Question

What is the minimum depth of contraction joints in concrete?

1 - 10% of slab
2 - 15% of slab
3 - 25% of slab (1/4 of slab)
4 - 33% of slab"

Answer 1

The minimum depth of contraction joints in concrete is typically recommended to be 1/4 of the slab thickness or 25% of the slab. These joints help to control cracking and improve the durability of the concrete.

Step-by-step explanation:

The minimum depth of contraction joints in concrete is typically recommended to be 1/4 of the slab thickness or 25% of the slab. This means that if the slab is 4 inches thick, the minimum depth of the contraction joint should be 1 inch. Contraction joints are designed to control the cracking that occurs due to shrinkage of the concrete as it hardens.

These joints help to divide the slab into smaller sections, allowing for the movement and expansion of the concrete without causing significant cracks. By providing a weaker point in the slab, the risk of random cracks forming across the entire slab is reduced, promoting better long-term durability.

It is important to note that the exact depth of contraction joints may vary depending on factors such as the climate, slab thickness, and intended use of the concrete.