The Chapter's October 8th dinner and program was held at the Hilton Garden Inn Sacramento Airport Natomas in Sacramento, from 6:00 to 9:00 p.m.

In response to Senate Bill 596, the concrete industry is working to reduce CO2 emissions while developing sustainable solutions that result in strong, durable, economical, and practical concrete. Dr. Jose Garcia has been a key figure in advancing research on sustainable concrete. He began his work at the University of Texas, Austin, and later brought his expertise and passion to California State University, Sacramento (Sac State), where he has inspired students like Arturo Perez-Hunt to pursue similar research.

Dr. Garcia’s current research at Sac State focuses on concrete sustainability, alternative cementitious binders, and long-term field exposure of concrete specimens. With access to multiple labs and equipment, Dr. Garcia is equipped to conduct a variety of experiments and has established outdoor exposure sites on campus to test sustainable concrete. Over the years, he has collaborated with students to explore the use of recycled plastic as an alternative aggregate. He has also laid the groundwork for durability testing of low-clinker mixes made with Type IL cement and supplementary cementitious materials (SCMs) in partnership with Arturo Perez-Hunt. Currently, Dr. Garcia is investigating the use of water treatment sludge as an alternative SCM and plans to evaluate the durability and field performance of low-clinker mixes with Type IL cement and SCMs, especially mixes containing calcined clay.

Arturo Perez-Hunt has conducted comprehensive mechanical and bulk electrical resitivity testing on low-clinker mixes, with cement clinker levels ranging from 34% to 44%, using Type IL cement and SCMs. His testing involved two curing regimes: one set of cylinders was cured in a standard curing room at a temperature of 23°C, while another set was cured for 24 hours in a limewater bath at 50°C before being moved to a standard curing room. Fourteen different mixes were evaluated, with a constant water-to-cement ratio of 0.42 and 645 pounds of cementitious material per cubic yard for all mixtures. All mixes incorporated Type IL cement along with various amounts of Grade 120 Slag, Metakaolin, Class F Fly Ash, and Class N Natural Pozzolan. Compressive strength testing and bulk electrical resistivity measurements were taken at intervals of 3, 7, 14, 28, 90, 180, and 365 days. With assistance from Sac State students, approximately 700 4x8 cylinders were cast and tested.

Arturo’s findings revealed that elevated temperature curing increased early compressive strength in all mixes with this effect diminishing at and after 28 days. By 90 days, the low-clinker mixes continued to gain strength, with most performing comparably to the control mix of only Type IL cement. He also noted that mixes containing SCMs exhibited high electrical resistivity, which correlates to high resistance to ion penetration, and continued to improve beyond 28 days. On the other hand, the control mix of Type IL cement and no SCMs showed only moderate resistance with little improvement beyond 28 days. Arturo concluded that increasing the proportion of SCMs in the mix positively correlated with enhanced durability.

The Chapter would like to thank Jose Garcia and Arturo Perez-Hunt for this interesting and informative presentation.