2. Staff briefing on the City of Austin Action Plan to Transition to Low-Embodied Carbon Concrete — original pdf

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City of Austin Plan to Transition to Low – Embodied Carbon Concrete In Pursuit of a Carbon Neutral Austin Transportation and Public Works Amica Bose, P.E., Assistant Director, Office of the City Engineer March 25, 2026 City of Austin Path to Sustainability: Low Carbon Concrete Why This Initiative Matters ▪ Traditional cement and concrete have a significant impact on the sustainability of our built environment and infrastructure. ▪ Austin has a near-term opportunity to reduce emissions; have direct impact on infrastructure and capital projects ▪ Scalable across city operations and private development ▪ A resolution from the Austin City Council enables the City to begin advancing lower- carbon concrete practices. ▪ Low Carbon Concrete is one of the multiple focus areas within the Climate Resilience Framework 2 City Council Resolution Resolution 20230420-024 passed on April 20, 2023 City of Austin Low-Embodied Carbon Concrete Initiative ▪ Develop a plan to progress toward Low-Embodied Carbon Concrete 1) Provide Concrete Tracking that a) Identifies how much concrete is used and its impact b) Require the use of EPDs to influence and encourage more sustainable concrete production c) Strategy to review, pilot, and approve alternative, more sustainable concrete mix designs 2) Establish specifications and designs that allow for meeting the need for lower-embodied carbon concrete. 3) Provide annual report to City Council on progress toward the overall goal of more sustainable concrete. 3 Roadmap for Implementing Low-Carbon Concrete Measure • Measure Carbon Footprint – Establish a protocol to calculate and track the City of Austin carbon footprint annually. (Task 1a) Increase • Increase Material Transparency – Implement Environmental Product Declarations (EPDs). (Task 1b) Enable • Enable Low-Carbon Mix Designs – Develop processes allowing sustainable and innovative concrete materials and admixtures. (Task 1c) Update • Update Specifications & Contracts – Revise concrete specifications and procurement documents to encourage lower-carbon mixes. (Task 2) Report • Report Progress Annually – Provide updates to the Austin City Council. (Task 3) 4 Concrete and Cement Volume Tracking • Started collecting quarterly data since FY23 from concrete producers and internal city departments • CO₂ footprint includes city of Austin and surrounding areas • FY 23: 499,641 CY concrete (Approx.175M lbs CO₂) • FY 24: 516,319 CY concrete (Approx. 174M lbs CO₂ ) • FY 25: 462,790 CY concrete (Approx. 166M lbs CO2) ) Y C ( s d n a s u o h T 540 520 500 480 460 440 420 ) S B L ( S N O I L L I M 195 190 185 180 175 170 165 160 155 150 Citywide Concrete Usage (Cu. Yd) FY 23 FY 24 FY 25 Total Cement Usage and Approx. CO2 Emission 195 193 175 174 184 166 FY 23 FY 24 FY 25 Total Cement Usage (lbs) Approx. CO2 emission (lbs) 5 EPD Implementation Working the Concrete Mix Producers • May 2023 • June 2023 • August 2023 Notified via emails and letter about COA Office of the City Engineer plan to EPD implementation Notified via emails and letters about City Resolution EPD Survey to 12 different producers (3 replied) EPD Submission Timeline • Initial Deadline: October 1, 2024 • Extended Deadline: March 31, 2025 • Letter and email reminders sent August 2023, July 2024, and August 30th, 2024 • March 2025: Final reminder • Volumetric Truck concrete EPD deadline extended to FY 2026 ➢ Lack of an established Product Category Rule (PCR) Effective March 31, 2025, all concrete producers operating within the City of Austin are required to submit product specific Type III EPDs as defined in ISO standard 14025 for their concrete mixes. EPDs must be third-party verified by an accredited organization. EPDs will be reviewed by the OCE to ensure compliance with the established standards and requirements. 