Indiana just told the cement industry it won’t accept any blended cement with more than 10% limestone.

That’s a first - and it’s not sitting well with the people who pushed Type IL cement in the first place.


For the first time, a state DOT pushed back on Type IL cement—and the industry fired back. Indiana’s Department of Transportation says it’s protecting performance after bridge decks started scaling. The American Cement Association says the DOT’s new limits are unnecessary, confusing, and unscientific. So, who’s right—and what does it mean for the rest of the country’s concrete?

What You’ll Learn
 • Why INDOT limited Type IL limestone content to 10%
 • The ACA’s objections — and what’s left unsaid
 • How PCA’s 2021 carbon-neutrality roadmap and the federal Buy Clean program accelerated the switch to Type IL
• Why the “one-to-one replacement” claim may have been oversold
• How variable limestone content (≈7.6–12.4%) affects consistency and performance
• Why admixtures and curing aren’t substitutes for good practice
• What INDOT’s maintenance and inspection programs get right
• Why other DOTs may follow Indiana’s lead next

Chapters
 00:00 – Introduction & ACA Briefing Overview
 01:00 – INDOT’s 10% Limit and Industry Response
 04:00 – How Type IL Cement Took Over the Market
 07:30 – PCA Roadmap & Federal Buy Clean Pressure
 10:30 – Complacency and the One-to-One Myth
 14:00 – What Really Drove the 2021–2023 Flip
 18:00 – Cement Chemistry and QC in the Field
 22:00 – The Variability Problem: 7.6% vs 12.4% Limestone
 26:30 – Are Admixtures and Curing the Real Culprits?
 30:00 – INDOT’s Data-Driven Maintenance Approach
 32:00 – Why Other States Are Watching Closely

Guest Info
 Dr. Jon Belkowitz – Chief Technical Officer, Intelligent Concrete
 Email: [email protected]
 Website: https://www.intelligent-concrete.com

Concrete Logic Academy
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 Explore practical courses made for contractors, engineers, and producers.
 Free trial: https://www.concretelogicacademy.com

Support the Podcast
 Support the show and be listed as a Producer for life on the episode page:
 https://www.concretelogicpodcast.com/support

Media & Sponsorship Inquiries: [email protected]

Podcast Partners

Intelligent Concrete
 At Intelligent Concrete, we combine lab precision with field expertise to help you understand what your concrete is telling you. Our services include mix troubleshooting, forensic and petrographic testing, performance-based specification and admixture development, and training for engineers, contractors, and producers. Whether you’re chasing consistency, durability, or answers after a failure, Intelligent Concrete delivers the data and insight to solve problems and improve performance.
 Learn more: https://www.concretelogicpodcast.com/intelligent-concrete

KUIU (Affiliate Link) – https://www.concretelogicpodcast.com/kuiu
15% off the first order.

Credits
Produced by Jodi Tandett & Concrete Logic Media
Music by Mike Dunton — https://www.mdunton.com

Connectivity
Host: Seth Tandett
Concrete Visionary | Business Development at Baker Construction | Host of the #1 Concrete Podcast
LinkedIn: https://www.linkedin.com/in/sethtandett/
YouTube: https://www.youtube.com/@concretelogicpodcast
Website: https://www.concretelogicpodcast.com

If you learned something new, share this episode with your team and help more engineers and builders think logically about concrete.

Until next time, let’s keep it concrete!

Reference Links 

• ACA Briefing: “Portland-Limestone Cement Limits in Indiana Department of Transportation Specifications” (October 2025 Update) — https://tinyurl.com/TypeIL
• INDOT Recurring Special Provision 901-M-069 (Effective December 1, 2025): https://www.in.gov/dot/div/contracts/standards/rsp/sep25/900/901-M-069%20251201.pdf
• INDOT Testing Memos Referenced in ACA Briefing:
   • 21-05 • 22-02 • 23-01 • 24-03 • 25-02 (Available at https://www.in.gov/indot/doing-business-with-indot/contractorsconstruction/division-of-materials-and-tests/current-testing-memos/) 

What if your concrete mix could cut a data center’s power bill by 15%?

