Dr. Ara A. Jeknavorian is a consultant with Jeknavorian Consulting Services, Chelmsford, Mass. He received a Ph.D. in Analytical Chemistry from the University of Massachusetts-Lowell. He is a Fellow of both the American Concrete Institute and ASTM, and has served as past chairman of the ASTM chemical admixture sub-committee. Before starting his consulting practice, Jeknavorian was a member of the R&D group of the W.R. Grace Co., where he was responsible for developing new chemical admixture technologies and products. He is an inventor on 19 patents and has published more than 40 articles on chemical admixtures. His research interests include admixture technology development, probing cement-admixture interactions, and troubleshooting unexpected cement-admixture performance.