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Saw a sidewalk in Seattle that made me rethink expansion joints
It was a 40 foot pour with joints every 6 feet, but the slab still cracked right down the middle of a panel. Has anyone else seen that happen with proper spacing?
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ryan_hart388d ago
Sounds like a subgrade issue, not the joints.
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xenam848d ago
Actually had the same thing happen with my patio. They cut perfect control joints, but the slab still cracked inside one. Contractor said sometimes the mix itself can shrink more in one spot if it dries too fast, pulling apart from the inside. So joints help, but they don't stop every single crack.
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luna2618d ago
We had a 30 foot driveway pour done with joints every 5 feet. I always figured that was the textbook way to do it. Then last winter a crack opened up right through the center of a square, just like your pic. It made me realize the ground underneath can move more than the joints can handle sometimes.
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