In this episode of the Concrete Logic Podcast, host Seth Tandett talks with Frank Stankunas Sr., Frank Stankunas Jr., and James Cordeiro from Silverback Concrete about a concept most engineers haven’t thought about—thermal resistivity in concrete.

They explain how low rho concrete helps data centers shed heat faster, take pressure off the grid, and extend the life of buried electrical infrastructure. You’ll hear how they’re testing mixes that hit rho values in the 20s, why quality control is everything, and why engineers need to stop “copying and pasting” specs from old jobs.

By the end, you’ll see why thermal resistivity may be the next big efficiency play in the world’s fastest-growing utility - data.



What You’ll Learn
• What thermal resistivity (rho) actually measures in concrete.
• How low rho concrete reduces power bills and protects the grid.
• Why inconsistent mixes can cause “thermal runaway” in cables.
• How soil type and aggregate selection affect heat dissipation.
• What testing and verification look like for low rho concrete.
• Why some engineers are still unaware of rho’s importance.
• How Silverback’s “Game Changer” mix is redefining performance.
• What collaboration between engineers and contractors could unlock next.

Chapters
00:00 – Introduction to Thermal Resistivity in Concrete
01:48 – Understanding Thermal Resistivity and Its Importance
05:21 – Comparing Standard Concrete Mixes to Low Rho Concrete
09:08 – Testing and Verifying Thermal Resistivity
12:37 – Quality Control and Consistency in Concrete Mixes
16:22 – The Role of Engineers in Specifying Rho Values
20:05 – Innovative Approaches to Reducing Heat in Data Centers
23:37 – Conclusion and Future Directions for Concrete Technology

Guest Info
Frank Stankunas Sr. – President, Silverback Concrete
[email protected]
 
Frank Stankunas Jr. – Vice President, Silverback Concrete
[email protected]
 
James Cordeiro – Director of Strategic Development, Silverback Concrete
[email protected]
https://www.silverbackconcrete.co



Concrete Logic Academy
Earn your PDHs the logical way.
Explore practical courses made for contractors, engineers, and producers.
Free trial: https://www.concretelogicacademy.com



Support the Podcast
Support the show and be listed as a Producer for life on the episode page:
https://www.concretelogicpodcast.com/support

KUIU Affiliate Link: https://www.concretelogicpodcast.com/kuiu
Media & Sponsorship Inquiries: [email protected]



Podcast Partners
Intelligent Concrete
At Intelligent Concrete, we combine lab precision with field expertise to help you understand what your concrete is telling you. Our services include mix troubleshooting, forensic and petrographic testing, performance-based specification and admixture development, and training for engineers, contractors, and producers.

Whether you’re chasing consistency, durability, or answers after a failure, Intelligent Concrete delivers the data and insight to solve problems and improve performance.
Learn more: https://www.concretelogicpodcast.com/intelligent-concrete



Credits
Produced by Jodi Tandett & Concrete Logic Media
Music by Mike Dunton — https://www.mdunton.com



Connectivity
Host: Seth Tandett
Concrete Visionary | Business Development at Baker Construction | Host of the #1 Concrete Podcast
LinkedIn: https://www.linkedin.com/in/sethtandett/
YouTube: https://www.youtube.com/@concretelogicpodcast
Website: https://www.concretelogicpodcast.com


If you learned something new, share this episode with your team and help more engineers and builders think logically about concrete. 


Until next time, let’s keep it concrete! 

What happens when the concrete industry’s “wonder dust” meets its high-tech rival?

In this episode of the Concrete Logic Podcast, host Seth Tandett brings back Dan McCoy and Dr. Jon Belkowitz to challenge everything we thought we knew about silica fume. From bridge deck overlays that crack like eggshells to the real CO₂ math no one wants to talk about, the guys separate hype from chemistry and ask the only question that matters: What are we really asking this concrete to do?


