Today, several retailers and speculative developers specify gloss numbers to reduce subjectivity in what constitutes an acceptable finished product, to maintain the aesthetic expectations for retailers moving away from floor coverings and toward exposed polished concrete, to add a little extra “zing” for developers who are competing to lease space, and to reduce lighting expenses for the end user.

Smith's passion is learning and sharing knowledge. He credits his achievements to his employers who were committed to continuing education, his clients who listen and embrace new ideas, and all of the industry experts who have shared and contributed to his knowledge. He participates in ACI, attends World of Concrete to learn and share new ideas with his clients, and reads and attends seminars when he is not conducting seminars for others.

A technology transfer expert

There are few people in the country who know more about designing concrete mixes than Kevin MacDonald, as evidenced by the I-35W Bridge reconstruction in Minneapolis. Mac-Donald's company, Cemstone, Mendota Heights, Minn., received their contract only two weeks before the first ready-mix delivery—little time to develop the several complicated mixes needed—all with specified 100-year service lives or better (see “Bridge to Tomorrow” in December 2008 CONCRETE CONSTRUCTION). Normally several months of testing is needed to research mixes.

MacDonald has been around concrete as long as he can remember. His father taught concrete technology at the university level, and his own education started in high school working for a testing company. After he received his Ph.D. in engineering materials and working for three materials and testing companies, he moved from Canada to the Twin Cities to join Cemstone. He says that he almost took a teaching position a couple of years ago but decided his first love is “technology transfer”—adapting applied research for practical use in the field.

Our country's mass concrete expert

At CTLGroup, Skokie, Ill., John Gajda works with anything that involves temperature and heat transfer, but his specialty is mass concrete. He designs concrete with low heat of hydration and develops cost-effective placement-specific measures to avoid excessive temperatures and thermal cracking issues. Projects include buildings, bridges, refineries, water treatment plants, and government projects—anything with large volumes of concrete. He is so well known for what he does that it's hard to find a mass concrete project in the United States that he hasn't been involved.

Gajda's involvement can be initiated by owners, ready-mix producers, or contractors. His involvement with owners usually focuses on mass concrete specifications and related constructability issues. Contractors and ready-mix producers call him during their bid development, or after they are contracted and required to submit thermal control plans prior to construction. He especially likes working with contractors because he can get deeply involved with detailed construction activities and issues, and has the satisfaction of seeing a project from initiation through completion.

Gajda recently authored a book for the Portland Cement Association (PCA) titled “Mass Concrete for Buildings and Bridges,” and currently is working on a related publication with others for ACI. He is a member of ACI 301 and 207.

The editors of THE CONCRETE PRODUCER magazine announce their own influencers of 2008.