Tensile Creep and Cracking Resistance of High-Strength Concrete with Shrinkage Reducing Admixture under Uniaxial Restrained Condition at Early Age

Abstract

High-strength concrete (HSC) has been widely used in various engineering structures due to its excellent mechanical properties. However, the low water/cement ratio in HSC causes greater shrinkage and increases the cracking potential under restrained condition. Shrinkage reducing admixture (SRA) is extensively applied due to its excellent performance in reducing shrinkage. Although the influence of SRA on the mechanical properties and drying shrinkage has been investigated, investigations on tensile creep and cracking resistance are still lacking. Investigations on the tensile creep, autogenous shrinkage, restrained stress, and cracking resistance of HSC with SRA were conducted under uniaxial restrained condition in the current research. Four groups of mixtures with different dosages of SRA were tested under adiabatic conditions by utilizing temperature stress test machine. The experimental and analytical findings indicated that (1) the addition of SRA reduced the temperature rise and cracking temperature of HSC under adiabatic conditions; (2) the autogenous shrinkage and basic tensile creep of HSC decreased when the dosages of SRA increased; (3) the cracking time, cracking temperature drop, and cracking stress of HSC increased when the dosages of SRA increased; and (4) the cracking resistance of HSC increased with the increase of SRA dosages.