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State Materials Laboratory
1655 S 2nd Ave
Tumwater, WA

Page maintained by:
Shannon Huber

Construction Materials Services

Materials and Fabrication Inspection

Materials and Fabrication Inspection staff test and approve a variety of materials for use in construction projects.  Often, these materials have protective coatings such as liquid coating, powder coating, thermal spray zinc coating, hot dip galvanized zinc coating, or anodizing. Staff also:

  • Complete visual inspections of materials to assure compliance to contract provisions
  • Ensure that tape measures, digital calipers, survey equipment and other construction-related equipment provide accurate measurements
  • Collect samples of reinforcing bar, paint, bolting material, etc. for testing
  • Witness testing of concrete at the fabricator's facility
  • Review material certifications and documentation as required by contract.

WSDOT Fabrication Inspector, Garrett Webster verifies the location and length of projecting reinforcing bars at the end of a Wide Flange 74 ”girder.”

Send your questions or comments about materials and fabrication inspection to or  refer to the contact list

Chemical testing

At the Chemistry Laboratory, staff conduct a variety of tests on the following roadway construction materials to determine conformance with WSDOT Standard Specifications:

  • Cement (chemical analysis)
  • Joint materials
  • Paints
  • Fencing
  • Pavement markers
  • Epoxies
  • Conduit
  • Bearing pad material
  • Pavement marking materials

Contact Katherine Dafoe, Chemical Laboratory Supervisor, at 360-709-5537

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Electrical testing

Electrical testing staff complete an entire suite of tests on traffic controller assemblies to confirm quality and determine conformance with WSDOT Standard Specifications. Testing methods are listed in the Materials Manual . Staff also complete testing on:

  • Raised lane markers
  • Accelerated weather testing
  • Sign sheeting
  • Electrical conductors

Contact Joe Devol at  360-709-5421

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Physical Testing

Physical testing staff evaluate the quality of roadway and structural materials including:

  • Coarse and fine aggregates
  • Concrete
  • Portland and blended cement , fly ash, and slag
  • Steel
  • Geotextiles
  • Soils and rock

Staff are also responsible for receiving, logging in, and tracking all samples and packages sent to the Headquarters Materials Lab. 

Contact Garrett Webster, Structural Materials Testing Engineer , at 360-709-5446

Tony Briscoe setting the timer for a Sand Equivalent Test

Bituminous Materials Testing

The Bituminous Materials Section staff performs a variety of tests on the following roadway construction materials to determine conformance to WSDOT Standard Specifications:

  • Hot Mix Asphalt (HMA) mix design / anti-strip evaluation
  • Warm Mix Asphalt (WMA) mix design / anti-strip evaluation
  • Mix design conformation testing
  • Performance Graded (PG) binder testing
  • Emulsified asphalt testing

The Bituminous Materials Section also provides forensic testing on asphalt binders and mixtures, new bituminous technology evaluation, moisture-density gauge service and calibration, and special project assistance.

Technician Kristi Young performing WSDOT Test Method T712, Standard Method of Reducing Hot Mix Asphalt (HMA) Paving Mixtures, on a forensic HMA core.

Contact  Steve Davis Bituminous Materials Engineer , at 360-709-5424

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Quality Assurance Program

The Quality Assurance Program requires all quality acceptance testing to be performed by qualified testing personnel using calibrated/verified equipment. The requirements of this program are contained in Section 9-5 of the Construction Manual .

The Materials Laboratory is accredited by American Association of State Highway and Transportation Officials (AASHTO). AASHTO maintains a directory of accredited laboratories . Additional information about accreditation can be found at AASHTO Materials Reference Laboratory (AMRL).

Contact  Randy Mawdsley , Quality Assurance Systems Manager, 360-709-5497 .

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Qualified Laboratory Program

WSDOT does not generally qualify outside private laboratories. Nearly all sampling and testing is performed with state personnel. 

For a region or other subordinate laboratory to be considered qualified, the laboratory shall meet the following conditions summarized below and detailed in  Quality System Laboratory Review (pdf 10.3 mb)  that is part of the WSDOT Materials Manual :

  • Identify all test methods performed on a regular basis. Methods must conform to those established by WSDOT for materials acceptance.
  • Annually, verify laboratory and field test equipment, using State Materials Laboratory equipment verification criteria.
  • Maintain staff qualification for all methods performed in the laboratory. Qualification shall be either by Module Qualified Tester or Individual Method Qualified tester.
  • Respond to the findings of the review program by the State Materials Laboratory staff, modeled on AASHTO Materials Reference Laboratory (AMRL) inspection program. Such reviews shall be conducted at least biennially.
  • With approval of the State Materials Engineer, a non-WSDOT contracting laboratory should have an equipment calibration/verification policy, and a technician training and evaluation process meeting the requirements of AASHTO's Laboratory Assessment Program and compliance with AASHTO Standard Practice R-18 (pdf 198 kb) .

Contact Randy Mawdsley , Quality Assurance Systems Manager, 360-709-5497

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Equipment verification

All Materials Laboratory equipment used for sampling and testing should undergo periodic verification and/or calibration using established calibration verification procedures.

Equipment verification procedures that reflect in-house practices based on the referenced standards are provided below:

Contact Randy Mawdsley , Quality Assurance Systems Manager, 360-709-5497 .

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Tester Qualification Program

The Tester Qualification Program  establishes:

  • uniform testing procedures,
  • insures that testing staff are qualified to perform the testing procedures, and
  • provides a regular review.

The review process, through inspection by the Region Independent Assurance Inspector (IAI):

  • evaluates the performance of all testing staff
  • recognizes proficient performance, and
  • improves substandard performance by recommending corrective action.

Contact David Jones , ASCME - Administration at 360-709-5411 for more information.

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Materials Quality Assurance Engineer

The Materials Quality Assurance Team approve and maintain materials, products, and approved applications for use in highway construction:

 Contact Rob Molohon , Materials Quality Assurance Engineer, 360-709-5441

Construction Quality Audit

The Construction Quality Audit Program is performed by the Construction Division – State Materials Laboratory to document conformance of project records to DBE compliance, construction administration, inspection requirements and materials certification standards.

The goal is to perform a construction quality audit on at least one project per Project Engineer office every two years. Construction quality audits may be conducted more frequently at the discretion of the Construction Division. Projects will be selected with consideration given to project size and complexity.

Upon completion of the audit, the findings are discussed with the Project Engineer. A copy of the final report is sent to the Region Documentation Engineer, Region Construction Engineer, State Construction Office and the FHWA Division Office.

See WSDOT Construction Manual SS 1-09.12 for further details.

Contact: Randy Mawdsley , at 360-709-5446 or Pat Norton at 360-709-5443.


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