Dr. Jason Weiss, School Head and Professor in the Department of Civil & Construction Engineering as well as Director of the Kiewit Center for Infrastructure and Transportation Research at Oregon State University, presents a seminar at NJACI Dinner Meeting on “A Roadmap for Test Methods, Models and Specifications for Concrete Durability Performance” at the NJACI Dinner Meeting held on Tuesday 1/15/2019.
TOPIC: A Roadmap for Test Methods, Models and Specifications for Concrete Durability Performance
There is greater need to integrate durability-based design processes in the design of concrete infrastructure. The majority of pavements and structures are failing due to durability. The mixture proportioning of modern concrete is changing from traditional four-component simple systems to complex engineered mixtures to meet various requirements, including fresh and hardened properties. A four-step approach procedure that can be used to develop for performance specification for concrete durability was presented and involves:
a) development of simple and repeatable test methods that can be used to assess performance;
b) conversion of test values to fundamental properties of concrete using various models;
c) relating properties with exposure conditions that are different across the country; and
d) establishing performance grade and use test methods for Q/C to ensure that design properties are obtained.
The presentation will stress the importance of fundamental understanding of factors affecting concrete deterioration (for example capillary porosity and surface tension of pore solution) and the development of mitigate strategies (e.g., use of shrinkage reducing admixtures (SRAs) and/or saturated lightweight sand for internal curing (IC) to mitigate shrinkage) instead of simply reducing paste volume.
The four-step approach to durability design will be demonstrated through:
a) determination of electrical resistivity and Formation factor to estimate time to corrosion of reinforcing steel given geometry of concrete element, RH, temperature, concrete cover, etc.);
b) integration of shrinkage and cracking measurements and use of probability-based shrinkage specifications to estimate risk of cracking; and
c) understanding the fundamentals behind concrete deterioration associated with new de-icing salts leading to the formation of Calcium Oxychlorides (CaOxy) and new concepts involving freeze/thaw saturation model to reach critical saturation and frost damage, even in air-entrained concrete.
BIOGRAPHY
Jason Weiss is the Edwards Distinguished Chair in Engineering and the Director of the Kiewit Center for Infrastructure and Transportation Research. Before joining Oregon State as the Head of the School of Civil and Construction Engineering he was a faculty member at Purdue University for over 16 years where he held the position of the Jack and Kay Hockema Professor of Civil Engineering and Director of the Pankow Materials Laboratory. He earned a B.A.E. from the Pennsylvania State University and a MS and PhD from Northwestern University in 1997 and 1999 respectively. He is actively involved in research on cement and concrete materials specifically focused on early age property development, cracking, transport in concrete, and concrete durability. Specifically, he is known for research his group has performed in the areas of shrinkage and cracking reduction, the use of the ring and dual ring test, use of electrical resistivity and the formation factor, use of internally cured concrete, and concrete pavement durability.
Dr. Weiss has taught courses in civil engineering materials, concrete materials, service life, repair and non-destructive testing. His primary research interests are in the area of early age shrinkage cracking and mitigation as well as service life sensing and prediction.
He is also a primary author of the durability tests for the Performance Engineered Mixtures/Performance Related Specifications programs underway at FHWA. He is currently the Editor-in-Chief of the American Concrete Institute’s Journal of Materials and is the former editor in chief of the ASTM journal of Advances in Civil Engineering Materials and the RILEM journal Materials and Structures.
Dr. Weiss has authored over 400 publications with over 200 peer-reviewed journal articles. He is recipient of the NSF Career Award, the RILEM L'Hermite Medal, the ACI W. P. Moore, ACI Young Member, ACI Philleo, and ACI Wason Awards, the ESCSI Erskine Award, the TRB Burgraff, AFN040 section award, and Mather Awards for outstanding research and publications, the ACPA Knutson award, and the ASCE Huber Award. He is a fellow of ACI and is also the recipient of the Wansik, Munson, Buck, and Burke award for outstanding teaching/advising in the School of Engineering, the Potter award for outstanding teaching in the College of Engineering, the University Murphy Award for undergraduate teaching, and has been inducted into the Purdue Teaching Academy.