If contraction joints are cut too soon the joint may ______ but if too late random __________ can occur.

If contraction joints are cut too soon the joint may ______ but if too late random __________ can occur.

• A. reveal, random cracks
• B. reveal, continuous cracks
• C. peel, random cracks
• D. split, random cracks

Answer: (A)

Contraction joints are timed to control where cracks form as concrete dries and temperatures change. If you cut too soon, the surface is still soft, and the cutting action can gouge or pull away the paste, revealing the underlying aggregate at the joint. That’s why the joint may reveal the aggregate. If you wait too long, the concrete has already begun cracking from shrinkage and temperature effects, so cracks form at random locations instead of along the planned joint. So the correct pairing is that cutting too soon may reveal, while cutting too late allows random cracks to occur.

Contraction joints are timed to control where cracks form as concrete dries and temperatures change. If you cut too soon, the surface is still soft, and the cutting action can gouge or pull away the paste, revealing the underlying aggregate at the joint. That’s why the joint may reveal the aggregate. If you wait too long, the concrete has already begun cracking from shrinkage and temperature effects, so cracks form at random locations instead of along the planned joint. So the correct pairing is that cutting too soon may reveal, while cutting too late allows random cracks to occur.