305 SECTION 601 STRUCTURAL CONCRETE
601.1 -DESCRIPTION : This work shall consist of furnishing and placing portland cement concrete for structures, and incidental construction, in accordance with these specifications and in reasonably close conformity with the lines, grades and dimensions as shown on the Plans or established by the Engineer. All concrete shall be air -entrained. Classes of concrete shall be used as indicated below unless noted otherwise on the Plans: Class A concrete shall be used in railing, cribbing, precast shapes, and for filler. Class K concrete shall be used in all sidewalks, parapets, decks, and median barriers when they are a part of the bridge superstructure. Class B concrete shall be used in all beams and girders, roadway sidewalks, columns, hammerhead piers, arch rings including t ies and spandrel walls, rigid frames, box culverts, heavily reinforced abutments, retaining walls, footings, pedestals and other areas not specifically designated as to class of concrete. Class C concrete shall be used in massive footings and pedestals, m assive pier shafts, gravity walls and, in general, for non -reinforced or lightly reinforced concrete. Class D concrete shall be used as unformed and non -reinforced concrete for backfilling of any excavated pockets or voids on which footings are to be loca ted. Class H concrete shall be used for bridge decks and other bridge elements when designated in the plans. Class DC concrete shall be used in rock socketed drilled shafts. If the Contractor so elects, the Engineer may permit the use of a higher class concrete than the particular class designated for the work, in which event the higher class concrete shall meet the Specifications applicable without additional compensation. If the contractor uses a higher class concrete, and the strength specimens do no t meet the minimum strength requirement of that higher class concrete, no penalty will be applied, provided that the strength specimens exceed the minimum strength requirement of the concrete that was originally designated for the work. When called for on the Plans, an admixture of water -reducing retarder shall be added to all concrete so specified. A retarder may be used in other concrete at the Contractor's option. The work will be accepted in accordance with these Specifications and the applicable requirements of sections 105, 106, and 109. All classes of concrete shall be designated as modified when using increased design strengths. All classes of concrete shall be designated as architectural when using additional formwork as shown in Section 601.8.10. A hydration control stabilizing admixture may be used at the Contractor's option provided that the conditions in section 601.7 are met.
601.2 -MATERIALS : Materials shall meet the requirements specified in the following Sections or Subsections of Division 700:
306 Class H Concrete Requirements: The total concrete constituents shall contribute less than 0.10% water soluble chlorideion by weight of cement. The Contractor shall use only one brand and/or source for any concrete constituent. The Contractor shall obtain a written statement from the manufacturer of the silica fume admixture that confirms the compatibility of the material combination and t he sequence in which they are combined. The written statement, along with the results of all required tests, shall be furnished to the Engineer prior to the pre -pour meeting.
MATERIAL SECTION OR SUBSECTION Accelerating Admixtures 707.13 Air-Entraining Admixtures 707.1 Boiled Linseed Oil 711.2 Coarse Aggregate 703 Concrete Sealer 707.12 Curing Materials 707.6 -707.10 Epoxy Resin Protective Coating 707.11 Fine Aggregate** 702.1 Hydration Control Stabilizing Admixtures 707.15 Joint Filler (Substructure)**** 708.1.2 Joint Filler (Superstructure)***** 708.1.1 Petroleum Spirits (Mineral Spirits) 711.5 Portland Cement* 701.1, 701.3 Pozzolanic Additives*** 707.4 Specific Performance Admixtures 707.17 Supplementary Cementitious Materials (SCM)*** 707.4 Water 715.7 Water Reducer 707.3 Water -Reducing, Accelerating Admixtures 707.14 Water -Reducing, Set -Retarding Admixtures 707.2
* It is normally intended that the product of only one mill or of any one brand or type of Portland cement be used on any one structure. ** Only siliceous sand shall be used as fine aggregate in bridge deck wearing surfaces. *** The use of a Supplementary Cementitious Material (SCM) will not be permitted when a blended hydraulic cement is used. For the purposes of cement material substitution with SCMs, Type IL cement shall not be treated as a blended cement, and a SCM may be used with Type IL cement. Unless otherwise permitted by the Engineer, only one source of a SCM shall be used in any one structure. **** Joint filler for vertical joints in the substructure shall be in accordance with Section 708.1.2. ***** Preformed joint filler for vertical joints in the superstructure shall be sponge rubber in accordance with Section 708.1.1.
