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.
316 Upon addition of a superplasticizer at the job site, the mixing drum shall be turned for a minimum of 60 revolutions or 5 minutes at mixing speed to establish a workable mixture of uniform composition and consistency. If a second job site addition of superplasticizer is used; the mixing drum shall be turned a minimum of 30 additional revolutions at mixing speed. All additions and mixing of the superplasticizers hall be completed before placement of the concrete is started. The total number of revolutions shall not exceed 300, and the concrete shall be discharged within the time limits in section 601.7. The slump of Class H concrete shall not exceed seven ( 7) inches under any circumstances. When a superplasticizer is used, the optimum consistency target value may be increased by four ( 4) inches, but under no circumstances shall the slump exceed eight ( 8) inches. Acceptance tests for consistency (slump), air con tent, compressive strength, etc. shall be made after all additions and mixing of the superplasticizer. Slump tests shall be performed on every batch of concrete to which superplasticizer is added (one test before and one test after the addition of superpl asticizer). The Contractor shall obtain a written statement from the manufacturer of the superplasticizer stating:
materials and the sequence in which they are combined. ii. The recommended maximum admixture dosage rate. iii. Immediately after mixing, the air content and slump shall be measured by a certified Portland Cement Concrete Inspector.
This written statement from the admixture manufacturer shall be made available to project personnel before any superplasticizer is added at the job site.
317 TABLE 601.3.2 CONSISTENCY
TYPE *Optimum Consistency Inches of Slump
concrete gutters, cast in place concrete slope protection, etc., requiring low slump concrete to allow proper placement and consolidation and the maintenance of the prescribed geometry; those structures which are placed by slip form construction methods where a low slump is required to m aintain the prescribed geometry; and mass nonreinforced concrete. 1 inch ii. For reinforced concrete structures which are sufficiently massive and generally have sufficient clearances to allow the access of workers into the immediate area of concrete placement, such as bridge piers, column and abutment footings; piers, large columns, and other similar type structures into which workers may enter for the purpose of placing and consolidating the concrete. 2 inches iii. a. For reinforced concrete structures which are not easily accessible for spading and vibrating and offer a fair degree of difficulty in the placement and consolidation of the concrete, such as pier caps and abutments, beams and girders, box culverts, miscellaneous structur e footings and other slab type structures, wall or vertical sections 8 inches or greater in width with one line of reinforcement or 12 inches or greater in width with two lines of reinforcement. 3 inches
iv. For structures which are inaccessible to workers and generally offer a considerable degree of difficulty in the placement and consolidation of the concrete, such as long slender columns and thin-walled 3 ½ sections less than 8 inches thickness. 3 ½ inches
concreting must be done, such as structural steel encasement; other special structures which contain small openings through which the concrete must pass; tremie concrete which must be placed a nd consolidated into all spaces without mechanical disturbances; and other special structures which would require high consistency concrete for proper placement and consolidation. **
* If the consistency exceeds the target value plus one inch, the Contractor shall take immediate steps to reduce the slump of succeeding loads by making necessary adjustments in the mixture. The Contractor will be allowed a reasonable time for the trucks alrea dy on the road for a central mix or truck mix operation. Failure to comply will be cause for rejection of the concrete. If the consistency exceeds the target value plus 1 ¾ inches, the concrete will be rejected. ** The optimum consistency shall be that co nsistency which will allow a proper placement and consolidation of the concrete into all spaces.
