EP #162: Why This Concrete Expert Wants Air Out of Exterior Slabs

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ON THIS EPISODE OF THE CONCRETE LOGIC PODCAST

Does exterior concrete always need entrained air to survive freezing and thawing?

Seth is joined by Jason Adams, founder and CEO of Mega Slab, to challenge that long-standing practice. Jason argues that a properly designed, highly dense concrete system may limit water intrusion enough to reduce the need for entrained air.

Seth presses on the risks, including mix design, workability, finishing, curing, and specification requirements. Jason makes clear that he is not recommending contractors simply remove air from a standard mix. His approach depends on treating the concrete as a complete system.

The episode asks a practical question: Should exterior concrete be designed to give freezing water room to expand, or should the priority be keeping water out in the first place?

WHAT YOU’LL LEARN

What air entrainment is intended to do during freeze-thaw exposureThe difference between entrained air and naturally entrapped airWhy Jason believes entrained air can reduce concrete densityHow dense concrete may limit water and chloride intrusionWhy removing air from a standard exterior mix is not enoughHow aggregate packing and optimized mix designs affect permeabilityWhy air-entrained concrete should not be hard-trowel finishedHow entrained air can affect workability and finishingWhy specifications and established practices may resist this approachWhat field performance Jason has observed in Midwestern pavementsWhy mix design, placement, finishing, curing, and fibers must work as a system

CHAPTERS

(00:00) Introduction and support for the show

(03:24) Jason Adams and the air-void question

(04:56) Freeze-thaw testing and ASTM standards