Tensile creep of concrete: Study of its sensitivity to basic parameters

Few data are available concerning tensile creep of concrete, a property that can have considerable influence on shrinkage-induced cracking, for instance in repair works. This paper presents the results of tests carried out to evaluate the influence of stress level, age at loading, steel fiber reinforcement, and paste content on the tensile creep of concrete. These results show that, as in compression, creep of concrete in tension increases sharply under drying conditions. They also show that the tensile creep coefficient decreases with the age at loading, and that up to 50% of the ultimate short-term strength, tensile creep of concrete varies linearly with the applied load, either under sealed or drying conditions. However, tensile creep is apparently more sensitive to fiber reinforcement than compressive creep, and it was observed to increase as the paste content is reduced. Further research is necessary, particularly to determine the ultimate creep capacity, but the. reported data indicate that it could be possible to optimize the composition of cement-based repair materials to reduce their cracking potential when subjected to restrained shrinkage.