Common Slab Failures and Causes

Thickness is only one input. When slabs fail, it’s often due to base, drainage, joints, or curing.

1) Random cracking

• Cause: no joints, late cutting, excessive water in mix, hot/windy placement.
• Reduce risk: joint plan, correct cure, minimize water, use wind breaks and curing compound.

2) Settlement and differential movement

• Cause: poor compaction, soft spots, inadequate base.
• Reduce risk: remove organics, compact in lifts, proof-roll, stabilize weak soils.

3) Spalling / scaling

• Cause: freeze/thaw exposure, deicing salts, high water-cement ratio, finishing too wet.
• Reduce risk: air entrainment where required, proper finishing, correct PSI/mix design.

4) Curling

• Cause: moisture/temperature gradients, mix and curing issues.
• Reduce risk: uniform curing, correct thickness, appropriate reinforcement and joints.