October 4, 2013

« All News

Brandon Klenzendorf Co-Authors Journal of Hydraulic Engineering Article on Methodology for Measuring Hydraulic Conductivity of Porous Pavement Friction Course

AUSTIN, Texas — Geosyntec staff member Brandon Klenzendorf, PhD, CPESC, co-authored the article "Methodology for Determining Laboratory and In Situ Hydraulic Conductivity of Asphalt Permeable Friction Course," which was published in the January 2011 issue of the ASCE Journal of Hydraulic Engineering. Brandon's co-authors were Randall Charbeneau, Professor of Civil Engineering, and Michael Barrett, Research Associate Professor, from the Center for Research in Water Resources at The University of Texas at Austin.

Permeable Friction Course (PFC) is a layer of porous asphalt overlain on conventional roadway surfaces and used for its safety and water quality benefits. In order to determine whether the benefits of PFC are expected to persist in the future, the authors developed new test methodology for determining the hydraulic conductivity of PFC. A constant head test was conducted on core specimens in the laboratory, and a falling head test was conducted in the field. During testing, the flow conditions through PFC result in two-dimensional cylindrical flow experiencing a nonlinear flow relationship. Additional modeling techniques are required to determine the hydraulic conductivity from the nonlinear flow pattern. The authors present both porosity (approximately 20%) and hydraulic conductivity (on the order of 1 cm/s) data for three roadways near Austin, Texas over the past two years. A nondestructive test procedure for determining the in-situ hydraulic conductivity is described and is useful for assessing the extent to which the benefits of the PFC layer will persist. Measurement of the hydraulic conductivity of PFC is also useful for design purposes.

Brandon earned his PhD in civil engineering with an emphasis in water resources and hydraulic engineering. In addition, he received his Master's degree in environmental and water resources engineering and Bachelor's in civil engineering honors. Brandon received all his degrees from the University of Texas at Austin. This article was part of his research work while pursuing his doctoral degree under the supervision of Dr. Charbeneau and Dr. Barrett.