Editor’s Note: This is a two-part article that provides an overview on performance engineered mixtures, and where things stand on a 5-year plan to advance this important quality initiative.  Based on a meeting in Minneapolis this week, the first part of this article provide an overview of the PEM vision.  Look for the second installment in a special issue of ACPA TODAY on Tuesday, November 26.

A performance engineered mixtures (PEM) technical advisory committee or TAC meeting this week gave stakeholders an opportunity to share updates and information on activities related to this broad quality initiative. 

Jerry Voigt represented ACPA at the meeting, whose participants also included FHWA and state transportation officials, the CP Tech Center, PCA, NRMCA and several ACPA-affiliated chapters.

The PEM vision is to develop a better way of accepting concrete for paving. This includes choosing parameters that matter more to durability, finding tools to measure them (including some new tests), choosing appropriate test limits and developing protocols for applying the tests properly in terms of purpose, consistency and repeatability. PEM is trying to improve the delivery of concrete pavements that lower the risk of premature material failures, while allowing for contractor innovation, adaptability for local conditions and an appropriate level of inspection/testing. 

Although the PEM program is focusing on mixtures, it also includes consideration of state quality programs and contractor construction practices.  At nearly halfway into the 5-year program, some important guidelines have been prepared, and a provisional standard— AASHTO PP84—has also been developed.   (To be continued in ACPA TODAY, Tues., Nov. 26.)

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Photo:  Choosing appropriate test limits and developing protocols for applying tests is an essential part of the PEM initiative.  (Photo by ACPA staff.)