Quality Assurance (QA) Stewardship Review of the Oregon Department of Transportation

Transcription

1 Review performed: July 25, 2005 thru July 29, 2005 Quality Assurance (QA) Stewardship Review of the Oregon Department of Transportation Report by: Federal Highway Administration (FHWA), Office of Pavement Technology FHWA Review Team: Mike Rafalowski Materials Engineer, Office of Pavement Technology Matt Corrigan Asphalt Pavement Engineer, Office of Pavement Technology Ewa Flom Pavement Programs Engineer, Office of Pavement Technology Greg Schiess Materials Engineer, Florida Division Office Anthony Boesen Area Engineer, Oregon Division Office FHWA Contacts: Dave Cox Division Administrator Oregon DOT contacts: Jeff Gower State Construction & Materials Engineer Sean Parker Construction Training Coordinator Cole Mullis Construction Quality Assurance Engineer Keith Johnston Structure Services Engineer Kraig Kanoff Quality Control Compliance Specialist (QCCS) Mark Wayne Quality Control Compliance Specialist (QCCS) Shane Ottosen Project Manager Cliff Rose Assistant Project Manager Ray Bryant Assistant Project Manager John Scott Project Manager Duane Liner Design Build Manager Dean Chess Quality Control Compliance Specialist (QCCS) Andy Clark Region 3 Quality Assurance Coordinator (QAC) Ted Paselk Project Manager Kevin Peterson Inspector Melvin Dunlap Quality Control Compliance Specialist (QCCS) Scope The purpose and objective of this assessment is to review the Oregon Department of Transportation (ODOT) quality assurance (QA) program, practices, and procedures to ascertain the status of the Agency s implementation of the Title 23 Code of Federal Regulations, Part 637 Subpart B, Quality Assurance Procedures for Construction (23CFR637B) and information sharing on recommended practices. The review looked at the major components of the QA program in the State with an emphasis on the validation and use of contractor quality control (QC) test data used in the Agency s acceptance decision. 1

2 The FHWA Oregon Division Office provided the last written approval of the QA program on October 20, The program has continued to evolve over the past ten years. Material practices involving the regulations were examined at the ODOT Headquarters, District, Regional laboratory, and project levels. A project in Region 3 was reviewed along with asphalt paving project records in the Region 2. Itinerary July 25 Opening meeting in ODOT Headquarters July 26 ODOT Headquarters and Region 2 Salem District Office July 27 Region 2 Corvallis District Office and project review in Lincoln City July 28 Region 3 Roseburg District Office and Regional Lab July 29 Close out with Oregon DOT and FHWA Division Office. Organizational Structure The QA function is located within the Construction Section of ODOT. There are five geographical regions identified for ODOT organizational activities. Each region has a laboratory, with supporting mobile labs used for larger projects. The 5 regional laboratories perform QA testing. The Regional Laboratories report to the Construction Quality Assurance Engineer. In total, quality assurance technicians (QAT) are working in the regional laboratories. A project manager (PM) notifies the regional Quality Assurance Coordinator (QAC) when a QAT will need to take a sample from the project for testing at the regional laboratory. The QAC are brought together for meetings at ODOT headquarters on a periodic basis. A central materials laboratory located in the ODOT headquarters in Salem maintains AASHTO accreditation, provides mix design and construction resources, and performs 3 rd party dispute resolution. Quality Assurance (QA) Program There is one QAC per region with an assistant and multiple technicians. The bulk of ODOT s QA program is contained in the Manual of Field Test Procedures (MFTP) that is designed to be used by contractor and agency technicians for the sampling and testing (including testing frequencies) of construction materials, and to determine their conformance to ODOT specifications. Included in this manual are the Test Procedures, the QA Program, report forms and examples, and the Field Tested Materials Acceptance Guide, to be used by field personnel for guidance, reference and instruction. It was noted that project level personnel readily mention the use of the MFTP. ODOT also has a Nonfield-Tested Materials Acceptance Guide along with a semiannually published Qualified Products List (QPL). The QPL is a comprehensive listing of all finished products found to be acceptable by ODOT for use with specific categories in roadway construction and maintenance. In addition, ODOT maintains a separate listing of disallowed products. There is no formal reevaluation period or requirements for recertifying products listed on the QPL. 2

