exceed a permeability of 1,000 coulombs at 28 days,. (e) The Engineer may allow a target slump of 9.0 inches [230 mm] when Type I or II admixture is used to produce flowing concrete in the construction of precast concrete products. Version 1.0-7/20/06 17

18 Drilled Shaft- Section For dry shafts, do not test for slump loss except when temporary removable casing is used Slump between 7" to 9 ( mm) when placed Slump of 4 (100 mm) or more throughout the elapsed time Perform slump loss tests prior to shaft concrete operations Must notify Engineer 48 hrs. prior to performing Slump Loss Test Are Ambient Temperature Specific Drilled Shaft Concrete: When drilled shaft concrete is placed in any wet shaft, provide concrete in accordance with the following specified slump loss requirements. When concrete is placed in a dry excavation, do not test for slump loss, except where a temporary removable casing is to be used. Ensure that drilled shaft concrete has a slump between 7 inches and 9 inches [175 mm and 225 mm] when placed and maintains a slump of 4 inches [100 mm] or more throughout the drilled shaft concrete elapsed time. Ensure that the slump loss is gradual as evidenced by slump loss tests described below. The concrete elapsed time is the sum of the mixing and transit time, the placement time and the time required for removal of any temporary casing that causes or could cause the concrete to flow into the space previously occupied by the temporary casing. Provide slump loss tests before drilled shaft concrete operations begin, demonstrating that the drilled shaft concrete maintains a slump of at least 4 inches [100 mm] throughout the concrete elapsed time. Inform the Engineer at least 48 hours before performing such tests.. Version 1.0-7/20/06 18

19 Slump Loss Test At least 3 yd 3 [2.3 m 3 ] and is mixed in a mixer truck. After initial mixing, determine the slump, temperature, and air content. Mix intermittently for 30 seconds every five minutes Determine slump, temperature, and air content at 30 minute intervals until the slump is 4 inches [100 mm] or less Drilled Shaft Concrete: Continued Perform the following procedures for slump loss tests: (1) Prepare the mix for the slump loss test at a temperature consistent with the highest ambient and concrete temperatures expected during actual concrete placement. Obtain the Engineer s approval of the test temperature. (2) Ensure that the mix is at least 3 yd3 [2.3 m3] and is mixed in a mixer truck. (3) After initial mixing, determine the slump, concrete temperature, ambient temperature and air content. Ensure that the concrete properties are within the required specification target limits. (4) Mix the concrete intermittently for 30 seconds every five minutes at the mixing speed of the mixer. (5) Determine slump, concrete temperature, ambient temperature and air content at 30 minute intervals until the slump is 4 inches [100 mm] or less. Remix the mix for one minute at the mixing speed of the mixer before these tests are run. (6) Begin all elapsed times when water is initially introduced into the mix. (7) Ensure that the concrete maintains a slump of at least 4 inches [100 mm] for the anticipated elapsed time. (8) Obtain the Engineer s approval of slump loss test results in terms of elapsed time before concrete placements. Version 1.0-7/20/06 19

20 Mass Concrete- Section Mass concrete is designated in the Contract Documents A Specialty Engineer or qualified technician will inspect and approve monitoring device placement & operation for each first placement of concrete by size & type 35 0 F differential max. When designing a Mass Concrete Mix, try to keep initial placing temps low Mass Concrete: When mass concrete is designated in the Contract Documents, provide an analysis of the anticipated thermal developments in the mass concrete elements for all expected project temperature ranges using the selected mix design, casting procedures, and materials..describe the measures and procedures intended for use to maintain a temperature differential of 35 F [20 C] or less between the interior core center and exterior surface(s) of the designated mass concrete elements during curing. Submit both the mass concrete mix design and the proposed mass concrete plan to monitor and control the temperature differential to the Engineer for acceptance. Provide temperature monitoring devices to record temperature development between the interior core center and exterior surface(s) of the elements in accordance with the accepted mass concrete plan..the Specialty Engineer, or a qualified technician employed by the Specialty Engineer, must personally inspect and approve the installation of monitoring devices and verify that the process for recording temperature readings is effective for the first placement of each size and type mass component. Submit to the Engineer for approval the qualification of all technicians employed to inspect or monitor mass concrete placements.. If the 35 F [20 C] differential has been exceeded, take immediate action, as directed by the Specialty Engineer who must be available for immediate consultation at any time, to retard further growth of the temperature differential. Version 1.0-7/20/06 20

