Greenbuild Session – Blended Cements: Successful Implementation for Lower-Carbon Concrete

November 5, 2025 Los Angeles, CA

ACA Events

Overview

Join us for this session at Greenbuild 2025, where we discuss successful strategies for the implementation of lower-carbon concrete. Concrete is a carbon-efficient and resilient building material that will remain a vital component of our built environment as we face increasing threats from natural disasters in the years to come. Concrete structures are often the only structures left standing following destructive weather events. The cement and concrete industries intend to achieve carbon neutrality by 2050. An important strategy to achieve this goal is the widespread adoption and use of blended cements and supplementary cementitious materials. Blended cements offer an up-front reduction in embodied carbon as a starting point for all concrete mixtures while retaining the opportunity for further carbon reduction using existing and new strategies.

Knowledge, communication and collaboration across the project team of suppliers, producers, contractors, owners and trade subcontractors will ensure success in both performance and carbon goals. In this panel session, attendees will learn the technical basics of blended cements from a material producer, specification guidance from a structural engineer, and lessons learned in practice from a concrete contractor.

The session will educate on currently available options to reduce carbon on concrete projects and deliver insights from an expert panel through shared best practices, technical information, and case studies. The interactive session will provide attendees with an opportunity for Q&A.

Learning Objectives

Understand the 5 links of the cement industry’s Roadmap to Carbon Neutrality.
Describe the fundamental differences between a blended cement and portland cement.
Discover what innovative materials are likely to become mainstream for use on upcoming projects.
Identify opportunities for carbon reduction in a concrete specification.

Speakers

Dirk Kestner, PE, SE, LEED AP BD+C, is a Senior Principal and Director of Sustainable Design for Walter P Moore, a 1,000+person structural and enclosure engineering firm. Dirk is a licensed Professional and Structural Engineer and is a LEED APBD+C. Dirk is a current board member of The Carbon Leadership Forum. He was the founding chairman of the Sustainability Committee for The Structural Engineering Institute and served as an editor and coordinator of the committee’s book Sustainability Guidelines for the Structural Engineer. He previously chaired the LEED MR-TAG and served as a subject matter expert during the revisions to the WBLCA credit for LEED v4.1. He frequently speaks on the application of lower embodied carbon concrete mix designs and the use of WBLCA to optimize design. He holds degrees from Cornell University and The University of Texas at Austin where his graduate research studied the use of recycled aggregates in concrete mixes.
Joel Ahearne-Ray, LEED AP BD+C, Assoc. DBIA, is the Senior Materials Specialist with the Turner Engineering Group for Turner Construction, where he supports project teams nationwide across disciplines including concrete, steel, MEP systems, and interior finishes. His work focuses on material performance, environmental impacts, and advancing healthier, lower-carbon solutions for the built environment. Joel has guided project teams in adopting innovative materials and practices, translating research and supplier developments into practical field applications. He also chairs Turner’s Low Carbon Materials Committee and is deeply engaged in research on sustainable and healthy building materials.
Shane Mulligan, P.Eng., LEED Green Associate, is the Sustainability Market Manager for Heidelberg Materials, where he is responsible for all aspects of sustainable sales and marketing efforts in North America. This includes working with architects, engineers, and designers towards lower carbon, sustainable solutions in the built environment. He has over 20 years of experience in a variety of civil engineering sectors including the technical promotion of cement and concrete products, structural design of underground infrastructure, waste diversion planning, and stormwater management. His experience includes previous roles with the Cement Association of Canada and Lafarge.
Aubrey Garinther (Smading), M.S., P.E., LEED Green Associate, is the Director of Concrete Design and Technology at the American Cement Association and works to advance ACA’s Roadmap to Carbon Neutrality. Aubrey leverages her experience as a structural design and forensics engineer, as well as her experience maturing novel concrete technologies, to support decarbonization of the concrete and construction links of the industry’s value chain. Prior to ACA, Aubrey supported the development of codes and standards for the concrete 3D printing industry. Past experiences include forensic structural evaluation, structural design for interstate highway projects, and construction administration for multi-family development projects.

Aubrey is a licensed Professional Engineer in Texas, Louisiana, Alabama, and Florida. She earned her Bachelor and Master of Science in Civil Engineering from Southern Methodist University. Aubrey actively serves on committees within the American Concrete Institute (ACI), the Structural Engineering Institute (SEI), and the Structural Engineers Association of Colorado (SEAC).

Registration Information

This event will be held at The Greenbuild International Conference and Expo. Click here for more information and registration details.