In this episode of the Concrete Logic Podcast, Seth Tandett interviews Colin Lobo, the Executive Vice President and Division Head of Engineering at NRMCA. They delve into the differences between prescriptive and performance specifications in concrete, discussing the implications of each on responsibility, compliance, and industry practices. Colin explains the evolution from prescriptive to performance specifications, the challenges of hybrid specifications, and the importance of accurate documentation in concrete mixing. The conversation highlights the challenges faced in job site testing, the importance of density measurement, and the need for improved testing standards to ensure safety and sustainability. The discussion also touches on the shift towards performance-based specifications and the confidentiality issues surrounding mix designs.Takeaways • Prescriptive specifications dictate how to mix concrete. • Performance specifications focus on the desired outcomes. • Responsibility shifts to the concrete producer with performance specs. • Hybrid specifications can create contradictions in requirements. • Water quality is a significant concern in concrete mixing. • Testing specimens often get compromised, affecting strength measurements. • Current testing standards are inadequate and need improvement. • Sustainability efforts could be increasing the carbon footprint of concrete. • Industry standards must evolve to reflect practical realities. • Collaboration is needed to improve testing and standards. • Engagement in standards committees is vital for industry progress. Chapters 00:00 Introduction to Concrete Specifications 03:25 Understanding Prescriptive vs Performance Specifications 07:30 The Shift in Responsibility 09:50 Hybrid Specifications and Their Challenges 11:46 The Role of Legal in Specification Acceptance 13:24 Concrete Producer's Perspective on Specifications 15:09 Documenting Compliance in Concrete Mixing 16:40 Typical Prescriptive Requirements 19:24 Evolution from Prescriptive to Performance Specifications 21:20 Challenges in Concrete Testing 24:29 Mix Design and Performance Expectations 27:27 The Importance of Density Measurement 29:52 Addressing Testing Standards and Sustainability 32:19 Evolving Towards Performance-Based Specifications 35:18 Confidentiality and Industry Standards***Did you learn something from this episode? Would you like to support the concrete industry's favorite podcast? If so, donate at https://www.concretelogicpodcast.com/support/⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ . When YOU donate to the show, you will be listed as a producer of the next episode that is released! Join the Concrete Logic Academy! Enhance your learning from our podcast with engaging quizzes that test your knowledge and help you earn Professional Development Hours (PDHs). Support Concrete Logic and take your education to the next level! 🚀  FIND OUT MORE HERE: https://www.concretelogicacademy.com/  ***  Episode ReferencesGuest: Colon Lobo, Executive VP of NRMCA, clobo@nrmca.orgGuest Website:⁠  https://www.nrmca.org/Producers: Jodi Tandett, Mike HernandezDonate & Become a Producer: ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠https://www.concretelogicpodcast.com/support/⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠Music: Mik