Concrete 101: Thermal Cracking & Temperature Control in Large Pours

Concrete gets hot as it cures — literally. The chemical reaction between cement and water (called hydration) releases heat. On small jobs, this usually isn’t a problem, but on large pours like foundations, walls, or bridge decks, that heat can cause thermal cracking if not managed properly.

What is Thermal Cracking?

As the concrete heats up in the middle and cools on the outside, different parts of the slab expand and contract at different rates.
This stress can lead to visible cracks on the surface or even deeper inside the structure.

How Contractors Control It

Cooling Pipes: Circulating cold water through pipes placed in the concrete.
Insulation Blankets: Keeping surfaces warm in cold weather so the temperature difference isn’t as extreme.
Placement Timing: Pouring during cooler parts of the day.
Mix Adjustments: Using cement types or admixtures that reduce heat buildup.

Why It Matters

Thermal cracking doesn’t just affect how a project looks — it can impact durability and long-term performance. Proper planning helps keep big pours strong and intact for decades to come.

👉 Behind every massive concrete structure, there’s a careful plan to keep heat under control.

⚠️ Legal Disclaimer:
This blog post is intended for informational purposes only and should not be taken as professional, legal, or construction advice. Every project is unique, and conditions may vary. RLW Concrete LLC is not liable for any actions taken based on this information. Always consult with a qualified professional or attorney for your specific needs.
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