Shipping and Storage of Cement: Cement shall be shipped from pretested and approved bins at the mill or distribution terminals. Cement stored by the Contractor for a period longer than 90 days shall be retested before being used in the work. Cement failing to meet any of the specifie d requirements at any time prior to incorporation into the work will be rejected and shall be removed from the work. Cements of different brands, types, or from different mills shall be stored separately.
307 Shipping and Storage of SCMs: SCMs shall be shi pped from only those sources approved by the Division. Bulk SCMs shall be stored at the job site in weatherproof bins. SCMs from different sources or from different lots at the same source shall be stored separately.
CONSTRUCTION METHODS
601.3 -PROPORTIONING : The proportions for any concrete designated as modified shall be submitted by the Contractor to the Engineer for approval. The Design 28 -Day Compressive Strength shall be as shown in the plans . The contractor’s mix design shall utilize Table 601.3.1, except the Target Cement Factor may be revised to obtain the modified strength. Class H concrete shall consist of a homogeneous mixture of cement, fine aggregate, coarse aggregate, silica fume adm ixture, fly ash or slag cement, chemical admixtures, and water. Establishment of mixture proportions shall be coordinated with the manufacturer of the silica fume admixture. Design mixture testing for Class H concrete shall be in accordance with MP 711.0 3.23 and shall include air content, slump, compressive strength, and rapid chloride permeability tests. For establishment of mixture proportions, rapid chloride permeability tests shall be made on representative samples prepared and tested in accordance with AASHTO T 277. The rapid chloride permea bility test specimens shall be tested at an age of 90 days (or at any time prior to 90 days), and the results of this test shall not exceed 750 coulombs. Specimens shall be moist cured for 56 days prior to the start of specimen preparation unless specimens are to be tested prior to 56 days, in which case the specimens shall be moist cured until the time of test. The 28 -day compressive strength of the test mix that satisfies the 750 coulomb threshold shall be used as the basis for acceptance of Class H con crete per Section
601.4.5The cost of all test mix requirements shall be considered incidental to the cost of Class H
concrete. For establishment of mixture proportions, as an alternative to the curing methods for rapid chloride permeability testing outl ined in the previous paragraph, specimens may be moist cured for 7 days in accordance with ASTM C192, then cured for 21 days in lime -saturated water at 100.0 ± 3.5 °F, then tested at an age of 28 days. This method of curing shall be noted as the accelerated RCPT curing method.
601.3.1 -Mix Design Requirements: Prior to the start of construction, the Contractor shall design and submit to the Engineer for approval the proportion of materials, including admixtures, to be used which will result in a workabl e concrete having the applicable properties enumerated below, including those of Table 601.3.1A. A mix design prepared in accordance with MP 711.03.23, shall be required for each class of concrete to be used in the work. The mix design shall be accompanied by a statement giving the source of materials and certified test data from a Division approved laboratory demonstrating the adequacy of the mix design. The Contractor shall notify the Engineer of any change in the source of materials or the addition of admixtures during the progress of the work, since such change may necessitate a new mix design. The Contractor shall also state the Ā value of the fine aggregate and the Ā value of the combined grading of the coarse aggregate, fine aggregate, and cement used in the mix design. Each mix design shall remain approved for a period of three years from the date of approval, after which the mix design may be re -approved for an additional time period. The guidelines for this re -approval process are set forth in MP 711.03.23. Approved Hydration Control Stabilizing Admixtures, as defined in Section 707.15, which are designed to stop the hydration of cement in a concrete mix, enabling an extension to the
308 allowable discharge time from a truck mixer as outlined in Section 601.7, may be added to an existing approved concrete mix design in accordance with the procedures outlined in MP 711.03.23.
