Back in 2011, the industry said portland-limestone cement (PLC) came with “no significant risks.” By 2024, the updated report admits higher carbonation rates, chloride ingress concerns, admixture sensitivity, and tighter curing demands. In this solo episode, Seth lays out what actually changed between the 2011 and 2024 reports, what the case studies do—and don’t—prove, and asks the blunt question: would PLC be this widespread without the CO₂ storyline? What You’ll Learn - What the 2011 report promised vs. what the 2024 report now admits. - How carbonation, chloride ingress, admixture control, and curing show up in the latest findings. - What the project examples (PCA exposure site, Utah DOT bridges, Texas pavements, European jobs) really say. - Claimed upsides beyond CO₂: energy savings, workability, and mass concrete heat benefits. - Why PLC is less forgiving than Type I/II—and what that means on real jobs. - The big question: is PLC an innovation or a policy-driven shift? Chapters 00:00 – Welcome, solo setup, and callback to EP #126 00:30 – Why revisit PLC? ACA’s comment and the 2024 report 02:00 – Blended cement usage spike: under 10% to ~65% in a few years 03:00 – 2011 → 2024: from “no risk” to “manageable issues” 05:00 – Admixtures/air, SCMs, and curing: where sensitivity shows up 07:00 – Positives claimed beyond CO₂: energy, workability, mass concrete 08:30 – What case studies actually show (PCA prisms, Utah bridges, Texas pavements, Europe) 12:00 – PLC is less forgiving: tighter margins than Type I/II 13:30 – What’s still missing: long-term (50–100 yr) performance proof 15:30 – Would PLC exist without the CO₂ narrative? 16:30 – Support the show + open invite for guests 17:30 – Outro Concrete Logic Academy Want to go further? Courses and PDHs for concrete pros: https://www.concretelogicacademy.com Support the Podcast If this helped you think differently about concrete, consider supporting the show: - Donate: https://www.concretelogicpodcast.com/donate - Kuiu gear (affiliate link): https://kuiu.sjv.io/Z6D1XW - Looking for media help—podcasting, YouTube, or storytelling for your concrete company? Reach out to Seth at
[email protected] to learn more. Credits Produced by Jodi Tandett & Concrete Logic Media Music by Mike Dunton ( https://www.mdunton.com/) Stay Connected Host: Seth Tandett, Concrete Visionary & Industry Expert LinkedIn: https://www.linkedin.com/in/sethtandett YouTube: https://www.youtube.com/@concretelogicpodcast Website: https://www.concretelogicpodcast.com Don’t forget: Like, subscribe, comment, and share this episode to help spread the word. Let’s keep it concrete!