3 Contractor test results are used in the acceptance of all field tested materials identified in the QA program / MFTP. The State uses the Quality Assurance samples for both verification and independent assurance (IA). Samples are taken by the contractor while witnessed by the Agency s QA personnel. Every QA sample is split with the contractor; 3-way split of IA/QC and backup sample for dispute resolution. The backup portion is taken possession of by the contractor until dispute resolution is agreed upon. The QA split sample is tested at regional labs, while dispute resolution is done by the central lab. The QA sampling frequency is independent of QC frequency. Verification consists of comparing the QA test results to specifications (passing/failure). QA data is to be compared to the QC results to see if they are reasonable according to QA testing history. However there is no formal procedure for this comparison. If a QA tests does not either compare to the QC split sample or pass specification requirements, the QCCS makes an investigation. The material may be retested, the other split may be sent to the Central office for testing. Many times the contractor s results are used without much investigation. Independent Assurance (IA) program The State compares the QA test result to the corresponding QC split test result for IA. The IA tolerances typically use AASHTO precision statement tolerances (some are tighter) which the agency reevaluated last year. The IA tolerances (e.g. maximum specific gravity, asphalt content, maximum density (D f ), bulk specific gravity, and unit weight of concrete) may be too wide open due to reduced variability caused by elimination of multiple test options in the ODOT specified test procedures as well as better process control performed by the Agency s pool of contractors. The Quality Control Compliance Specialist (QCCS) also uses consultants and private lab entities (approx. 30 total statewide). QCCS also serves an IA function to evaluate test procedures and witness technician procedures. It was noted that there is no standard method for documenting, analyzing and comparing IA test results to other test results. It was also noted that there is no standard method for documenting the resolution of discrepancies between IA results and other test results. Technician Qualification Program ODOT works in cooperation with industry on technician certification programs. The certifications have a renewal cycle of 3 years. ODOT also has a procedure for disqualifying technicians (revocation process). ODOT participates in the Western Alliance for Quality Transportation Construction (WAQTC) partnership. ODOT cooperates in an informal tracking system with Western States Alliance (13 States) to track decertified technicians and prevent them from working across state borders. 3

4 The Asphalt Pavement Association of Oregon (APAO) teaches 6 of the available 7 material certifications. The Oregon Concrete & Aggregate Producers Association (OCAPA) and the American Concrete Institute (ACI) provide the concrete certification classes. The industry associations provide the training and then ODOT personnel administer and proctor the certification tests. Laboratory Qualification The ODOT Central Laboratory in Salem is AASHTO accredited. ODOT has five regional laboratories that perform aggregate, soils, and asphalt testing. ODOT uses a lab certification program which certifies all QC and QA testing facilities, and the MFTP includes all testing procedures which comply with AASHTO or equivalent. ODOT requires laboratories to be certified by ODOT Central Laboratory personnel once per year. Contractor calibration services are conducted by a NIST traceable company meeting ISO/IEC requirements. The same criteria are used for ODOT labs. There is up to a one year lab certification suspension if intentional misrepresentation is found. Equipment Calibration ODOT uses an independent calibration service company for all equipment. Lab equipment with annual certification requirements is normally calibrated by an outside entity and is identified by a tag (Example A) showing the latest calibration date. Example A: Equipment calibration tag. Quality Control (QC) Program The Project Manager (PM) has a Quality Control Compliance Specialist (QCCS) reporting to him. ODOT requires the contractor to submit a QC program that is reviewed and accepted at the PM level by the QCCS. The QCCS performs oversight of contractor s field placement activities with the assistance of inspectors. This oversight 4

5 includes 10% verification of contractor s QC. The consultants QC testing must be performed by certified technicians in a certified lab. The QA field units also work with the PM to monitor and provide oversight of the contractor QC. ODOT does not require contractor QC plans to be project or process specific. Most contractors provide the minimum level of QC testing and monitoring that is required by the contract specifications. Hot Mix Asphalt (HMA) ODOT specifies asphalt binder using the PG grading system and specifies Superpave hot mix asphalt mix designs. In addition, ODOT requires the mix design to be evaluated using the Hveem stabilometer. AASHTO T 283 is used for moisture sensitivity. The contactor is required to perform a mix design and submit the data to ODOT. ODOT reviews and accepts the mix design based on a paper review. Mix design raw materials may be requested by ODOT in order to verify the mix design in the laboratory. All mix designs have to be completed by a Certified Mix Design Technician (CMDT). There are approximately 25 CMDTs in the state. Initial binder acceptance is based upon refinery compliance on a bill of lading. During production 2 quart samples are taken from every 1000 tons of HMA produced and submitted to ODOT central lab. Acceptance of additives may be based on product compliance/certification documents and also if it is on the QPL. HMA sampling for volumetrics is taken at drum discharge at the plant (not from the roadway or the truck). Current density acceptance is by nuclear gauge; however ODOT is considering a move toward cores for acceptance. If IA fails rice, the tolerance investigation is done by QCCS and a retest is determined by QCCS. More often then not the backup sample is tested in lieu of a retest. ODOT uses the moving average maximum density (MAMD) of 5 to compare the retest value for the next comparison. After a retest is done the test result not closest to MAMD is discarded. QC volumetric testing is run on a sample from every sublot of 1,000 tons. QA tests are run on a frequency of 10% of the QC testing rate. The contractor averages 5 tests for each sublot for density for QC. The ODOT uses a 12 foot rolling straight edge to determine asphalt pavement smoothness on joints. Profilometer is used for smoothness see ODOT TM 770. ODOT verifies asphalt content by requiring the asphalt plants to have asphalt meters, and production records. The asphalt content that is determined by the ignition test is verified against the meter readings and plant production records. It was noted on one project that the Contractor was allowed to accumulate additional QC samples and/or test results that may have been selected and used for payment or substituted for failing test results. 5