TABLE 601.3.1A Class of Concrete Design 28 Day Compressive Strength Target Cement Factor Maximum Water Content Standard Size of Coarse Aggregate*** Entrained Air Pounds per Square inch lbs./c.y.* lb. of water / lb. of cement ** Number Percent A 3500 682 0.51 7, 78, or 8 7.5 K 4000 658 0.44 57, 67 7.0 B 3000 564 0.49 57, 67 7.0 C 2500 494 0.58 57, 67 6.0 D 2000 400 0.62 57, 67 5.5 H 4000 See Table 601.3.1C 0.40 57,67 6.5 DC 4500 705 0.44 7, 78, 8 6.0
* An equal mass of a SCM may be substituted for Portland cement up to the maximum amount in Table 601.3.1B. Only one SCM is permitted in a mix design, except for Class H concrete. The target cement factor of Class H concrete shall consist of Option 1 or Option 2 from Table 601.3.1C. The Contractor may choose either option. ** When using a SCM, masses of these materials shall be considered as cem ent for purposes of establishing maximum water content. *** A number 67 coarse aggregate may be used in Class DC concrete, provided the Engineer approves the use of that size aggregate for the specific project on which it is to be used. That approval will depend on the minimum spacing of the reinforcing steel in the drilled shaft foundation.
TABLE 601.3.1B Material Class of Concrete Quantity Fly Ash All Classes Except H 20% Slag Cement All Classes Except H 50% Silica Fume All Classes Except H 8%
TABLE 601.3.1C Option Cement Fly Ash Slag Cement Silica Fume 1 470 lbs. 132 lbs. 30 lbs. 2 423 lbs. 195 lbs. 30 lbs.
MP 711.03.26 shall be used to control the cement factor in all classes of concrete except Class H. The Contractor may develop mix designs with a reduced target cement factor as indicated in Table 601.3.1D in lieu of Table 601.3.1A, provided the aggregates used in those mix designs meet the requirements for optimized aggregate gradation in Section 601.3.2.4. 1. The Ā requirements will not apply for mix designs that use optimized aggregate gradation.
309 TABLE 601.3.1D Class of concrete Design 28 Day Compressive Strength Target Cement Factor Maximum Water Content Nominal Maximum Aggregate Size Entrained Air Pounds per Square inch lbs./c.y. Note 1 lb. of water/lb. of cement Note 2 Inches Percent A 3500 642 0.51 ½ 7.5 K 4000 618 0.44 1 7.0 B 3000 524 0.49 1 7.0 C 2500 454 0.58 1 6.0 D 2000 360 0.62 1 5.5 H 4000 See Table 601.3.1E 0.40 1 6.5 DC Note 3 4500 665 0.44 ½ 6.0
Note 1 An equal mass of a SCM may be substituted for Portland cement up to the maximum amount in Table 601.3.1B. Only one SCM is permitted in a mix design, except for Class H concrete. The target cement factor of Class H concrete shall consist of Option 1 or Option 2 from Table 601.3.1E. The Contractor may choose either option. Note 2 When using a SCM, masses of these materials shall be considered as cement for purposes of establishing maximum water content. Note 3 Nominal maximum aggregate size of 3/4 inches may be used in Class DC concrete, provided the Engineer approves the use of that size aggregate for the specific project on which it is to be used. That approval will depend on the minimum spacing of the reinforcing steel in the drilled shaft found ation.
TABLE 601.3.1E Option Cement Fly Ash Slag Cement Silica Fume 1 440 lbs. 127 lbs. 25 lbs. 2 397 lbs. 186 lbs. 25 lbs.
