News Detail

ACI's Work on Sustainability

3/3/2020

From recent discussions with concrete professionals around the world, I have learned that it may seem like ACI is not engaged on the topic of sustainability. Nothing could be further from the truth. This is my last President's Memo, so I feel it is important to end my formal communications with a discussion of what ACI is doing with respect to sustainability.

One of the largest initiatives that ACI has entered into related to sustainability is through the ACI Foundation's donation of $50,000, specifically by the Concrete Research Council (CRC), to the Concrete Leadership Forum (CLF), an industry-sponsored academic collaboration. This donation, along with donations from various partners in the concrete industry, is being used to develop an Embodied Carbon in Construction Calculator, named EC3, to provide transparent and realistic measures of embodied carbon in concrete construction. EC3 is now in a beta phase and is being tested by concrete design professionals in the industry.

This past December, ACI presented a webinar on the topic of embodied carbon in concrete construction, hosted by Past President Anne Ellis with a technical presentation by Kate Simonen, founding Director of the Carbon Leadership Forum and Professor in the College of Built Environments at the University of Washington. The webinar highlighted and developed pathways for "carbon-smart" building materials to be part of the global climate solution, and it included an introduction of the EC3 tool as a viable means for owners, designers, and contractors to reduce GHG emissions in their building projects. The webinar was recorded and is available as an on-demand course on ACI's website.

ACI Committee 130, Sustainability of Concrete, has recently issued a report—ACI 130R-19, Report on the Role of Materials in Sustainable Concrete Construction—that provides an excellent, fair, and balanced discussion about cement manufacturing and the production of greenhouse gases relative to other industrial sectors in the United States. The fact is that cement is at the lower end of the spectrum when compared to the oil, gas, and chemical industries, and it is in the middle of energy consumption and greenhouse gas emissions compared to the other major construction materials. Moreover, it should be noted that the amount of energy used in production of cement today is approximately 40% lower than the amount used 40 years ago.

It is worth noting that ACI 318-14, Structural Concrete Building Code, in Section 4.9, provided for the first time that sustainability requirements can be used in design, in addition to the strength, serviceability, and durability requirements of the Code. In ACI 318-19, additional sustainability provisions were introduced. Provisions for the use of alternative cements and recycled aggregates, within limits, are now outlined for concrete production.

For the current ACI 318 Code cycle, Chair Andy Taylor has formed a new subcommittee (ACI Subcommittee 318-N, Sustainability) to work on greatly expanding the concrete building code provisions related to sustainability design. This subcommittee is being chaired by Shana Kelley. The plan is for the subcommittee to develop an appendix for the Code that will provide for materials, methods, and procedures to design concrete structures for sustainability.

The approach for sustainability design will be based on the "cradle-to-grave" concept, which not only looks at the embodied carbon and operational carbon for a building but also includes life-cycle cost or other rational analyses to quantitively demonstrate the effects of design options. Traditional sustainability design only includes the embodied carbon—the CO₂ generated up to the start of the life of a building, referred to as the "gate" or "starting gate." The analysis of service life, durability, and resiliency has to be considered for a realistic view of the sustainability of a concrete building.

It is hard to believe that my presidency is ending at the beginning of April. I hope this last memo communicates to Institute members and partners that greenhouse gas (GHG) emissions and global warming are huge topics for ACI as well as the world at large. Significant work is in fact going on within the Institute with respect to sustainability. Sustainability is here to stay, and all of us in the concrete industry must embrace the concept and do our part to ensure that concrete structures built today provide sustainability for generations of users.

Randall W. Poston
ACI President