Time-Dependent Properties of Ultrahigh-Performance Concrete: Compressive Creep and Shrinkage

Abstract

Ultrahigh-performance concrete (UHPC) is a new class of concrete, differentiated from conventional concrete by clear distinctions in its material behaviors. Understanding and managing time-dependent properties is necessary for the appropriate use of any concrete-like material. This study investigated the time-dependent properties of a suite of commercially available UHPC-class materials, with the goal being to characterize the behaviors then propose predictive performance models. To achieve the goal of this study, compressive creep and shrinkage experiments encompassing different environmental conditions were completed. The objectives of this research were as follows: (1) quantify the compressive creep behavior of different UHPC-class materials; (2) assess the effects of strength, maturity, and loading age on UHPC creep and develop predictive equations; (3) investigate unrestrained shrinkage behaviors of UHPC-class materials; (4) evaluate the effects of different environments, including low-humidity and high-humidity and sealed conditions, on compressive creep and unrestrained shrinkage of different UHPC-class materials and develop predictive equations; and (5) determine the coefficient of thermal expansion (CTE) of UHPC-class materials at different ages.