What You’ll Learn
• What is silica fume really — and how did it end up in our concrete?
• How does colloidal silica change the way concrete performs in the field?
• Why bridge deck overlays using silica fume often fail before their time.
• How mix design mistakes turn silica fume into a “volatile” material.
• Why colloidal silica can actually cost less than silica fume.
• What’s the environmental truth behind “green” cement substitutes?
• Why performance specifications—not recipes—should drive concrete design.
• The one ASTM document every purchaser should actually read.


Chapters
00:00 Introduction and Guest Introductions
01:36 Understanding Silica Fume
05:11 Colloidal Silica vs. Silica Fume
13:38 Practical Applications and Challenges
18:34 Cost Analysis and Environmental Impact
32:52 Exploring Concrete Associations and Data Sources
33:07 Understanding CO₂ Emissions in Concrete Materials
34:34 Debating Environmental Impact of Fly Ash
36:03 The Role of Coal in Concrete Production
38:23 Analyzing Silica Fume vs. Colloidal Silica
40:10 Cost and Benefits of Silica in Concrete
41:23 Challenges in Using Silica Fume
43:03 Evaluating Cost Structures of Concrete Materials
45:22 Understanding Concrete Specifications and Purchaser Requirements
46:56 Concluding Thoughts on Concrete Practices



Guest Info
Dan McCoy, P.E. — R.L. McCoy, Inc.
Email: [email protected]
LinkedIn: https://www.linkedin.com/in/dan-mccoy-48507730/
Website: https://www.rlmccoy.com

Dr. Jon Belkowitz, Ph.D., P.E. — Director of Research, Intelligent Concrete
Email: [email protected]
LinkedIn: https://www.linkedin.com/in/jon-belkowitz-phd-pe-53494719/
Website: https://intelligent-concrete.com



Concrete Logic Academy
Earn PDHs for courses built from real podcast episodes.
Start learning at https://www.concretelogicacademy.com



Support the Podcast
Donate to keep Concrete Logic independent: https://www.concretelogicpodcast.com/support

Shop KUIU gear through our affiliate link: https://www.concretelogicpodcast.com/kuiu

For podcast media services or sponsorships: [email protected]

Podcast Partners

Intelligent Concrete
At Intelligent Concrete, we combine lab precision with field expertise to help you understand what your concrete is telling you. Our services include mix troubleshooting, forensic and petrographic testing, performance-based specification and admixture development, and training for engineers, contractors, and producers. Whether you’re chasing consistency, durability, or answers after a failure, Intelligent Concrete delivers the data and insight to solve problems and improve performance.
Learn more: https://www.concretelogicpodcast.com/intelligent-concrete

Credits
Producers: Jodi Tandett & Concrete Logic Media
Music by Mike Dunton — https://www.mdunton.com



Connectivity
Host: Seth Tandett — Concrete Visionary & Host of The #1 Concrete Podcast
LinkedIn: https://www.linkedin.com/in/sethtandett
YouTube: https://www.youtube.com/@concretelogicpodcast
Website: https://www.concretelogicpodcast.com


Like, subscribe, comment, and share this episode to help more people think critically about concrete. Let's keep it concrete!

What if the problem isn’t your concrete, but how you run your business?
 
In this episode of the Concrete Logic Podcast, Seth Tandett talks with Tamson Omps, Director of Operations at Thomas Concrete, about how ready-mix producers can finally take control of their margins. Tamson lays out the seven areas that make or break profitability in the ready-mix business—from equipment maintenance and driver retention to scheduling and waste management.
 
Whether you manage a single plant or oversee a regional operation, this episode gives you a practical, no-nonsense look at what’s actually driving your profits (and losses) today.

What You’ll Learn
• Why does Tamson say “we don’t sell concrete—we sell truck space”?
• What simple maintenance strategy can save thousands in downtime?
• How can ready-mix companies cut driver turnover by focusing on the right incentives?
• What’s the real cost of a truck sitting on the jobsite?
• How does batching setup and admixture sequencing impact load times and profit?
• What can schedulers do to eliminate wasted hours in the yard?
• How can waste and return concrete be turned into an extra revenue stream?