601.3.1.1 -Mix Design Using Potentially Reactive Aggregate: Alkali -Silica Reaction
forms of silica in the aggregate. The reaction forms a gel that swells when moisture is present and may cause deleterious expansion within the co ncrete. The Division will sample aggregate according to MP 700.00.06 and test fine aggregate and coarse aggregate in accordance with AASHTO T 303 to determine the reactivity class of aggregate. The reactivity class for each aggregate source will be liste d on the MCS&T web page under Division Approved Source/Product Listing (APL) for aggregate. If the reactivity class of an aggregate Source is not listed on the APL, the Division will test fine and coarse aggregate from the Source, in accordance with AASHTO T 303, to determine the reactivity class of the aggregate prior to its use on any WVDOH project. If one or both of the aggregates (coarse or fine) used in a concrete mix are reactive (R1, R2 or R3), preventive measures are required as specified in section 601.3.1.1.1.4. The Division will test Aggregate Sources on a 3 -year cycle in accordance with AASHTO T 303. Aggregate Suppliers may have their fine aggregate and coarse aggregate tested in accordance with ASTM C1293 at a Division approved lab (an AASHTO accredited Lab, accredited for ASTM C1293) at the Aggregate Supplier’s expense. The sampling and shipping of a ll aggregate shall be witnessed by a representative of the Division. Aggregate
310 Suppliers may also submit results of ASTM C1293 tests which were performed by another State DOT lab. The results of ASTM C1293 testing and the resulting determination of the reactivity class of aggregate shall supersede the reactivity class of aggregate, as determined by the Division, when tested in accordance with AASHTO T 303. ASTM C1293 test will be considered valid for 5 years from the date of testing. This requirement appl ies to all permanent concrete structures on WVDOH projects.
601.3.1.1.1 -Selecting Preventive Measures For ASR: The level of prevention shall be determined by considering the classes of concrete, precast concrete member, prestressed concrete member, the degree of aggregate reactivity and the level of alkalis from the Portland cement. The different levels of prevention are shown in Table 601.3.1.1.1.3.
601.3.1.1.1.1 -Aggregate Reactivity: The degree of ASR reactivity of an aggregate will be determined a s outlined in 601.3.1.1. Aggregate -reactivity classes are given in Table 601.3.1.1.1.1 If the coarse and fine aggregates in a mix design are of different reactivity classes, the level of prevention shall be selected for the most reactive aggregate type in the mix. TABLE 601.3.1.1.1.1 Classification of Aggregate Reactivity Aggregate - Reactivity Class Description of Aggregate Reactivity 14-Day Expansion when tested in accordance with AASHTO T 303, % 1-Year Expansion when tested in accordance with ASTM C1293 R0 Non-Reactive ≤ 0.10 ≤ 0.04 R1 Moderately Reactive > 0.10 to ≤ 0.30 > 0.04 to ≤ 0.12 R2 Highly Reactive > 0.30 to ≤ 0.45 > 0.12 to ≤ 0.24 R3 Very Highly Reactive > 0.45 > 0.24
601.3.1.1.1.2 -Level of ASR Risk: Determine the level of ASR risk occurring in a structure by considering the aggregate reactivity class in Table 601.3.1.1.1.2.
601.3.1.1.1.3 -Level of Prevention: The level of prevention required is determined from Table 601.3.1.1.1.3 by considering the risk of ASR from Table 601.3.1.1.1.2 in different classes of concrete, precast concrete member and prestressed concrete member (Section 603). TABLE 601.3.1.1.1.2 Aggregate - Reactivity Class R0 R1 R2 R3 Level of ASR Risk Risk Level 0 Risk Level 1 Risk Level 2 Risk Level 3
311 TABLE 601.3.1.1.1.3 Determining the Level of Prevention Level of ASR Risk Classes of Concrete Precast Concrete Member Prestressed Concrete Member D A, B, C, K, H, DC Risk Level 0 V V V Risk Level 1 W X Y Risk Level 2 X Y Z Risk Level 3 Y Z See footnote** ** It is not permitted to construct prestressed concrete members (Section 603) with Aggregate Reactivity Class of R3. Measures must be taken to reduce the level of risk in these circumstances by selecting the aggregates only from the Reactivity Classes of R0, R1, or R2.