318 601.3.2.2 -Air Content: The target value of the entrained air at the point of placement shall be as shown in Table 601.3.1A. If the entrained air does not conform with the target value within plus or minus 2.5 percentage points, the Contractor shall take immediate steps to adjust the air content of succeeding loads by making necessary adjustments in the mixture. The air content shall be measured on loads already batched and enroute, as well as the first load to which any adjustments were made in batching procedures. If the air content exceeds the target value plus 3.0 percentage points the concrete shall be rejected. When the concrete is delivered in a truck mixer and the air content is less than the target value minus 2.5 percentage points the concrete shall be rejected, or the Contractor may use additional air entraining agent in an amount that is intended to achieve the target value specified. The a ddition is permitted under the conditions listed below. The target of the entrained air content of Class H concrete at the time of placement shall be as shown in Table 601.3.1A. If the entrained air does not conform with the target value within plus or minus 1.5 percentage points, the Contractor shall take immediate steps to adjust the air content of succeeding loads by making necessary adjustments in the mixture. If the entrained air content of Class H concrete does not conform to the target value plus 2.0 percentage points, the concrete shall be rejected. When Class H concrete is delivered in a truck mixer and the air content is less than the target value minus 2.0 percentage points, the concrete shall be rejected or the Contractor may use additional a ir-entraining agent in an amount that is intended to achieve the target value specified. The addition is permitted under the conditions listed below.
thoroughly mixed with a mi nimum of 2 gallons of water. The solution will be directed to the front of the mixer. ii. The mixer is turned a minimum of 30 revolutions, at mixing speed, or the number of revolutions established in tests to comply with uniformity requirements, whichever is more.
Immediately after mixing, the air content and slump shall be measured by a certified inspector or technician. An air adjustment may be attempted twice per truck. If after the second addition the specified air content is not achieved, the concrete shall be rejected. These procedures do not alter the limits placed on time to discharge, the total revolutions of the mixing drum, or the specified slump.
601.3.2.3 -Yield: The approved mix design shall be subject to modification under the cond itions prescribed. After the start of the first concreting operation and immediately after the specified consistency and entrained air have been established, three unit weight determinations shall be made from different batches and the average of the thre e determinations shall be considered the unit weight of the concrete. The actual yield shall be determined from the average unit weight. The design mix shall be adjusted as required to correct the actual yield to correspond to the theoretical. During th e progress of the work, the actual yield shall be verified at the frequency noted in MP 601.03.50; and, if the yield, based on a single unit weight determination, should differ from the theoretical yield by more than plus or minus two percent (2%) , two additional unit weight determinations shall be made, and the average of the three determinations shall be considered the unit weight of the concrete. The actual yield shall
319 be determined from that average unit weight, and the design mix shall be adjusted as required to correct the actual yield to correspond to the theoretical yield. The Division shall perform Yield tests randomly throughout the progress of work to verify the accuracy of the Contractor’s tests. In addition to the mix design adjustments spec ified above to correct for yield, other adjustments in the design mix proporti ons shall be made as necessary to maintain a plastic, workable mix with suitable finishing characteristics. No change in the brands or sources of material shall be made without prior approval of the Engineer. Methods for determining -the properties enumerated above shall be in accordance with 601.4.
601.3.2.4 -Total Solids Ā: The combined grading of the coarse aggregate, fine aggregate, and cement used in the structural concrete shall conform to the design mix Ā plus or minus the tolerance specified in the following table for the coarse aggregate size used. This subsection will not apply for mix designs with optimized aggregate gradation. Subsection 601.3.2.4. 1 shall be used in lieu of subsection 601.3.2.4.
