Othman AlShareedah from CMCL presented his work on developing a mechanistic thickness design method for pervious concrete pavement (PCP) at the American Concrete Institute (ACI) 2019 Fall Convention in Cincinnati, Ohio. The mechanistic method involved investigating the in-situ elastic modulus and modulus of subgrade reaction of 14 PCPs across Washington State and developing a flexural fatigue model for pervious concrete pavement. The fatigue model was developed using a total of 66 PC beams made with two aggregate types (angular and round) and three porosity levels (20%, 25%, and 30%) under flexural fatigue loading in three stress ratios (SR): 0.75, 0.8, and 0.85. Recommended PCP thicknesses were proposed using the developed fatigue model, the in-situ mechanical properties of PCP, and traffic categories based on the American Concrete Institute (ACI) guide for the design of concrete parking. The developed thickness design method and the database will bridge the current knowledge gap in the structural design of pervious concrete pavement. The results are published in two papers in ASCE and C&BM journals.

CMCL was recently awarded a project by the ARPA-E program of the Department of Energy to work on using bio-based nanofibers in concrete. The focus will be on the rheology and mechanical performance of cementitious systems. In this exciting project, we work with material scientists at WSU and the Pacific NW National Laboratories to design a green effective new additive for concrete.

Our article titled, “Advanced calibration of historic apparent moisture diffusivity models for mortar” led by CMCL former student, Dr. Milena Rangelov was recently accepted for publication in ACI’s Materials J. Keep a watch out for this publication in the upcoming issue of the ACI journal. This paper provides insight into apparent diffusivity models commonly used by researchers and used in building codes by simplifying their so many parameters and providing guidance to choose suitable values.