601.3.1.1.1.4 -Requirements for Various Prevention Levels: These requirements shall apply to all classes of concrete except Class H. The prevention levels for Class H concrete is specified in section 601.3.1.1.1.5.
601.3.1.1.1.4.1 -Prevention Level V: No special measures need to be taken for prevention level V.
601.3.1.1.1.4.2 -Preventions Level W, X and Y : If it is determined that prevention level W, X, or Y is required, there are two options for prevention as fo llows:
Option 1: Limiting the Alkali Content of the Concrete: Table 601.3.1.1.1.4.2a prescribes maximum permissible concrete alkali contents in a concrete mix. The alkali content of concrete is calculated on the basis of the alkali contributed by the Portland cement alone.
TABLE 601.3.1.1.1.4.2a Maximum Alkali Con tents in Portland Cement Concrete to Provide Various Levels of Prevention Prevention Level Maximum Alkali Content of Concrete (Na₂Oe) lb/yd³ V No limit W 5.0 X 4.0 Y 3.0
Note: The alkali content of the concrete is calculated by multiplying the Portland cement content of the concrete by the alkali content of the Portland cement. The alkali content of all approved cement sources is listed on the WVDOH list of Certified PortlandCe ment Mills. For example, for concrete containing 550 lb/yd³ of Portland cement, which has an alkali content of 0.82 percent Na₂Oe, the alkali content of the concrete is 550 X 0.82/100 = 4.51 lb/yd3 Na₂Oe. SCMs also contain alkalis; however, the use of SCM usually increases the amount of alkalis bound by the hydrates and thus reduces the available alkali content in the concrete. Thus, the alkalis present in SCMs do not need to be considered when calculating the alkali content of the concrete. However, the a lkali content of the SCM shall not exceed the limits given in Table 601.3.1.1.1.4.2b. The alkali content of all approved SCM source is listed on the WVDOH approved list of SCMs.
312 Option 2: Using Minimum Supplementary Cementitious Materials (SCM) based on Level of Prevention. Utilize a minimum mass replacement level from Table 601.3.1.1.1.4.2b below. TABLE 601.3.1.1.1.4.2b Minimum Replacement Level of SCM (percentage by mass of cementitious material) Type of SCM Alkali Content of SCM* (Na 2Oe) Level W Level X Level Y Fly ash** (Cao ≤18%) ≤3.0 15 20 25**** >3.0, ≤4.5 20 25**** Not Allowed Slag Cement ≤1.0 25 35 50 Silica Fume*** ≤1.0 1.2 x LBA 1.5 x LBA 1.8 x LBA
* The alkali content of all approved SCM sources is listed on the WVDOH approved list of SCMs (APL). If the alkali content of an SCM source is not listed on the APL, the Division will test the SCM from the source to determine the alkali content prior to its use on any WVDOH project.
** The CaO content of approved fly ash sources is listed on the WVDOH approved list of fly ash (APL). If the CaO content of a fly ash source is not listed on the APL, the Division will test the fly ash from the source to determine the CaO content prior to its use on any WVDOH project.
