Why are joints needed in concrete pavements?

Why are joints needed in concrete pavements?

• A. To increase load transfer between slabs.
• B. To control cracking from shrinkage and temperature changes.
• C. To allow water drainage.
• D. To create decorative patterns.

Answer: (B)

Joints are used to manage cracking caused by shrinkage and temperature changes. As concrete dries it shrinks, and when slabs are restrained by surrounding materials, tensile stresses develop that would cause random cracks. Joints create planned weaknesses at regular intervals, so cracks form along the joints rather than through the slab, keeping the pavement smooth and durable. They also allow slabs to move with temperature changes and enable construction joints to tie into new pours. While joints can be designed to transfer loads across them with dowels, the primary purpose is to control crack formation from shrinkage and temperature effects, not drainage or decoration.

Joints are used to manage cracking caused by shrinkage and temperature changes. As concrete dries it shrinks, and when slabs are restrained by surrounding materials, tensile stresses develop that would cause random cracks. Joints create planned weaknesses at regular intervals, so cracks form along the joints rather than through the slab, keeping the pavement smooth and durable. They also allow slabs to move with temperature changes and enable construction joints to tie into new pours. While joints can be designed to transfer loads across them with dowels, the primary purpose is to control crack formation from shrinkage and temperature effects, not drainage or decoration.