High strength, non-shrink grout has been used to fill the longitudinal keyway joints between girders during the construction of precast, prestressed decked bulb-tee (DBT) girder type bridges. In Alaska, however, past experiences indicated that laboratory grout testing results (e.g., 28-day compressive strength), especially when tested using cube specimens, had large variations. Since the longitudinal joints of DBT girders are crucial to the integrity of a bridge (e.g., providing for the distribution of live load between adjacent girders), it is necessary to investigate why the test results of high strength grout show such variability, which is the main objective of this study. In addition, this study further explores methods to reduce this variability, providing a more constructible and contractually administrable procedure to satisfy the quality and durability needs of bridge keyways that are ‘grouted’.
For more information, please review the Project Information document.