*** The minimum level of silica fume (as a percentage by mass of cementitious material) is calculated on the basis of the alkali (Na₂Oe) content of the concrete contributed by the Portland cement and expressed in lb/yd³ (LBA in Table 601.3.1.1.1.4.2b). LBA is calculated by multiplying the cement content of the concrete in lb/yd³ by the alkali content of cement divided by 100. For example, for a concrete containing 500 lb/yd³ of cement with an equivalent alkali content of 0.81 percent of Na₂Oe, the value of LBA = 500 x 0.81/100 = 4.05 lb/yd³. For this concrete, the minimum replacement level of silica fume for Level Y is 1.8 x 4.05 = 7.3 percent. Regardless of the calculated value , the minimum level of silica fume shall not be less than 7 percent when it is only method of prevention. Mix design with silica fume > 8% shall be reviewed and approved by the Engineer.
**** Mix designs with minimum 25% of fly ash shall be reviewed and approved by the Engineer.
Note: The minimum replacement levels in Table 601.3.1.1.1.4.2b are appropriate for use with Portland cements of moderate to high alkali contents (0.71 to 1.00 percent Na₂Oe). Table 601.3.1.1.1.4.2c provides recommendations for adjusting the level of SCM when the equivalent alkali content of the Portland cement is above or below this range. The replacement levels should not be below those given in Table 601.3.1.1.1.4.2b for prevention level W, regardless of the equivalent alkali content of the Portland cement.
TABLE 601.3.1.1.1.4.2c Adjusting the Minimum Level of SCM Based on the Alkali Content of the Portland Cement Alkali Content (Na₂Oe)* Level of SCM ≤0.70 Reduce the minimum amount of SCM required in Table 601.3.1.1.1.4.2b by one prevention level.* * >0.70, ≤1.00 Use the minimum levels of SCM required in Table 601.3.1.1.1.4.2b >1.00, ≤1.25 Increase the minimum amount of SCM required in 601.3.1.1.1.4.2b by one prevention level. >1.25 Not permitted to be used in PCC
* The alkali content of all approved cement sources is listed on the WVDOH list of Certified Portland Cement Mills (APL). If the alkali content of a cement source is not listed on the APL, the Division will test the cement from the source to evaluate alkali content prior to its use o n any WVDOH project.
** The SCM replacement levels should not be below those required in Table 601.3.1.1.1.4.2b for prevention level W, regardless of the equivalent alkali content of the Portland cement.
313 Option 3: Using the Lithium Nitrate Admixture: The 30 percent (30%) aqueous solution of Lithium Nitrate Admixture meeting the requirements of Section 707.17 shall be used for all level of prevention including “Level Z” given in Table 601.3.1.1.1.3 except for Class H concrete. The dosage rat e of Lithium Nitrate Admixture shall be based upon the alkali content of cement used in a concrete mix. Calculation of lithium nitrate (LiNO 3) admixture dosage (100 percent) for mitigation without use of SCMs with a 30 percent (30%) aqueous solution of l ithium nitrate.
Gallons of LiNO 3/yd3 = (A x B x 0.55)/100 Where: A = Pound of Portland cement per cubic yard in a concrete mix B = Percentage of A lkali content of cement used in a concrete mix
Example: If the cement content of concrete is 550 lbs/yd3 and the total alkali content of the cement is 0.82 percent (0.82%) , the dosage of lithium nitrate admixture is: (550 x 0.82 x 0.55)/100 = 2.48 Gal/yd3.
The water content of the mix shall be adjusted by removing 0.85 gallons of water per gallon of lithium nitrate solution.
