As part of Portland Sustainable Building Week, Fortis Construction hosted a Low-Carbon Concrete Roundtable to bring together local industry leaders focused on advancing low-carbon concrete in the Oregon market. The session featured a panel of presenters showcasing the latest research, project successes, and design/construction lessons learned in addressing embodied carbon through cement reduction in concrete.
Brightworks Sustainability (Elena Lake, Sustainable Buildings Technical Lead) shared the “why” behind the urgency of addressing embodied carbon in our buildings, and lessons learned from the consultant perspective in coordinating the process from early owner decision of using low carbon concrete on a project through carbon data collection post-construction.
Oregon State University (Jason Weiss, Professor, School of Civil and Construction Engineering) shared latest research on cutting edge strategies to reduce the Global Warming Potential (GWP) of concrete and software that can be used to predict the performance of concrete when adjusting the material makeup of the mix designs with different supplemental cementitious materials (SCMs).
ZGF Architects (Chris Flint Chatto, Principle Architect) shared a case study of achieving 40% lower carbon concrete on the Seattle Storm’s training complex, quantified via ZGF’s publicly-available Concrete Life Cycle Assessment Tool which project teams can use to compare potential concrete mix designs and calculate carbon savings.
KPFF (Kevin Nadolny, Structural Engineer) shared tips for life cycle assessments between building framing systems and recommendations for writing performance-based specifications to reduce concrete GWP vs. prescriptive-based strength requirements.
Fortis Construction (Charlie Thompson, Project Manager) shared lessons learned from a recent Lane Community College project where all interior and exterior concrete work used a low carbon mix design (20-30% cement content reduction with slag). Lessons learned included creating a budget allowance for potential cost impacts, evaluating risk from installer/ design team, and managing slower cure times on site during concrete pours.
Hearing perspectives from different viewpoints in the AEC industry fostered a great discussion around opportunities and challenges in working towards adopting more low carbon concrete solutions in the industry. The session was heavily attended by local concrete suppliers (CalPortland, Knife River, Whitaker Ellis, Wilsonville Concrete Products) who shared their challenges and risks associated with switching to lower carbon mix designs (longer cure times, schedule impacts, strength test consistency). Representatives from the City of Portland also shared the collaborative approach they are taking working with local concrete suppliers on implementing the City’s Low-Carbon Concrete Initiative on their publicly-owned projects and how they foresee that moving to private projects as well.
One of the biggest takeaways from the session was the importance of prioritizing and discussing low carbon concrete goals as early in the project as possible and engaging with concrete suppliers during design in order to allow for required strength tests of new, low carbon mix designs. Success is dependent on stakeholder collaboration between owners, architects, structural engineers, GCs, concrete subcontractors and suppliers beginning in design and through construction, so regular coordination is key to the success in lowering the carbon footprint of concrete on projects.
Feedback from the Round Table was very positive: multiple attendees mentioned that they had never engaged in such an interdisciplinary conversation on addressing embodied carbon, which is something that has been largely missing from these efforts in the past. The group agreed we need to continue to have these cross-functional conversations to break down the silos in our industry and work towards common goal of progressing these initiatives in the market together. Professor Weiss expressed interest in hosting a similar session with our Willamette Valley market partners in the OSU Graf Research Lab (built by Fortis) where his team is conducting their research on the latest concrete and cement technologies.
Fortis is extremely proud to be on the forefront of innovation in the local construction industry and is committed to these collaborative discussions with our market partners to push the boundaries of sustainability on our projects!