Chapters
00:00 – Introduction: The Profitability Puzzle in Ready-Mix
01:19 – Shifting Perspective: Concrete as a Service, Not a Product
03:25 – Low Hanging Fruit: Equipment Maintenance
04:36 – People Matter: Keeping Delivery Pros on the Team
08:20 – Truck Turnaround: The Real KPI That Matters
11:02 – Load Times and Plant Flow: Admixtures, Sequencing, and Efficiency
18:16 – Scheduling for Success: Managing Peak Demand
22:54 – Waste Management: Turning Returns into Revenue

Guest Info
Tamson Omps
Director of Operations, Thomas Concrete
Email: [email protected]
LinkedIn: https://www.linkedin.com/in/tamson-omps-mba/
Company: Thomas Concrete – https://www.thomasconcrete.com

Concrete Logic Academy

Earn PDHs the easy way. Listen to podcast episodes, complete a short quiz, and get professional development hours with proper documentation.
Start your free trial: https://www.concretelogicacademy.com

Support the Podcast

This show runs on a Value-for-Value model. If you got value from this episode, consider supporting us:
https://www.concretelogicpodcast.com/donate

Support the show while gearing up with KUIU premium outdoor gear—what Seth wears both on the hunt and on the job. Shop through this link at no extra cost: https://www.concretelogicpodcast.com/KUIU

Want help with media services like podcasting or YouTube for your concrete company? Reach out to Seth at [email protected].

Credits

Producers: Jodi Tandett and Concrete Logic Media
Music by Mike Dunton – https://www.mdunton.com

Connectivity

Host: Seth Tandett – Concrete Visionary & Business Development Manager at Baker Construction
LinkedIn: https://www.linkedin.com/in/sethtandett
YouTube: https://www.youtube.com/@concretelogicpodcast
Website: https://www.concretelogicpodcast.com

Don’t forget to like, subscribe, comment, and share. Let’s keep it concrete.

• Why are workers staying longer instead of chasing new jobs?
• Is relocating still worth it in today’s construction market?
• What red flags should candidates look for when evaluating opportunities?
• How can recruiters use advanced communication to stand out?
• What do market cycles reveal about job security and loyalty in construction?

Mass timber is often promoted as faster, cheaper, and greener—but does it really hold up against concrete?

In this episode of the Concrete Logic Podcast, we examine where timber actually competes, where it falls short, and what owners and engineers need to know before choosing it over concrete. From speed and aesthetics to fire ratings, insurance, and durability, this conversation exposes the tradeoffs that get lost in the marketing.


What You'll Learn
- What exactly qualifies as mass timber, and why is CLT the dominant product?
- Can timber’s speed of construction outweigh prefabrication challenges?
- Why do acoustics and fire safety force timber to rely on concrete toppings?
- How do insurance and durability concerns stack up against concrete?
- Are sustainability claims for timber real—or just another sales pitch?
- Where does concrete still deliver advantages timber can’t match?


Chapters
00:00 – Introduction to Mass Timber and Concrete
04:38 – Understanding Mass Timber Products
09:00 – Advantages of Mass Timber in Construction
13:40 – Design Considerations and Aesthetics
18:22 – Durability, Maintenance, and Sustainability
22:48 – Cost, Insurance, and Market Trends


Guest Info
Name: Garrett Braun
Email: [email protected]
Website: https://www.blueneststructural.com/
Company: Blue Nest Structural



Concrete Logic Academy
Earn PDHs the easy way. Listen to podcast episodes, complete a short quiz, and get professional development hours with proper documentation.
Start your free trial: https://www.concretelogicpodcast.com/academy



Support the Podcast
This show runs on a Value-for-Value model. If you got value from this episode, consider supporting us: https://www.concretelogicpodcast.com/donate

Support the show while gearing up with KUIU premium outdoor gear—what Seth wears both on the hunt and on the job. Shop through this link at no extra cost: https://www.concretelogicpodcast.com/KUIU

Want help with media services like podcasting or YouTube for your concrete company? Reach out to Seth at [email protected].



