Creep and Shrinkage Law for Concrete at Variable Humidity

Structural analysis with complex constitutive laws has been made feasible. by electronic computers, but for many materials realistic constitutive laws themselves are unavailable at present. This is certainly true in the case of creep and shrinkage of concrete at variable humidity. An experimentalist may point out that better controlled and better designed experiments are needed to enhance the knowledge. Yet, this is only a part of the answer. Perusing the literature, one cannot deny that a vast pool of experimental information already exists, but it remains largely untapped as far as the quantitative theoretical model is concerned. Although 'numerous studies have been devoted to moisture effects in concrete, no consistent constitutive law for concrete creep and shrinkage at variable humidity has yet been identified from the test data, to the best of writers ' knowledge, and this task is chosen as the object of this study. The problem is made difficult partly by the fact that the standard test specimens are during the test in a nonhomogeneous state, i.e., in a state of nonuniform stress, strain, and pore humidity. Mathematically, one faces a so-called invers