21 Mass Concrete- Section Contractor must submit both the mass concrete mix design and the proposed plan to monitor and control the temperature differential concurrently to the Engineer for acceptance. Provide temperature monitoring devices to record temperature development between the interior core center and exterior surface(s) of the elements in accordance with the accepted mass concrete plan Mass Concrete: Continued..Describe the measures and procedures intended for use to maintain a temperature differential of 35 F [20 C] or less between the interior core center and exterior surface(s) of the designated mass concrete elements during curing. Submit both the mass concrete mix design and the proposed mass concrete plan to monitor and control the temperature differential to the Engineer for acceptance. Provide temperature monitoring devices to record temperature development between the interior core center and exterior surface(s) of the elements in accordance with the accepted mass concrete plan. Version 1.0-7/20/06 21

22 Composition of Concrete- Section Master Proportion Table Composition of Concrete Master Proportion Table: Proportion the materials used to produce the various classes of concrete in accordance with Table 3: Version 1.0-7/20/06 22

23 Chloride Content Limits- Section Ensure that the chloride content of all reinforced concrete produced does not exceed the maximum allowable limits indicated in Table 4. Sampling and Testing performed in accordance with Chloride Content Limits for Concrete Construction: General: Use the following maximum chloride content limits for the concrete application shown: Determine the chloride content as the average of three tests on samples taken from the concrete. Ensure that the range of results of the three tests does not exceed a chloride content of 0.08 lb/yd3 [0.05 kg/m3] of concrete. When test results are outside of the allowable range, run an additional three tests until the test results are within the allowable range. The Contractor may obtain samples from representative concrete cylinders or cores tested for compressive strength. If the cylinders or cores have been exposed to salt or aggressive environment, discard the outer 1 inch [25 mm] surface of the sample. This part of the specification is from the new proposed and accepted part of the 346 specification. Version 1.0-7/20/06 23

24 Chloride Content Limits- Section Certification: Certification for each mix design during mix design approval, as well as from the first day of production and every 30 calendar days or less thereafter Include in the certification all pertinent chloride test data that supports the concrete meeting this specification. The department will monitor the chloride content through comparison samples at a minimum frequency of one sample for each plant every twelve months Certification: Certify for each mix design during mix design approval, as well as from the first day of production and every 30 calendar days or less thereafter to the department that all reinforced concrete produced meets the requirement of this specification. Include in the certification all pertinent chloride test data that supports the concrete meeting this specification. The Department will require properly executed certifications showing the chloride content within the required limits for acceptance of all concrete produced in accordance with these Specifications. Include all the chloride certificates that apply with the monthly certification of compliance as required in section of these specifications. The department will monitor the chloride content through comparison samples at a minimum frequency of one sample for each plant every twelve months in accordance with section of the materials manual. Photograph of concrete piling with corrosion damage Version 1.0-7/20/06 24

25 Chloride Content Limits- Section Control Level for Corrective Action: If chloride test results exceed the limits of table 4, suspend concrete production immediately for every mix design using the same component materials.. If chloride test results are not obtained within 10 calendar days of concrete sampling, the engineer may suspend concrete production until corrective measures are made Control Level for Corrective Action: If chloride test results exceed the limits of table 4, suspend concrete production immediately for every mix design using the same component materials, including admixtures, until corrective measures are made. If chloride test results are not obtained within 10 calendar days of concrete sampling, the engineer may suspend concrete production until corrective measures are made. When the source of any component material, including admixtures, for the concrete is changed, sampling for chloride determination should restart the first day of production of the mix with the new component material. If chloride test results exceed the limits of table 4, reject all concrete from the last passing chloride test to the present or perform engineering analysis to demonstrate that the material meets the intended service life of the structure. This part of the specification is from the new proposed and accepted part of the 346 specification. Version 1.0-7/20/06 25

26 Chloride Content Limits- Section Control Level for Corrective Action:Continued When the source of any component material, including admixtures, for the concrete is changed, sampling for chloride determination should restart the first day of production of the mix with the new component material. If chloride test results exceed the limits of table 4, reject all concrete from the last passing chloride test to the present or perform engineering analysis to demonstrate that the material meets the intended Control Level for Corrective Action: If chloride test results exceed the limits of table 4, suspend concrete production immediately for every mix design using the same component materials, including admixtures, until corrective measures are made. If chloride test results are not obtained within 10 calendar days of concrete sampling, the engineer may suspend concrete production until corrective measures are made. When the source of any component material, including admixtures, for the concrete is changed, sampling for chloride determination should restart the first day of production of the mix with the new component material. If chloride test results exceed the limits of table 4, reject all concrete from the last passing chloride test to the present or perform engineering analysis to demonstrate that the material meets the intended service life of the structure. This part of the specification is from the new proposed and accepted part of the 346 specification. Version 1.0-7/20/06 26

