Dimensional Stability of Grout-Type Materials Used as Connections between Prefabricated Concrete Elements

Prefabricated bridge elements and systems (PBES) construction relies on field-cast, grout-type materials to complete the connections between precast concrete elements. This PBES construction facilitates and accelerates bridge construction (ABC), increases safety, and minimizes the inconveniences to the traveling public while delivering a superior product. Although prefabricated concrete components are produced in a controlled environment, field-cast grouts have at times shown serviceability issues mainly associated with dimensional stability. This paper assesses the dimensional stability (primarily shrinkage) of a total of seven prebagged grouts currently used in the construction industry. Their shrinkage performance is compared to that of an ultrahigh-performance concrete. The feasibility of the test methods used for evaluating the dimensional stability of nonshrink grouts is also discussed. Although many grouts are referred to as nonshrink materials, the results show shrinkage, especially in drying conditions. The use of the internal curing technology as an emerging solution for mitigating shrinkage in grout-type materials is also discussed. The results obtained in two of the cement-based grouts, including internal curing, show a reduction of both autogenous and drying shrinkage. Based on the results obtained, recommendations are given to end-users to provide guidance in selecting an appropriate grout-type material.