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On this page are pictures of some of the less frequent, but still important testing we perform, and the instruments used to perform those tests. Some photos represent materials that other labs outsource to us for further testing. Sometimes we outsource some of the work from samples we receive to other labs. Basically, all of our labs work together and depend on one another.
Chloride Cores Testing. A Coring crew cores bridges throughout the state, grinds the cores and brings them to us to be analyzed for chloride content. This provides data on how well the bridge deck is holding up. The higher the chloride content, the more road-salt that has been invasive. The more invasive, the greater the demonstrated bridge deck stress. The samples are prepared here in the “wet” lab, and tested for chloride ion percentage by noting the conductivity peak with the same pH meter that we use to test antifreeze. This data is then converted to pounds of salt per cubic yard of concrete and the results are submitted to the coring crew. Once we set up for this testing, we run dozens of samples a day.

Oil Colorimeter. Located in the Bituminous Lab, it is only used on hydraulic oils that are of a questionable quality. An ASTM calibrated colored slide is inserted alongside a slide of the oil sample and the blue light projects an image of the two that will allow a comparison. Any noted color difference provides information as to the potential differences in the additive packages.

On the posts are temporary signage materials and on the panel board are panels of various colors submitted by bidder-producers for evaluation. On the board, the producers are 3M, Stimsonite, and Nippon-Carbide. The panels and signs are placed facing South for maximum sun exposure and left out year-round to see how they hold up to the elements. The panels are evaluated every six to eight months with a retro-reflectometer. The readings are compiled and compared to detect a drop in reflectivity or loss of color quality.

Laboratory Workstation Area. This is where our Lab Reports are created and printed for distribution. The Chemistry Lab was  the first lab to store and backup sample information by PC, and the first to convert all of our reports to databases.

Cotton Duck Sample Bags. The bags are checked to make sure they have the correct stitching and dimensions. The drawstring quality and general workmanship are also scrutinized. Finally, the sample bags are tested for their material type and ounces of weight per square yard.

Aluminum Sign Blank Samples. These samples are an example of inter-lab outsourcing testing. The Physical Tests Lab  cuts these samples from aluminum sign blank sheets which are located at the NDOR Sign Shop on.  An X-Ray Fluorescent Spectrometer determines the alloy percentages of Magnesium, Silicon, Chromium, Manganese, Iron, Copper, and Zinc. Other testing methods can be employed if the results reveal material of questionable integrity.