Abstract Concrete shrinkage is a key factor affecting the serviceability and durability of bridge structures, particularly in elements such as decks, girders, and piers where restrained shrinkage can lead to cracking and long-term performance issues. The incorporation of supplementary cementitious materials (SCMs), such as fly ash and ground granulated blast furnace slag (GGBFS), significantly influences shrinkage behaviour. In addition, environmental conditions commonly encountered on bridge construction sites—such as elevated temperature, low relative humidity, and wind—can accelerate moisture loss, increasing the risk of shrinkage-induced cracking. This study investigates the total shrinkage of nine concrete mixes with 28-day compressive strengths ranging from 30 to 70 MPa, incorporating binder compositions of 30% fly ash, 40% slag, and 60% slag. Specimens were exposed to controlled environmental conditions to quantify the effects of temperature, humidity, and wind on shrinkage development. Based on experimental results, a new predictive model is proposed to estimate total shrinkage under harsh “field conditions” from shrinkage measured or calculated under standard laboratory conditions (23°C and 50% relative humidity). The results indicate that shrinkage under harsh conditions initially increases to a peak before gradually converging to standard-condition values at a defined “merging time.” While binder composition had only a marginal effect on this trend, compressive strength significantly influenced the merging time, which increased with higher strength levels. The proposed model demonstrates excellent predictive capability for concretes with compressive strengths between 30 and 70 MPa, including mixes with 100% general-purpose cement and SCM-blended binders. These findings provide a practical tool for bridge engineers to account for environmental effects on shrinkage, improving serviceability design and reducing the risk of early-age cracking in bridge structures.
Lin et al. (Sun,) studied this question.