6 Portland Cement Concrete (PCC) The contractor s concrete control technician (CCT) conducts the mix design. ACI 318 and ACI 211 are used for concrete mix design. If the mix does not have historical data a trial batch is required. If there is a strength history for the mix design, ODOT may approve it. The ODOT Concrete Quality Coordinator (CQC) provides mix design approvals. Cement and admixtures are accepted based on conditions under the QPL. The contractor s quality control technician (QCT) measures temperature, slump, air, yield, water-cement ratio. The CCT performs plant inspection and ODOT personnel inspect concrete placement. QC plastic concrete tests are validated as indicated earlier under the Quality Assurance section by ODOT QA results. Structural Concrete Acceptance of concrete is based on plastic concrete tests, and strength. Plastic concrete tests are covered under the general concrete section. QC hardened concrete test results are validated as indicated earlier under the Quality Assurance section by ODOT QA results. There is no percent within limits (PWL) for strength. If the material fails strength and is above 0.85 f c, ODOT performs an analysis to determine if the material can stay in place with a price reduction. If the concrete is below 0.85 f c the material is removed and replaced. Paving concrete Acceptance of concrete is based on plastic concrete tests, strength, smoothness and thickness. Plastic concrete tests are covered under the general concrete section. QC Hardened concrete test results are validated as indicated earlier under the Quality Assurance section by ODOT QA results. There is a PWL for strength. Payment is based on the average of three results using a PWL approach. ODOT uses the California profilograph for acceptance of smoothness. The contract provides a calibrated profilograph and a competent operator. Thickness is measured by sticking performed by the contractor directed and witnessed by the ODOT. Cores can also be ordered. No bonus is paid for thick pavements but a price reduction is determined for thin pavements. Soils Soil density and moisture requirements are determined according to T-99. Field monitoring is conducted using nuclear gauges and proof rolling, which is witnessed by inspector (deflection criteria). 6

7 Aggregates Aggregate quality is source specific. It must meet conditions outlined in the MFTP Section 4A and appropriate project specifications. Testing frequency is outlined by source throughout the state. Unidentified sources use default testing of 1/5000 tons of produced material. All other materials are tested for product compliance on an annual basis. Manufactured Materials ODOT does not have a formal program documented for validating manufactured products. Products basically need to meet criteria and include documentation as identified in the specifications. ODOT approves a number of products on a QPL that is available on the ODOT web site. ODOT may make changes to the list based on: national guidance/requirements or changes to material specs by other entities (ASTM, AASHTO, NCHRP, etc.), failure of a product in service, and exchange information with other states. ODOT uses approval by other states as part of the decision to approve also. National Transportation Product Evaluation Program (NTPEP) data is used when applicable, but ODOT is not a designated test facility for any products. Computer Programs ODOT uses a computer program, Statespec, for comparing contractor QC asphalt test data to specification/ia tolerances. Findings and Recommendations 1. The State is commended for their Technician Qualification Program including their partnership with the Asphalt Pavement Association of Oregon. 2. The State is commended for the control that is placed on the quality of soils through the use of: a. Proof rolling b. One point verification compared to family of curves or single curves. 3. The State is commended for their use of the National Transportation Product Evaluation Program (NTPEP). 4. The State is commended for the quarterly meetings of the Quality Assurance Coordinators (QAC). 5. The State is commended for their use of an informal tracking system with the Western States Alliance to track decertified technicians. 6. The State is commended for their Qualified Products List along with a separate listing of disallowed products. 7. The State is commended for their use of the plant calibration procedures and its incorporation into part of their quality assurance system. 7