TABLE 601.3.2.4 -Total Solids Ā Coarse Aggregate Size Number Design Mix Ā Tolerance 3 or 4 0.35 57 or 67 0.25 7, 78 or 8 0.15
Ā is the value obtained by grading of the total solids (coarse aggregate, fine aggregate, and cement). The Ā shall be determined by the Contractor (in accordance with MP 601.03.51) at least once for every 50 cubic yards of concrete that are produced from the same mix design. However, not more than one Ā test (for each mix design) shall be required per calendar day as long as not more than 400 cubic yards of concrete are produced in a single day from the same mix design. In situations when more than 400 cubic yards of concrete are produced in a single day fro m the same mix design, two Ā tests shall be required (one in the AM and one in the PM) for that mix design. During any calendar week (Sunday through Saturday) in which concrete is being produced, a minimum of one Ā test shall be required (for each mix des ign from which concrete is being produced). This Ā test shall be conducted on the first day of production of that calendar week. For days on which concrete is being produced, but no Ā test is required, laboratory number 1392885 shall be used for Ā test d ocumentation purposes. Should the moving average of any five consecutive grading tests of the total solids have an Ā outside the specified mix design tolerance limits, production shall be discontinued until appropriate corrections are made. Corrections shall be made either in the proportions of the concrete (the mix design), the gradation of the aggregates, or the storage and loading of the aggregate, as the Contractor may elect. When the small quantity work condition applies, the Ā required after 50 cubic yards of concrete production shall be performed on the day that the 50 cubic yard quantity is achieved. All concrete produced on that day (the day that the 50 cubic yard quantity is achieved) shall be represented by the previous Ā. The Ā conducted on the day that the 50
320 cubic yard quantity is achieved shall represent the next 50 cubic yards of concrete produced, beginning with the concrete produced on the next day of production. When, in a concrete mix, gradations tests show that the pe rcentage of material which passes the No. 200 (75 µm) sieve, exceeds the amount permitted in Sections 702.1.2 and 703.4, and provided the Engineer permits the material to remain in place and the Contractor elects to leave the material in place, then a pena lty shall be applied in the manner outlined in the following paragraph. It shall be determined which material (coarse aggregate, fine aggregate, or both) caused the total material finer than the No. 200 (75 µm) sieve to exceed the specification limits as determined in Sections 702.1.2 and 703.4. The mass of the material(s) in the concrete mix (Mca, Mfa, or both, as defined in MP 601.03.51), which caused the total material finer than the No. 200 (75 µm) sieve to exceed the specification limits shall be divided by M t (as defined in MP 601.03.51). The resulting number shall be multiplied by the unit price of the concrete, as billed by the Concrete Supplier and by the quantity of non -specification concrete placed. That value shall be the penalty applied f or the use of the material which did not meet the specification requirements.
601.3.2.4.1 -Optimized Aggregate Gradation: The optimized aggregate gradation is performed by mechanical analysis on all of the coarse and fine aggregates used in any mix desig n. The combined percent retained from all aggregate gradation shall conform Table 601.3.2.4.1A. The combined percent retained from all aggregate gradations in Table 601.3.2.4.1A is based on the Tarantula Curve for optimized aggregate gradation. The contrac tor shall determine optimized aggregate gradation in accordance with MP 601.03.53. Table 601.3.2.4.1A Sieve Size Combined % Retained 1½ in 0% 1 in ≤ 16% ¾ in ≤ 20% ½ in 4 - 20% ⅜ in 4 - 20% No. 4 4 - 20% No. 8 ≤ 12% No. 16 ≤ 12% No. 30 4 - 20% No. 50 4 - 20% No. 100 ≤ 10% No. 200 ≤ 2% Coarse Sand % Retained (No.8 to No. 30 Sieve) > 15% Fine Sand % Retained (No. 30 to No. 200 Sieve) 24% - 34%
The combined aggregate gradation test shall be performed by the contractor (in accordance with MP 601.03.53) at least once for every 50 cubic yards of concrete that are produced from the same mix design. The working range on each sieve from cumulative
321 comb ined percent retained from aggregate gradation shall be in accordance with Table 601.3.2.4.1B. However, not more than one combined aggregate gradation test (for each mix design) shall be required per calendar day as long as not more than 400 cubic yards of concrete are produced in a single day from the same mix design. In situations when more than 400 cubic yards of concrete are produced in a single day from the same mix design, two combined aggregate gradation tests shall be required (one in the AM and one in the PM) for that mix design. Table 601.3.2.4.1B Sieve Size Allowable variation from Combined % Retained in Design Mix Note 1 1 in ± 10% of the % retained on this sieve in the Design Mix ¾ in ± 10% of the % retained on this sieve in the Design Mix ½ in ± 10% of the % retained on this sieve in the Design Mix ⅜ in ± 10% of the % retained on this sieve in the Design Mix No. 4 ± 5% of the % retained on this sieve in the Design Mix No. 8 ± 5% of the % retained on this sieve in the Design Mix No. 16 ± 4% of the % retained on this sieve in the Design Mix No. 30 ± 4% of the % retained on this sieve in the Design Mix No. 50 ± 4% of the % retained on this sieve in the Design Mix No. 100 ± 3% of the % retained on this sieve in the Design Mix No. 200 ± 3% of the % retained on this sieve in the Design Mix
Note 1 The maximum and minimum allowable % retained on each sieve size noted in Table 601.3.2.4.1A shall not be exceeded during production.
