MTO Reference Materials for Control, Calibration and Development of Soil and Aggregate Test Methods

Abstract
The Ministry of Transportation of Ontario (MTO) has been actively involved in developing and establishing reference materials for soil and aggregate test method development, as well as test method control and calibration for over 35 years. The primary function of these materials is test method control and calibration for the critical purpose of ensuring the highest quality testing in support of durable Ontario infrastructure. Many of MTO’s reference materials have been cited and used in test methods and publications by ASTM, CSA, RILEM, and numerous other internationally recognized research publications over the years.

Many applied, practical and experimental research projects that are engaged in test method development and innovative technologies development are requestors of MTO’s reference materials. These projects are normally in need of control materials with established or “known” parameters and/or established field performance to use in support of their research programs. MTO has historically both directly and indirectly greatly benefitted from this external research as a result of the practice of providing control materials.

This paper provides an overview of MTO’s reference material program including its development and evolution. MTO’s new reference material code system is presented, as well as the procedure for requesting materials and MTO’s policies for making materials available to requestors.
A summary of the different reference materials currently available and their intended usage, such as which materials are used for control and calibration for which test methods, will be provided. There will be mention of the historical reference materials, that although may be commonly recognized, are now out of stock and no longer available, e.g., the “Brechin Aggregate”. The newer materials that have superseded and replaced these historic ones are detailed, e.g., “Drain Brothers Stoney Lake”. Currently there are ten to twelve different reference materials that are either actively in use and/or are in the process of being established for future use. Commonly known names for some of these materials include Spratt #3, Pittsburg, Sudbury Gravel, Dresden Clay, etc.

Reference material summaries include each material’s physical and engineering property test ranges as well as descriptions of each material’s field performance and geological environment of origin, where available. The chemistry and petrography for each is also included where available.

The reference material program demonstrates MTO’s leadership and ongoing commitment to promoting quality testing of soils and aggregates for more durable infrastructure. MTO’s reference materials have historically been used for and will continue to provide a solid foundation for test method development and research into the development of new and innovative technologies in the soils and aggregates field.