The following contains the minimum requirements for the Producer Quality Control Program in order to become an approved ready mix concrete producer, and to supply certified ready mix concrete to a project.


Producers must submit a written application to the District Materials Engineer (DME) for review and approval. The DME will forward to the Construction and Materials Engineer for signature. The ready mix approval application form is found in Appendix B.


Individual ready mix concrete plants must be calibrated at least once per year. At the time of calibration, the Producer shall provide a written update of contact information, and responsible persons.

NOTE: Producers with operations in more than one District shall apply to the District Materials Engineer where the certified ready mix corporate office exists. The application form is included in this Materials IM.




The following definitions apply to the Quality Control Program guidelines:

Producer the ready mix concrete company and its employees.


Source/Concrete Plant any ready mix concrete plant where certified ready mix concrete is produced.


Conditional Status This is a written notice for the District Materials Engineer to a producer that ready mix concrete will no longer be accepted from a particular source/plant. Application of Conditional Status may vary depending upon situation or specific circumstances. The Conditional Status may apply only to a source/plant. In other situations, when the deficiency is more widespread, the Conditional Status may apply to an entire company or division within a company until the problem is resolved.




1. Ready Mix Concrete Certification


The producer has the overall responsibility of assuring the certified ready mix concrete being batched and delivered to highway and bridge construction projects conforms to all applicable specifications, and the producer Quality Control (QC) Program. The Iowa DOT and Contracting Agency, through their monitoring activities (sampling/testing, visual observations, report checking, etc.), will verify the continued compliance to the program.


2. Knowledge of Current Specifications


The producer Quality Control representative(s) must maintain up-to-date knowledge of the specifications that apply to the ready mix concrete being produced at the source/plant. The producer representative shall have available, at the testing lab, a copy of the current Standard Specifications, all applicable Supplemental Specifications and all applicable Materials Instructional Memorandums for Portland cement concrete production. The producer will be aware of any Special Provisions, or plan notes, which change current Portland cement concrete specifications. This applies to quality, gradation, and operational requirements. The producer shall be responsible for providing these up-to-date publications to their QC representative(s).


3. Certified Plant Inspection


The producer shall perform all required duties of Certified Plant Inspection as defined in the applicable Standard Specifications, Materials IMs, and other contract documents. Certified Plant Inspectors (CPIs) shall possess all necessary Iowa DOT Technical Training Certification Program (TTCP) certifications to perform the necessary sampling, testing and inspection duties as required.


4. Quality Requirements


All materials incorporated in the Portland cement concrete must meet the designated quality before incorporation. The producer is responsible for supplying concrete materials meeting all quality requirements. Intentional shipment of out of specification material will constitute grounds for immediate rejection of material and placement of the source/plant and/or the producer on Conditional Status.


Producer QC staff will perform all required testing and CPI inspections in accordance with all applicable Iowa DOT Specifications, Materials IMs, and other contract documents. Failure to perform all required CPI duties will constitute grounds for placement of either the Producer or individual Ready Mix Plant on Conditional Status and possible suspension of production from the affected ready mix plant(s).


5. Production Notification


Prior to batching operations, the Producer will notify the Engineer (or his/her representative) of anticipated production as soon as practical after schedule is received from the Contractor.


The Producer will be responsible for maintaining continuous, prompt contact with the Engineer (or his/her representative) during all batching and testing operations during the project. The Engineer
(or his/her representative) will be immediately informed of any changes to mix designs or operations.


6. Production and delivery


The producer is responsible for quality control inspection (certified plant inspection) the plant operations at the source/plant on a continual basis. Quality control certified plant inspection can be defined as observing, among other things:

        Concrete plant calibrations and scale checks.

        Stockpiling operations, including deliveries of aggregates and cementitious materials.

        Batching operations, including weighing and mixing operations (including required mixing times, moistures (including probes)).

        Condition of the plant and transport vehicles (including required mixing times/revolutions).

        Project documentation and file management.


7. Documentation


Producer will provide and maintain all required documentation as specified in the contract documents.


BR, HPC, and QM-C Portland cement concrete mix designs will be provided to the Engineer by the Producer prior to batching, as well as flowable mortar designs for critical flow. Standard mix designs will be provided as requested by the Engineer.


Daily/weekly concrete plant reports will be submitted to the Project Engineer and District Materials Engineer by the Producer. The reports will be sent electronically within the required timeframe as defined in the contract documents.

Project diaries will be maintained by the Producer and shall be kept current and made available to the Engineer upon request, for up to three years.


8. Quality Control Structure


In order to ensure quality as a priority, the producer Quality Control personnel will have a line of communication directly to their management, as well as their production operation staff.