Example: Amount of water to be reduced (using the value from above example) Gal/yd3 = 0.85 x 2.48 = 2.11
Any concrete mix using a 100 percent (100%) lithium nitrate admixture dosage will be accepted without evaluation. The contractor shall evaluate the effectiveness of less than 100 percent (100%) lithium nitrate admixture in a concrete mix, alone or in combination with fly ash or slag cement or silic a fume , in the reduction of expansion in accordance with ASTM C1567*, when a reactive aggregate(s) is (are) used in a concrete mix, at a Division approved lab (an AASHTO accredited Lab, accredited for ASTM C1567) at the contractor’s expense. The dosage rat e shall not be less than 50 percent (50 %) when only a lithium nitrate admixture is using for evaluation and no SCMs are included in the concrete mix. The sampling and shipping of all aggregate shall be witnessed by a representative of the Division. The A STM C1567 test results will be considered valid for 5 years from the date of testing. If both of the aggregates (coarse and fine) used in a concrete mix are reactive (R1, R2 or R3), the contractor shall evaluate the effectiveness of the lithium nitrate ad mixture , alone or in combination with fly ash or slag cement or silica fume for both of the aggregates separately. When the same source material** is proposed for the use both as coarse and as fine aggregate, test only a selection of the reactive fine aggr egate or reactive coarse aggregate, unless there is reason to expect that the coarse aggregate has a different composition than the fine aggregate or vice -versa. The combination of cement, lithium nitrate admixture , alone or in combination with fly ash or slag cement or silica fume, and aggregate that expands less than 0.10% at 16 days after casting will be considered as meeting the “Requirements for Various Prevention Levels (Section 601.3.1.1.1.4)” except for Class H concrete. The approved lithium nitra te admixture shall meet the requirements of Section 707.17 and will be listed as “TypeS” admixture with footnote of approved admixture for ASR mitigation on the MCS&T web page under Division Approved Source/Product Listing
314 (APL) for TypeS: Special Perfor mance. The alkali level of fly ash used in the subject mix shall not exceed 4.5%. The alkali level of slag cement used in the subject mix shall not exceed 1.00%. The alkali level of silica fume used in the subject mix shall not exceed 1.00%. Mix design sha ll be reviewed and approved by the Engineer.
* Modify the w/c ratio of the mortar used in the ASTM C1567 test to 0.50.
Replace Section 5.3 (Sodium Hydroxide Solution) of ASTM C1567 with the following: Sodium Hydroxide Solution - Each liter of solution shall contain 40.0 g of NaOH dissolved in 800 ml of water. Add 71 ml of the lithium nitrate admixture multiplied by the decimal equivalent of the lithium nitrate admixture dosage. (For example, to test a 75% lithium nitrate admixture dosage, each liter of solution will contain 0.75 times 71 ml of lithium nitrate admixture.) This mixture shall be diluted with additional distilled or deionized water to obtain 1.0 liter of solution. The volume proportion of soaking solution to mortar bars in a storage container shall be 4 ± 0.5 volumes of solution to 1 volume of mortar bars. The volume of a mortar bar may be taken as 184 ml. Include sufficient test solution to ensure complete immersion of the mortar bars.
** Same source material applies to same Limes tone, Diabase, Quartzite and Basalt source.
601.3.1.1.1.4.3 -Prevention Level Z: If it is determined that prevention level Z is required, limit the maximum alkali content of concrete to ≤ 3.0 lb/yd3 plus use the minimum SCM replacement level shown for level Y in Table 601.3.1.1.1.4.2b. The mix design for Prevention Level Z shall be re viewed and approved by the Engineer.
601.3.1.1.1.5 -Requirements for Various Prevention Levels for Class H Concrete: 601.3.1.1.1.5.1 -Prevention Level V: No special measures need to be taken for prevention level V.
601.3.1.1.1.5.2 -Prevention Level X: The contractor may choose Option 1 or Option 2 from Table 601.3.1C. The alkali content of cement shall not exceed 1.25%. The alkali level of fly ash shall not exceed 4.5% in option 1. The CaO of the fly ash must be limited to a maximum of 18% in option 1. The alkali level of slag cement shall not exceed 1.00% in option 2. The alkali level of silica fume shall not exceed 1.00% in option 1 and option 2.
601.3.1.1.1.5.3 -Prevention Level Y: The contractor may choose Option 1 or Option 2 from Table 601.3.1C if the alkali content of cement does not exceed 1.00%. The alkali level of fly ash shall not exceed 4.5% in option 1. The CaO of the fly ash must be limited to a maximum of 18% in option 1. The alkali level of slag cement shall not exceed 1.00% in option 2. The alkali level of silica fume shall not exceed 1.00% in option 1 and option 2.
