What type of dowel bars are to be used for PCCP?

Plain bars are used as dowel bars in Plain Cement Concrete Pavements (PCCP) primarily because they provide a simplified method for transferring loads between adjacent slabs while allowing for horizontal movements due to temperature changes and shrinkage. The smooth surface of plain bars minimizes friction and allows for slight movements, which is essential in preventing crack propagation and maintaining structural integrity.

Using plain bars also ensures that the interface between slabs can accommodate some degree of vertical and horizontal displacement without any significant restraint, which is crucial in pavement design. Additionally, plain bars are often less costly and easier to handle compared to other types of dowel bars, making them a practical choice in standard applications.

In contrast, threaded bars, coated bars, and reinforced bars have specific applications and characteristics that do not align with the fundamental design requirements for dowel bars in PCCP. While each of these bar types may serve important functions in construction, they are not suited for the specific load transfer and movement characteristics required in PCCP applications.