As the Performance Engineered Mixtures (PEMs) program gains momentum, the concrete construction community—including owners and contractors—are starting to ask about how to implement PEM in their daily work, and what impacts the program is going to have on them. This tech brief seeks to address those questions. But, what steps can concrete industry professionals take to add PEMs to their arsenal of quality assurance tools?
For all those interested in more information about PEM, a recently published 7-page tech brief titled “Performance Engineered Mixtures for Contractors”, written by Peter Taylor, Director-National Concrete Pavement Technology Center (CPTech Center), provides guidance on properties, processes, and recommended tests for the laboratory and the field. This publication was sponsored by the FHWA, the National Pooled Fund Study (TPF)-5(368), and the concrete industry.
The PEM program is based on the premise that if the right concrete is designed (or specified), developed, delivered, and placed for a pavement, the risk of rejection by the agency is reduced in the short term, and that maintenance is significantly reduced in the long term. This will
lead to savings to contractors, agencies, and pavement users, as well as improvements in safety, because traffic cones need to be placed less often.
The tech brief provides guidance on properties, processes, and recommended tests for the laboratory and the field. For those who want to rely more heavily on pre-qualification tests, it also includes detailed information on which tests are available to gauge workability, air void system, unit weight (density), strength development, and transport qualities. The brief also lists recommended tests for quality control and acceptance by the agency involved.
For the entire PDF of the 7-page Tech Brief, please go to: https://intrans.iastate.edu/app/uploads/2018/11/PEM_for_contractors_tb.pdf
For the National CP Tech Center link to the PDF, please go to: http://www.cptechcenter.org/news/new-pem-tech-brief-available/
Home page photo: Cover of Tech Brief
Photo 1: Angela James Folkestad, Executive Director-CO/WY Chapter-ACPA:
Demonstration day in Colorado-FHWA Mobile Concrete Laboratory (MCL)
illustrated new tests for the PEM program.
Photo 2: Jagan Gudimettla, FHWA MCL 2015: Box test result for a stiff mixture.
Photo 3: CPTech Center: Use of the VKelly test (left) to assess response
to vibration for mixture workability and super air meter (right)
for indication of air distribution in concrete for freeze-thaw durability