AASHTO NTPEP DataMine for Structural Steel Coatings – Its Value and Use


The American Association of State Highway and Transportation Officials (AASHTO) is a nonprofit, nonpartisan association representing highway and transportation departments in the 50 states, the District of Columbia, and Puerto Rico. It represents all five transportation modes: air, highways, public transportation, rail, and water. Its primary goal is to foster the development, operation, and maintenance of an integrated national transportation system.

AASHTO works to educate the public and key decision makers about the critical role that transportation plays in securing a good quality of life and sound economy for our nation. AASHTO serves as a liaison between state departments of transportation and the Federal government. AASHTO is an international leader in setting technical standards for all phases of highway system development. Standards are issued for design, construction of highways and bridges, materials, and many other technical areas.

Background – NTPEP

The National Transportation Product Evaluation Program (NTPEP) is a technical service program administered by AASHTO. NTPEP cooperatively tests manufactured transportation products that are of common interest to all member departments and shares the results from the laboratory and field evaluations of these products. Product listings are provided in three categories: traffic safety, construction and maintenance.


The test data generated on various highway products (according to the NTPEP Work Plans) by State laboratories or independent testing laboratories is made available through a portal known as the AASHTO NTPEP DataMine, an online repository of data for all NTPEP services. The database provides the tools for performing queries that assist in analyzing and reporting on products tested through NTPEP.

AASHTO NTPEP DataMine – Structural Steel Coatings

aashto ntpepOne of the “products” included in NTPEP is Structural Steel Coatings (SSC). It is listed under the Maintenance category. It provides data on the performance of coating systems (by manufacturer and brand names) subjected to long term (5000-hours) salt fog exposure (ASTM B117), cyclic weathering (ASTM D5894) for 15 – 336-hour cycles, including color difference and gloss retention data, adhesion (ASTM D4541), post thermal cycling adhesion data (ASTM D6944/D4541), and provides slip coefficient properties of the primer when it is intended for use on the faying surfaces of slip critical bolted connections. Compositional analysis of the individual coating components and the mixed product is also populated to DataMine. No “pass/fail” is assigned to any of the tests and acceptance criteria are not provided, only data.

When we think of “mining” we think of extracting a product that has immediate value (diamond mines) or potential value once it is processed (various minerals used in manufacturing). In this case the product being “mined” is performance data of coating systems applied to structural steel that is independently generated. It holds value for both a facility owner and the coating manufacturer:

  • Coating manufacturers pay one time for independent testing and potentially gain access to multiple Approved Product Listings (APLs);
  • The testing protocol is standardized, so system comparisons are consistent with one another;
  • No written reports are generated, so there is no need for dissemination of reports to individual Owners, or multiple individuals working for a single Owner;
  • Datamine provides real-time access to data as it is generated and released by the coating manufacturer (including digital images of the test panels);
  • Once data is released, it can be immediately evaluated by Owners for APL consideration; and
  • Owners are provided access to new technology as well as “tried and true” systems.

User Application of DataMine

An example of how Datamine is used is The Northeast Protective Coatings Committee (NEPCOAT), an affiliation of nine northeast states that has developed acceptance criteria for the protective coating systems submitted and tested through AASHTO NTPEP. The committee mines the data released by the coating manufacturer semi-annually, and applies its pass/fail criteria to the test data to create a single APL for use by all nine member states. Other agencies have access to the APL via the internet (http://www.nepcoat.org).

DataMine can be accessed on the internet (http://data.ntpep.org/); data can then be “mined” by clicking on the Structural Steel Coatings link and searching by manufacturer.

Note that while a host of compositional analysis on each product (and in many cases each component of each product) in the coating system is posted to DataMine, this data is not visible to the public since it is considered proprietary. Only AASHTO, it’s member agencies, the testing laboratory and the manufacturer who submitted the products can access this data.

bill corbett ktabill corbett kta