Shrinkage cracking of high-strength concrete

Pozzolanic materials, along with high-range water-reducing admixtures, have improved strength and durability of concrete construction. Since compressive strength is the most commonly used parameter to describe the quality of concrete in practice, high-strength concrete, often called high-performance concrete, has been used in many structures that ave sensitive to shrinkage cracking. No systematic study has been performed to assess the restrained shrinkage cracking behavior of high-strength concrete. This paper presents research on the restrained shrinkage cracking on several strength levels of concrete. Higher strength levels were obtained by partial substitution of cement with silica fume and by reducing the water content. Ring-type specimens were used for restrained shrinkage cracking tests. Free shrinkage, creep, weight loss, compressive, and splitting tensile strength were also investigated. Results indicate that the free shrinkage for different concretes does not depend on the unit water content or weight loss and that high-strength silica fume concrete shows higher shrinkage and lower creep. Cracking for high-strength silica fume concrete develops much faster and is significantly wider than that of normal-strength concrete.