6 EPD Data • Effective March 2025, OCE started collecting EPD data from 5 different concrete producers • OCE has already collected more than 500 EPDs for different concrete mixes from 5 major Concrete Producers • Preliminary comparison suggests that City of Austin concrete mixes have lower EPDs than the NRMCA national average Regular Concrete Mix (no Fly Ash) Concrete Mix with Fly Ash Class of concrete Concrete Strength Range (psi) City of Austin Average EPD GWP Per Cubic YD NRMCA National Average EPD GWP Per Cubic YD (kg CO2e) (kg CO2e) Class of concrete Concrete Strength Range (psi) City of Austin Average EPD GWP Per Cubic YD *NRMCA National Average EPD GWP Per Cubic YD (kg CO2e) (kg CO2e) Class J Class B Class D Class A Class I Class C Class S Class 360 Reg Class 360 HRWR 0-2500 0-2500 0-2500 2501-3000 3001-4000 3001-4000 3001-4000 4001-5000 4001-5000 157.7 217.7 216.0 235.0 255.0 274.6 275.0 272.9 308.2 213.7 213.7 213.7 238.1 293.3 293.3 293.3 358.5 358.5 Class J Class B Class D Class A Class I Class C Class S Class 360 Reg Class 360 HRWR 0-2500 0-2500 0-2500 2501-3000 3001-4000 3001-4000 3001-4000 4001-5000 4001-5000 -- 166.0 166.3 183.3 181.0 211.2 209.9 215.7 250.5 -- 169.1 169.1 187.4 229.1 229.1 229.1 278.6 278.6 *30-39% Fly Ash Reference: A Cradle-to-Gate Life Cycle Assessment of Ready-Mixed Concrete Manufactured by NRMCA Members – Version 3.2 7 EPD Comparison with National Average Average EPD: City of Austin vs NRMCA (National Average)* Concrete Mix with No Fly Ash Average EPD: City of Austin vs NRMCA* (National Average) Concrete Mix with Fly Ash ) e 2 O C g k ( D Y c i b u C r e P P W G D P E e g a r e v A 400 350 300 250 200 150 100 50 0 NRMCA National Average EPD, 358 293 293 293 City of Austin Average EPD, 308 275 275 273 238 235 255 214 218 214 216 214 158 ) e 2 O C g k ( D Y c i b u C r e P P W G D P E e g a r e v A 300 250 200 169 150 166 169 166 229 229 229 279 NRMCA National Average EPD, 279 City of Austin Average EPD, 251 187 183 181 211 210 216 100 50 0 Concrete Strength Range (psi) Concrete Strength Range (psi) * Reference: A Cradle-to-Gate Life Cycle Assessment of Ready-Mixed Concrete Manufactured by NRMCA Members – Version 3.2 8 EPD Implementation : Benchmarking • TPW will continue requiring and collecting EPDs from concrete suppliers • TPW is currently working with NRMCA, ACI, and other agencies to establish benchmark EPD requirements (baseline) for each class of concrete mix used in the Austin area • EPD benchmarking establishment expected to be completed by Summer 2026 and will be revised periodically based on industry advancement and required progress to meet sustainability goals 9 Concrete Specification Update TPW has completed draft performance-based concrete specification • Flexibility in water cement ratio (flexibility in mix design) • Use of SCMs • No slump requirement • Requirement for permeability (improve durability) • Flexibility in aggregate gradation with possible use of Optimized Aggregate Gradation (beneficial replacement of cement) (no longer useful) Specifications enable change ~ but Procurement gives it impact (OAG) methods (flexibility in mix design) • QC/QA plan required (assurance of good quality concrete) TPW has distributed draft performance based concrete specification to TACA, internal City departments and concrete producers for the review. Submission for the draft concrete specification to City Rule posting process in 2026 aiming publishing standard specification by 2027. 10 City of Austin Plan Continue Working with Concrete Industry Leaders 11 Use of EPDs in Practice and Public Policy ▪ Promote Education & Awareness Encourage understanding and early adoption while setting practical initial goals. ▪ Develop Fair Purchasing Policies Use Environmental Product Declarations (EPDs) to support economy, equity, and sustainability in procurement. ▪ Prepare for Increasing Performance Targets Build awareness that performance thresholds will tighten to meet 2030 and 2050 climate goals. ▪ Evaluate Sustainability Rating Systems Consider systems such as Institute for Sustainable Infrastructure’s Envision to guide project design, operations, and maintenance using tools like EPDs. Low-carbon concrete is achievable—but only if policy, procurement, and industry work together. 12 Next Steps and Future Outlook • Submit draft concrete specifications through rules posting in 2026 and expect adoption in 2027 • Establish EPD benchmarking in Summer 2026 • Establish a transition plan to accept mixes with industry and city required GWP; work with partners (2026-2027) • Work with purchasing and City project managers to ensure compliance (on-going) • On-going data collection of concrete usage volumes, cement and CO2 emissions (on-going) • Adjust GWP numbers based on analyses of new data (analyze 6-month data and make yearly updates to GWP if needed) 13 Thank You