During any calendar week (Sunday through Saturday) in which concrete is being produced, a minimum of one combined aggregate gradation test shall be required (for each mix design from which concrete is being produced). This combined aggregate gradation test shall be conducted on the first day of production of that calendar week. Should the moving average of any five consecutive combined aggregate gradation tests have a working range outside of the limits sets forth on Table 601.3.2.4.1B, for any of the sieve sizes listed, production shall be discontinued until appropriate corrections are made. Corrections shall be made either in the aggregate proportions in the concrete mix (the mix design), the gradation of the aggregates, or the storage and loading of the aggregate, as the Contractor may elect. When the small quantity work condition applies, the combined aggregate gradation test required after 50 cubic yards of concrete production shall be performed on the day that the 50 cubic yard quantity is achieved. All concrete produced on that day (the day that the 50 cubic yard quantity is achieved) shall be represented by the previous combined aggregate aggradation test. The combined aggregate gradation test conducted on the day that the 50 cubic yard quantity is achieved shall represent the next 50 cubic yards of concrete produced, beginning with the concrete produced on the next day of production. When, in a concrete mix, gradations tests show that the percentage of material which passes the No. 200 (75 μm) siev e, exceeds the amount permitted in Sections 702.1.2 and 703.4, and provided the Engineer permits the material to remain in place and the Contractor elects to leave the material in place, then a penalty shall be applied in the manner outlined in the followi ng paragraph. It shall be determined which material (coarse aggregate, fine aggregate, or both) caused the total material finer than the No. 200 (75 μm) sieve to exceed the specification limits as
322 determined in Sections 702.1.2 and 703.4. The mass of the material(s) in the concrete mix (Mca, Mfa, or both, as defined in MP 601.03.53), which caused the total material finer than the No. 200 (75 μm) sieve to exceed the specification limits shall be divided by Mt (as defined in MP 601.03.53). The resulting number shall be multiplied by the unit price of the concrete, as billed by the Concrete Supplier and by the quantity of non -specification concrete placed. That value shall be the penalty applied for the use of the material which did not meet the specification requirements.
601.4 -TESTING : 601.4.1 -Sampling and Testing Methods:
Sampling fresh concrete AASHTO R 60 Sampling aggregate MP 700.00.06 Sieve analysis of fine and coarse aggregates AASHTO T 27 and AASHTO T 11 Slump of portland cement concrete AASHTO T 119 Note 1 Air content of freshly mixed concrete AASHTO T 152 AASHTO T 196 Unit weight/Yield of concrete AASHTO T 121 Standard Practice for Making and Curing Concrete Test Specimens in the Field AASHTO R 100 with MP 601.04.20 Compressive strength of cylindrical concrete specimens AASHTO T 22 Total moisture content of aggregate by drying AASHTO T 255 Predicting potential strength of portland cement concrete MP 711.03.31 Determination of Ā of total solids in concrete MP 601.03.51 Determination of free moisture in fine aggregate using 20 gram or 26 gram A “Speedy Moisture Tester” MP 702.00.20 Rapid Chloride Permeability Test AASHTO T 277
Note 1 When testing concrete produced by volumetric batching and continuous mixing, the consistency testing shall be delayed for approximately three to five minutes after mixing.
