This report presents laboratory results from repetitive loads made to evaluate aggregate interlock as a load transfer mechanism at pavement joints. Tests were made to study the influence of aggregate size, hardness, and age at time of joint cracking on load transfer effectiveness. Results indicated that large aggregates were beneficial in maintaining load transfer, especially for larger joint openings. Increasing aggregate hardness was also beneficial. In addition, age of concrete at the time of joint cracking was significant. Early cracking resulted in more aggregate pullouts than later cracking, which resulted in more aggregate fracture. Aggregate pullouts provided better load transfer.
