October 11th found thirty Chapter members and guests back at Cattlemens in Livermore. The Social Hour, complete with tempting appetizers, provided ample opportunity for networking and hashing the state of the industry.
Cattlemens' prime rib was once again the entree of choice for most attendees, and waitress Hayla was quick, efficient, and friendly. (She's actually a bartender. No wonder she was so good at multi-tasking!)
Immediate Past President and Programs Chair Jaymi Fridley welcomed those in attendance, thanked the student sponsors, and provided a quick recap of upcoming events. She then introduced the evening's guest speaker, Randy Romeo, Cement Technical Services with CalPortland Company.
Randy presented a thorough and timely update on the use of Portland Limestone Cement (ASTM C595, aka Type 1L) in our geographic area. It's a type of blended cement that contains between 5 and 15% limestone. The product itself performs much the same as standard (ASTM C150) cement but it comes with great benefits.
What makes it so popular is that the limestone content results in a significant reduction of CO2. Type 1L has a lower global warming potential (GWP) due to the reduction in clinker use. This increased focus on sustainability is one of the reasons why it has grown in popularity across the US. The use of Type 1L has been approved by the California Department of Transportation (Caltrans) as an eco-friendly alternative to traditional cement, and is expected to see a marked increase in use for commercial buildings in the near future.
Randy noted that, during the manufacturing process, the Blaine fineness of Type 1L must be increased by approximately 10 points per 1% of limestone.
One of the challenges for the product is obtaining a passing result for sulfate resistance (ASTM 1012). An ASTM committee is reviewing the applicability of the Standard to Type 1L, and many in the industry feel ASTM C452 is the better standard for evaluating sulfate resistance.
Another hurdle to be overcome by the industry is convincing the specifiers to modify project specifications to allow ASTM C150 OR C595 cements. It was noted that for every ASTM C150/AASHTO M85 cement, there is a C595/M240 replacement. Availability and acceptance are the primary challenges.
The Chapter extends its thanks to long-time Organizational member Randy Romeo, and CalPortland, for this informative and dynamic presentation.