Credits
Producers: Jodi Tandett and Concrete Logic Media


Music by Mike Dunton: https://www.mdunton.com/



Connectivity
Host: Seth Tandett, Concrete Visionary & Business Development Manager at Baker Construction


LinkedIn: https://www.linkedin.com/in/sethtandett


YouTube: https://www.youtube.com/@concretelogicpodcast


Website: https://www.concretelogicpodcast.com


Don’t forget to like, subscribe, comment, and share. Let’s keep it concrete.

What if sunlight alone—not heat—was silently destroying your concrete? 

In this episode of the Concrete Logic Podcast, Seth Tandett and Bob Higgins uncover a groundbreaking MIT study that reveals evaporation can be driven by light, not just temperature. This discovery doesn’t just change climate models—it could explain why concrete in the field fails in ways labs never predict. From sublimation and surface chemistry to curing practices and accountability, this episode forces the industry to face a missing piece of science hiding in plain sight.

What You'll Learn
- Can light alone drive evaporation—and what does that mean for concrete curing?
- Why does cold-weather curing produce more durable concrete?
- Is sublimation the hidden culprit behind freeze–thaw damage?
- How does surface relative humidity affect cement formation efficiency?
- Why do laboratory tests keep producing results that don’t match the field?
- Could pigmented curing compounds or internal curing be the next solution?
- Are installers being unfairly blamed for failures tied to ignored science?


Chapters
00:00 – Introduction: Concrete Climate and Missing Science
01:44 – MIT’s Light-Driven Evaporation Discovery
05:41 – Why This Matters for Concrete Durability
11:35 – Relative Humidity and Cement Formation
17:24 – Sunlight, Chemistry, and Curing Practices
23:13 – Future Directions and Industry Accountability



Guest Info
Name: Bob Higgins
Email: [email protected]
Webpage: https://www.concretelogicpodcast.com/guests/robert-higgins/
Company: Independent Concrete Consultant



Concrete Logic Academy
Looking for practical, real-world education in concrete? Get your first PDH course FREE at the Concrete Logic Academy: https://www.concretelogicpodcast.com/academy


Support the Podcast
This show runs on a Value-for-Value model. If you got value from this episode, consider supporting us: https://www.concretelogicpodcast.com/donate


Support the show while gearing up with KUIU premium outdoor gear—what Seth wears both on the hunt and on the job. Shop through this link at no extra cost to you: https://www.concretelogicpodcast.com/KUIU


Want help with media services like podcasting or YouTube for your concrete company? Reach out to Seth at [email protected].



Credits
Producers: Jodi Tandett and Concrete Logic Media

Music by Mike Dunton: https://www.mdunton.com/

Connectivity
Host: Seth Tandett, Concrete Visionary & Business Development Manager at Baker Construction

LinkedIn: https://www.linkedin.com/in/sethtandett

YouTube: https://www.youtube.com/@concretelogicpodcast

Website: https://www.concretelogicpodcast.com 

Don’t forget to like, subscribe, comment, and share. Let’s keep it concrete. 

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!

• What exactly is AI and a large language model (and why should concrete pros care)? 
• How can field leaders use AI to turn jobsite chaos into clear, professional communication? 
• What practical AI tools exist today for handling manuals, SDS sheets, specs, and safety talks? 
• Why are “gray collar” trades positioned uniquely in the AI shift? 
• How will AI impact the traditional career ladder for project engineers and assistant PMs? 
• Is AI really taking jobs—or just changing how we use people on jobsites? 
• How can companies re-skill and re-align their workforce to get ahead of this shift? 
  
  

• Why do so many people still believe Type IL is a one-to-one replacement? 
• What’s the real impact of outdated admixtures on today’s cement? 
• How do compatibility tests help prevent concrete failures? 
• Why are some producers thriving with Type IL while others are falling behind? 
• What questions should ready-mix suppliers be asking their admixture reps? 
• Are outdated specifications setting projects up to fail before they start? 
• How is complacency contributing to early-age concrete failures?