Pavement Design MCQ with answer and solution

Concept

Longitudinal joints in concrete pavements are held together by tie bars so the slabs do not separate.

Step-by-step solution

1. Longitudinal joints divide the pavement into lanes along the road length. 2. These joints must stop the two slabs from moving apart and stop one slab from settling more than the other. 3. Tie bars (deformed steel bars) are placed across the joint at mid-depth to tie the slabs together. 4. So the answer is tie bars.

Explanation

Longitudinal joints control cracking along the length of a wide concrete pavement. Tie bars are put across these joints to hold the two slabs together and keep the joint tight. Dowel bars are used at transverse joints (mainly expansion and contraction joints) to transfer load, not at longitudinal joints.

Why the other options are wrong

B: Torsion rods are not used in CC pavement joints. C: Small spacing is not a joint device; it is not a correct answer. D: Shear rods are not a standard term for pavement joints; load transfer at transverse joints is by dowel bars.

Shortcut

Longitudinal joint = Tie bar; Transverse joint = Dowel bar.

Common mistake

Students mix up tie bars and dowel bars. Dowel bars transfer load at transverse joints, while tie bars hold slabs together at longitudinal joints.