27 Chloride Content Limits- Section Sampling and Testing Chloride testing in accordance with FM Concrete Type II w/ pozzolan(s) and prestressed (All other reinforced concrete where Type II not required, 1 test every four weeks) Chloride Content 0.25 lb/yd 3 (0.15 kg/m 3 ) or less during production >0.25 lb/yd 3 (0.15 kg/m 3 ) But less than or equal to 0.33 lb/yd 3 (0.20 kg/m 3 ) >0.33 lb/yd 3 (0.20 kg/m 3 ) Frequency Min. 1 every 4 weeks of production. If 8 consecutive <0.25 lb/yd 3,Eng. may reduce Min. 1 every 2 weeks of production. Min. 1 for each day s production Sampling and Testing: Determine the chloride content in accordance with FM within two weeks of sampling. (1) For all concrete requiring Type II cement with pozzolan(s) or slag and prestressed concrete, determine the chloride content on a frequency that is in accordance with these Specifications and the following procedures: (a) When the chloride content is 0.25 lb/yd3 [0.15 kg/m3] or less, determine chloride content at a frequency of not less than one for every four weeks of production as long as the test results remain at or below 0.25 lb/yd3 [0.15 kg/m3]. As an exception to the aforementioned testing frequency, when eight consecutive tests show chloride content below 0.25 lb/yd3 [0.15 kg/m3], the Engineer may reduce the frequency to not less than one for every eight weeks of production. (b) When the chloride content is greater than 0.25 [0.15] and less than or equal to 0.33 lb/yd3 [0.20 kg/m3], determine chloride content at a frequency of not less than one for every two weeks of production, as long as the values remain at or below 0.33 lb/yd3[0.20 kg/m3]. (c) When the chloride content is greater than 0.33 lb/yd3 [0.20 kg/m3], make subsequent chloride content tests for each day s production. (2) For all reinforced concrete, other than the concrete covered in (1) above, determine the chloride content on a frequency of not less than one test every four weeks. As an exception to the aforementioned testing frequency, when eight consecutive chloride content determinations are below 0.40 lb/yd3 [0.24 kg/m3] of concrete, the Engineer may reduce the frequency to not less than one for every eight weeks of production. For any case listed above, when the source of any concrete component material, including admixtures, is changed, determine the chloride content immediately. Test results obtained at the frequency provided above represent the chloride content of all concrete placed subsequent to the preceding test for the determination of chloride content. Version 1.0-7/20/06 27

28 Sampling & Testing- Section These are the * notes for the table above. *Use the same type of meter for QC tests as the Department uses for Verification testing. When using pressure type 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. ** For LOTs selected for verification testing use the same size cylinder molds as the Department uses for Verification tests. For the compressive strength testing of precast concrete the use of 4 inch x 8 inch [102 x 203 mm] test cylinders are allowed, provided they meet the requirements of Should you have Self-consolidating concrete on your project, refer to ASTM C 1611 and C 1621, for the proper test procedures. Version 1.0-7/20/06 28

29 Concrete Mix Design- Section Submit Mix Design prior to production Design for each class of concrete and combination of materials Use only approved Mix Designs Concrete Design Mix: Provide concrete that has been produced in accordance with a Department approved design mix, in a uniform mass free from balls and lumps. 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. Version 1.0-7/20/06 29

30 Concrete Mix Design- Section Version 1.0-7/20/06 30

31 Material Substitutions- Section Allows the Contractor to substitute material sources within a base mix design provided: Materials are the same type with similar chemical and physical characteristics Materials are from an approved source Provide a new base mix design for any cementitious material or admixture substitution At any time if the Engineer determines that unsatisfactory results are obtained, return to the originally approved base mix design Material Substitutions: Aggregate sources may be substituted within an approved base mix design provided that the aggregate are the same type, the same geological formation and are from an approved source. Obtain the Department s approval for any material substitutions before beginning concrete placement. Provide a new base mix design for any cementitious material or admixture substitution. For every material substitution made, perform testing for chlorides and assure compliance with Ensure the substituted mix meets the theoretical yield requirements, does not exceed the maximum water to cementitious materials ratio, and the cement content equals or exceeds, the approved base mix design. The Department may require a single 3.0 yd3 [2.3 m3] minimum test batch at the approved concrete production facility to demonstrate that the plastic properties of the adjusted mix design is within the slump and air tolerances provided in Table 2. The theoretical unit weight of the proposed mix design will be within 2.0 lbs/ft3 [35 kg/m3] of the originally approved theoretical mix design unit weight. At any time if the Engineer determines that unsatisfactory results are obtained during production, return to the originally approved base mix design or obtain approval of a new mix design. Version 1.0-7/20/06 31

32 Material Substitutions- Section Obtain the Department s approval 32 When preparing mix designs, you may not substitute any material in an existing FDOT approved Concrete Mix Design, without first obtaining the Department s approval. Version 1.0-7/20/06 32