Dowel bars in concrete pavements exhibit behavior similar to piles in soil subjected to lateral loads. Joint failure can occur either through the yielding of the steel dowel bar under bending stress or by the crushing of concrete due to excessive bearing stress.
Achieving an optimal spacing and length for dowel bars is crucial. Overly close spacing can hinder construction, while excessive spacing might lead to bending between the bars, compromising their load-transferring efficiency. Regarding length, excessively long dowel bars result in minimal stress at their ends, rendering them ineffective in transferring loads between adjacent panels. Conversely, overly short dowel bars concentrate stress at the joint face, increasing the risk of concrete crushing.
This understanding of dowel bar behavior and its relationship to joint performance is supported by the Ministry of Transport’s 1955 research, which provides valuable insights for optimizing dowel bar design in concrete pavements. By carefully considering factors such as spacing and length, engineers can ensure the dowel bars effectively distribute loads, prevent joint failure, and maintain the long-term integrity of the pavement.