Drying Shrinkage of Ready-Mixed High-Performance Concrete

Abstract

This paper reports on drying shrinkage undergone by ready-mixed high-performance concrete (HPC). Shrinkage measurements were carried out on concrete specimens as well as on instrumented reference columns. Two different HPC were tested. The first one had a compressive strength of 98 MPa (14,200 psi) at 91 days and the second had a compressive strength of 80 MPa (11,600 psi). The first contained silica fume but the second did not. The effects of the following factors were investigated: curing time, curing conditions, silica-fume content, and water-cementitious materials ratio. It was found that the longer the curing time the lower the drying shrinkage, and that the lower the water-cementitious materials ratio the lower the drying shrinkage. Drying shrinkage of small specimens was compared to that of actual large-sized columns made with these HPC. Shrinkage measured by a conventional laboratory test was found to overestimate shrinkage of HPC in a real structure. The validity of using an American Concrete Institute (ACI) 209 expression derived for ordinary concrete to predict drying shrinkage of HPC was also investigated. It was found that this expression can be used for high-performance concrete only if new parameter values are considered.