601.4.2 -Contractor's Quality Control: Quality control of the structural concrete is the responsibility of the Contractor as designated in MP 601.03.50. The Contractor shall maintain equipment and qualified personnel, including at least one certified Portland cement concrete technician who sha ll direct all field inspection, sampling and testing necessary to determine the magnitude of the various properties of concrete governed by the Specifications and shall maintain these properties within the limits of this Specification. The Contractor’s pe rsonnel who conducts the field sampling and testing shall be a certified Portland Cement Concrete Inspector. The quality control plan designated in MP 601.03.50 shall be submitted to the Engineer at the preconstruction conference. Work shall not begin un til the plan is reviewed for conformance with the contract documents. A certified Portland cement concrete (PCC) Technician shall be present at the Concrete Supplier during all batching operations and shall directly oversee those batching operations and any subsequent necessary mix adjustments. A certified PCC technician may perform this work from an alternate remote location, provided that the PCC Technician uses District approved concrete QC batching software to directly oversee all batching operations and
323 perform any subsequent necessary mix adjustments. The details of this remote monitoring shall be outlined in the Quality Control Plan for plant operations. The Contractor shall provide a copy of the quality control test results to the Supplier of t he concrete which was tested within 48 hours of the completion of the test. Any Agency or Laboratory which tests Contractor Quality Control concrete compressive strength specimens, that may be used for acceptance by the Division, shall be evaluated by th e Cement and Concrete Reference Laboratory (CCRL) and certified by the Division as meeting all the requirements of ASTM C1077 pertaining to testing concrete cylinders, as outlined in Section 4.2 of MP 601.03.50.
601.4.3 -Acceptance Testing: Acceptance sampling and testing of Portland cement concrete is the responsibility of the Division, except for furnishing of necessary materials. Quality control sampling and testing performed by the Contractor may be utilized by the Division for acceptance. Stren gth as used in this specification, is only one indicator of the durability of the Portland cement concrete. Evaluation of structural concrete may include evaluation of the freeze -thaw durability, scaling characteristics, abrasion resistance, density and s uch other factors the
601.4.4 -Compressive Strength Tests for Acceptance: A strength test shall consist of three test specimens. Either 6” x 12” cylinders or 4” x 8” cylinders are permitted, provided the requirements of MP 7 11.03.23 are met. The size of the cylinders which the Contractor intends to use on each project shall be listed in the Contractor’s Quality Control Plan. The test shall be the average of the three specimens, except that if one specimen shows manifest evidence of improper sampling, molding, or testing, it shall be discarded and the remaining two strengths averaged. Should more than one specimen representing a given test show definite defects due to improper sampling, molding, or testing, the entire test sh all be discarded. The maximum acceptable range of compressive strengths within a set of three cylinders is 9.5%. This range is found by multiplying 9.5% times the average compressive strength of the three cylinders. If this acceptable range is exceeded, the cylinder that varies the most from the average shall be discarded, and the remaining two cylinders shall be evaluated as outlined in the following paragraph. The maximum acceptable range of compressive strengths within a set of two cylinders is 8.0%. This range is found by multiplying 8.0% times the average compressive strength of the two cylinders. If this acceptable range is exceeded, the entire test shall be discarded. Under no circumstances shall a compressive strength test consist of less than the average of two specimens. Compressive strength tests shall conform to the requirements of Table 601.3.1. Statistical analysis may indicate a percentage of production to be below nominal minimum design strength. Concrete represented by c ompressive strengths below the nominal minimum design strength of Table 601.3.1 may be removed and replaced by the Contractor. If the Contractor elects to leave the material in place, it will be evaluated as to adequacy for the use intended. All concrete evaluated as unsatisfactory for the use intended shall be removed and replaced or otherwise corrected by and at the expense of the Contractor as required in 105.3. When an evaluation indicates that the work may satisfactorily remain in place, a statistical analysis will be made of the material. If this statistical analysis indicates at least 93 percent (93%) of the material may be expected to have compressive strengths equal to or greater than that shown in Table 601.3.1 and 99.87 percent (99.87%) of the material may be expected to have compressive