8 8. The State is commended for their use of State specified preferred methods that eliminate multiple test options from national standards to reduce variability. 9. The State is commended for investigating, and strongly encouraged to move toward the use of, the following items: a. Air voids in the acceptance and payment of the hot mix asphalt. b. Control on the initial production lot to ensure the compliance of the specifications and the contractor ability to adequately produce, place, sample, and test the mix. c. Use of cores for acceptance and payment by leaving the nuclear gage as a quality control tool. 10. The State is commended for their research program underway to determine the cause of the recent premature asphalt failures. As an example, there is a study underway on the pro-active use of lime antistrip. 11. The State is commended for their use of, and strongly encouraged to continue refining and strengthening, their percent within limits (PWL) acceptance specification. Regulation Compliance 12. Validation of the contractor test results needs to be strengthened. a. The State needs to provide standard guidance for validating the Contractor s test results with the State s verification test results. We recommend using a statistically based method of comparing the States test results to the contractors test results with the F-test & t-test. b. The State needs to increase the use of independent samples that are taken above the number that is indicated in the current procedures (10%) and provide an independent evaluation of the test data. 13. Improve the validation procedures of the contractor s results for smoothness. a. Use of profiler certifications. b. Lock outs on electronics so that data cannot be manipulated. c. Validation by State. Note: for reference, validation is described in CFR (a)(1)(ii)(b), i.e. verification samples need to be independent of contractor s samples. Opportunities for improvement 14. Validation of the contractor test results needs to be strengthened. a. We recommend that the samples are taken from the roadway. i. If not from the roadway, than another suggestion is to sample from the truck at the plant. When a QAT arrives at the plant they can immediately pull the next truck out of line to sample. This discourages a contractor from attempting to make mix modifications at the plant while the QAT is setting up and getting ready to sample from the plant 8

9 discharge. In essence, the QAT is no longer announcing their intent to sample with their arrival at the plant site. b. We recommend providing the QCCSs with electronic data collection and analysis tools to allow them to validate test results and compare test results more effectively (see 19 below). c. We recommend the roles and responsibilities of the QCCS position be revisited to increase the efficiency and productivity of the position. Some of the QCCS responsibilities could be shifted to the QAT or project inspectors. d. Include succession planning for QCCS, etc. 15. Several improvements should be made to the Quality Assurance program. a. We recommend the State develop electronic data collection and analysis tools to more effectively use test result data (see 19 below). b. The State should consider moving the comparison of test results and resolution of discrepancies away from the Project Manager s chain of command. 16. Several improvements should be made to the Independent Assurance (IA) program. a. We recommend developing a standard method for documenting, analyzing and comparing IA data. b. The tolerances that are used for comparing IA test results should be examined; particularly the G mm. 17. Timely resolution of discrepancies in IA, specification, compliance, and validation need to be documented and included in the project files. 18. The State should establish a specified periodic re-evaluation for each product that appears on the Qualified Products List. a. Higher risk products may need to have additional validation and higher test frequencies. 19. The State is encouraged to develop a process to store and statistically analyze test result data electronically and use this analysis to develop and refine the Quality Assurance procedures and tolerances. 20. The State is encouraged to reevaluate the smoothness specification requirements to ensure the present parameters are acceptable b. Reduce the amount of exclusion areas to improve ride in those areas. c. Ride bonus - ensure a bonus is only provided for superior ride quality and not allow the majority of contractors (regardless of quality) to achieve the full ride bonus. d. Balance the material quality and payment with the smoothness quality and payment so contractors won t only put on emphasis on one or the other during production and laydown. 9

10 21. The State is encouraged to have the Central Office assess the QA programs consistent implementation statewide. 22. We recommend the State require the QC technicians to certify each of their test results. As an example, most states require a certification (i.e. statement) for the technician s signature to indicate that the report reflects the actual test results obtained. Concerns 23. The majority of contractors are routinely getting full bonus (1.05) on their asphalt production. 24. The QAT are announcing their sampling of the mix to the contractor by arriving on site, making contact with the plant QC technician and then sampling from the plant discharge. This allows time for a contractor to make changes to the mix production and transition to a different mix by the time it is sampled by the QC technician. 25. The security of the retained (3 rd party) sample possession by the contractor. The possession and storage of retained 3 rd party samples or dispute resolution/backup samples should be taken immediately by the Agency. Manipulation of the samples or replacement by known passing material could occur when the contractor takes possession of the samples. 26. Accumulation of additional QC samples or test results that may be selected and used for payment or substituted for failing test results should not be allowed regardless of if the PM/QAT and contractor agree to this beforehand. 27. Lack of a timely response and resolution of discrepancies and failing test results. 28. The construction staffs apparent lack of confidence of the QA test results. 29. The FHWA Division Office requested a QA program for precast and prestressed concrete items and is waiting for this information. 10