Experiments on drying shrinkage and creep of high performance hybrid-fiber-reinforced concrete

Abstract

Drying shrinkage can cause high performance concrete (HPC) to crack, resulting in a reduction of its overall strength and durability. Creep behavior is also an important property of HPC and it should also be considered in applications. This paper evaluates the time-dependent creep and shrinkage properties of HPC as well as high performance hybrid-fiber-reinforced concretes (HPHyFRC) through experimental programs and the results will be compared with some common prediction models. The authors’ HPC were developed by using certain percentages of silica fume (SF) and ground granulated blast-furnace slag (GGBS) as cement replacement materials. Double hooked-end steel fibers, single hooked-end steel fibers, and polyvinyl alcohol fibers were mixed in different proportions in the concrete to get HPHyFRC. The total combined volume fractions of the fibers were 0%, 0.6%, and 1.2%. The results indicate that the substitution of ordinary Portland cement (OPC) with SF or GGBS improved the properties of concrete. The addition of fibers significantly reduced the drying shrinkage and creep coefficient of HPHyFRC. While the fiber volume fraction had an insignificant influence on the drying shrinkage of HPHyFRC, hybridization of polyvinyl alcohol fiber with steel fibers resulted in the minimum shrinkage strain. The least creep coefficient was attained by the concrete mix containing 1.2% double hooked-end steel fibers. The CEB-FIP 2010 model predicts the time-dependent behaviors of concretes with the best accuracy among different models compared in this study.