Please pay close attention to the highlighted sections.
All materials proposed for use in concrete and all concrete mix designs shall be approved by the Kansas City Metro Materials Board (KCMMB) prior to use. Such materials include coarse and fine aggregates, cementitious materials, admixtures and water. All materials shall be SAMPLED and TESTED after October 1st of the previous year.
ALL KCMMB approved mix designs for 2019 will expire on April 1, 2020, even if mixes are used on multi-year construction projects. New mix designs must be submitted to GBA to remain an approved KCMMB supplier for 2020. Mix designs, meeting specification requirements, in PDF format, received by February 14, 2020 will be approved by the deadline.
The 2020 submittal process will be similar to last year. KCMMB will preapprove aggregates and cementitious materials. Submit certifications directly to KCMMB. If the material is approved by KCMMB it will be added to the website as an option. An $80 fee per mix design will be assessed if the mix designs are received by February 14th. Mix designs received after February 14th will be assessed a $120 fee. Any mix design requiring approval in less than 10 working days will be assessed a $240 review fee. An additional $120 fee will be assessed for each mix design requiring a second round of comments, $240 for the next round, $360 for the next round, and so on. GBA will invoice for all concrete mix design submittals. Please do not submit payment prior to receiving an invoice. Please make checks payable to GBA. All mix designs must be submitted in *.pdf format. Strength tests will be the first item reviewed in any submittal. Mix designs with incomplete or incorrect strength tests will be returned without further review of the mix design. This will count as the first round of comments.
All mix designs shall be submitted through the website using the Mix Design Submittal Form.
All mix designs are good for one year and must follow the 2020 KCMMB Concrete Material Specification.
If multiple mix designs are anticipated, the KCMMB requires testing only on the range of cementitious materials. For example: A submittal for 15%, 20%, and 25% slag requires C1567 testing for the 15% submittal only, and the testing must meet a maximum expansion of 0.10%.
- Mix Design Submittal Form
- Strength Tests (Including hand calculation of w/c)
Concrete mix design submittals shall include:
- Completed “Mix Design Submittal Form” with attached supporting documentation (strength tests and admixture data sheets).
- Proportion of admixtures (Admixtures for water reduction, set acceleration, set retardation, or viscosity modifiers may be shown as optional Provide addition rate ranges and specific dosage rates for ALL admixtures in the mix design. ALL optional admixtures shall be submitted in the following format for dosage: zero, anticipated dosage, approved range (0, X (Y-Z) cwt. Admixtures listed as optional shall require approval from the owner prior to use.
- Admixtures shall be on the Kansas Department of Transportation PQL. If admixtures will only be used in the State of Missouri, it is permissible to use admixtures as listed on the Missouri Department of Transportation PAL. Admixtures for use in Missouri only will have the following added to the mix design sheet before the admixture name: (MO). The aforementioned requirement is only required for admixtures not appearing on the KDOT PQL.
- Admixture submittals shall include documentation from the manufacturer which provides addition rates. If addition rates for admixtures do not fall within the manufacturers recommended dosage rate, as listed in supplied documentation, a letter from the manufacturer shall be provided. The letter shall specifically state the dosage rate and range approved by KDOT. Individual members reserve the right to reject mixes with admixtures falling outside the manufacturers recommended dosage rates.
- Documentation of Average Compressive Strength:
A minimum of three compressive strength test results are required. A strength test is defined in Article 184.108.40.206 of ACI 318-14. Test strength shall meet or exceed the required average strength as shown below.
Compressive strength test results (strength tests) are required for each mix design submitted. However, if mix designs differ only in water to cement ratio, strength test results for the highest water cement ratio will be acceptable for all mix designs of the series. Strength tests shall be on concrete that contains materials, sources, ratios, admixtures, and admixture dosages consistent with the submitted mix design and shall meet the current specification requirements. For currently approved mix designs, each strength test shall have been completed after the most recent approval date (except as noted below). For new mix designs, strength tests shall have been completed within the previous 12 months.
Each strength test shall represent concrete from separate batches that include all the water, cement, and all non-optional admixtures in the design. The following shall be provided with each strength test:
- Batch tickets or laboratory data including: plant name, design w/c ratio, design weights per cubic yard, total weight of all materials batched, time batched, design slump, moisture correction for aggregates, and dosages of all admixtures. Batch tickets or laboratory data shall be easily correlated with strength test results.
- Documentation for each batch showing how the water/cement ratio was calculated (for example: portland cement, water added at the plant, free water on aggregate, water added on site). Include any other supporting documents. Strength tests, submitted for annual approval, on concrete with water/cement ratios below design are not acceptable. Batch tickets or laboratory data showing unapproved additions to the concrete will not be accepted.
The average of the strength tests shall meet or exceed the required average compressive strength as determined by ACI 301-16, Article 4.2.3, with the following modification:
- At least one half of the tests used to determine standard deviation under Article 220.127.116.11 shall be on strength tests performed after the previous year’s approved mix design date. No test shall be more than two years older than the previous year’s approved mix design date. Documentation showing the standard deviation and all other relevant calculations shall be provided.
Strength test results prior to 28 days are acceptable if they meet all other requirements.
Aggregates and Cementitious Material Submittals shall include (Online Form and Attached PDF Format):
- Contact information
- Source of material
- Aggregate and Cementitious material submittals shall include all pertinent information regarding the specification and will be submitted to the KCMMB administrator. All submittals shall include a statement, from the testing agency, stating the material meets the requirements of the KCMMB specification and, any current, prevailing referenced specifications.
- Test results, performed by a qualified laboratory, that meet the current KCMMB Specification for aggregates.
- Consider sand sources the same, provided they are not more than 25 miles apart on the same river and no tributaries enter the river between the 2 points.
- Test results, performed by a qualified laboratory, that meet the current KCMMB Specification for Cement.
- Test results, performed by a qualified laboratory, that meet the current KCMMB Specification for Secondary Cementitious materials.
- An ASTM C595 certification from the cement supplier, if using a pre-manufactured Type IP (IP) or (IS) cement. The ready mix supplier shall provide an ASTM C150 certification, ASTM C989 certification (slag) or ASTM C618 certification (fly ash), and testing results for ASTM C1567 Mortar Bar Expansion if required. Expansion shall be a maximum of 0.10% at 16 days.
High Early Concrete (Maturity):
In addition to the mix design, a Maturity Curve shall be submitted for any high early strength concrete mixes. The curve will be posted on the KCMMB web site (Private Side). The curve shall be developed in accordance with ASTM C1074: “Standard Practice for Estimating Concrete Strength by the Maturity Method”. The submittal for the Maturity Curve shall include the following:
- Test results from all tests required by ASTM C 1074
- Table of times, cylinder breaks at the times stated, temperature of the concrete at the times stated, and the Time Temperature Factor for the times stated.
- A graph showing the Compressive Strength of the concrete in psi on the vertical axis and the log of the Time Temperature Factor on the horizontal axis, with the data plotted on the graph and a best fit line drawn through the data points.
Mix designs shall be approved for the KCMMB year, April 1st through March 31st.
Please send all submittal information through the website. Contact the KCMMB administrator with questions.
George Butler Associates, Inc.