Solidification theory and mechanisms of aging creep of concrete

Continuous retardation spectrum for the Kelvin chain model can be used for concrete creep analysis. This spectrum can be determined by the asymptotic transformation method, which is applicable for any creep law. By this method, a unique retardation spectrum can be obtained from the given compliance function. Application to the log-power creep law reveals that for concrete, the asymptotic retardation spectrum of order 3 is sufficiently accurate in practice. For small values of the time exponent which are typical of concrete, the spectrum can be simplified and still describe the compliance function satisfactorily. By discretization of the continuous retardation spectrum, a rate-type formulation for concrete creep can be obtained.