WHAT IS THE DOWEL BAR?
Dowel bars are short, round, and smooth steel bars used to provide a mechanical connection between slabs without restricting horizontal joint movement. These bars are mainly used in jointed plain concrete pavement (JPCP) to reduce the additional stress and loss induced due to the moving vehicle.
SIZE OF DOWEL BAR
The size of the dowel bar depends on the thickness of the pavement. Usually, these bars are approx. 1 meter long, 16mm to 25mm in diameter, and spaced 300 mm apart. Dowel bars are usually made of stainless steel or epoxy coated to protect the rods from corrosion.
Half of the length of this bar is embedded in one of the concrete slabs and the remaining portion is bonded in the other adjacent slab. One end of the bar is kept free for movement during expansion and contraction of the slab due to a change in temperature. We place a dowel bar which must be parallel to the centerline. We have to make sure that the new channel must be cut so that at least one-half dowel can be on each side of the joint or crack.
USES/PURPOSE/ADVANTAGES OF DOWEL BARS
- It transfers load without restricting horizontal joint movements due to temperature and moisture expansion and contraction in the concrete slabs.
- It increases the load-carrying capacity of slabs.
- Dowels bars play a role in the horizontal and vertical alignment of slabs.
- It reduces joint faulting and corner cracking.
- Dowels bars improve the performance of pavement joints.