601.3.1.1.1.5.4 -Prevention Level Z: The contractor may choose Option 1 from Table 601.3.1C if the alkali content of cement does not exceed 1.00% and the alkali level o f fly ash does not exceed 3.00%. The contractor may also choose Option 1 from Table 601.3.1C if the alkali content of cement does not exceed 0.85% and the alkali level of fly ash does not exceed 4.5%. The CaO of the fly ash must be limited to a maximum of 18%. The contractor may choose Option 2 from Table 601.3.1C if the alkali content of cement does not exceed 0.85%. The alkali level of slag cement shall not exceed 1.00%. The alkali level of silica fume shall not exceed 1.00% in option 1 and option 2.
315 601.3.1.1.1.6 -Evaluation of the effectiveness of SCM to prevent deleterious expansion: The contractor may evaluate the effectiveness of an SCM in the reduction of expansion in accordance with ASTM C1567*, when a reactive aggregate(s) is (are) used in a c oncrete mix, at a Division approved lab (an AASHTO accredited Lab, accredited for ASTM C1567) at the contractor’s expense. The sampling and shipping of all aggregate shall be witnessed by a representative of the Division. ASTM C1567 test will be considere d valid for 5 years from the date of testing. If both of the aggregates (coarse and fine) used in a concrete mix are reactive (R1, R2 or R3), the contractor shall evaluate the effectiveness of SCM for both of the aggregates separately. When the same sourc e material** is proposed for the use both as coarse and as fine aggregate, test only a selection of the reactive fine aggregate or reactive coarse aggregate, unless there is reason to expect that the coarse aggregate has a different composition than the fi ne aggregate or vice -versa. The combination of cement, SCM and aggregate that expand less than 0.10% at 16 days after casting will be considered as meeting the “Requirements for Various Prevention Levels (Section 601.3.1.1.1.4)” except for Class H concret e. The evaluation with the higher percentage of SCM replacement shall be selected for the minimum replacement level of SCM for prevention level in a mix design using potentially reactive aggregate. When more than one mix design, for the same Producer/Sup plier, is submitted for evaluation, only one evaluation of the effectiveness of an SCM in the reduction of expansion in accordance with ASTM C1567 testing data, as outlined in paragraphs first through four of this sub -section, will be required for that ent ire group of mix designs (except Class H) if all of the mix design in that entire group of mix designs have the same combination of cement, SCM and aggregate sources. The alkali level of fly ash shall not exceed 4.5%. The alkali level of slag cement shall not exceed 1.00%. The alkali level of silica fume shall not exceed 1.00%. Mix designs with minimum 25% of fly ash shall be reviewed and approved by the Engineer. Mi x design with silica fume > 8% shall be reviewed and approved by the Engineer.
* Modify the w/c ratio of the mortar used in the ASTM C1567 test to 0.50. ** Same source material applies to same Limestone, Diabase, Quartzite and Basalt source.
601.3.2 -Field Tolerances and Adjustments: 601.3.2.1 -Consistency: Concrete shall have the consistency which will allow proper placement and consolidation in the required position. Every attempt shall be made to obtain a uniform consistency. The optimum consistency for various types of highway structures shall be as indicated in Table 601.3.2. Concrete for any “Slump Test” shall be deposited in a manner and location that excludes the effects of vibrations caused by traffic and concrete placement operatio ns. An approved Type F or Type G admixture may be used to increase the consistency and improve the workability of the concrete as long as the requirements of section 707.2.2.1 or to as a superplasticizer. No more than a total of two additions of a superplasticizer shall be permitted in any one batch of concrete. If a superplasticizer is used at the batch plant, then only one field addition is permitted. The total quantity of the superplasticizer shall not exceed the manufacturer’s recommended dosage rate.