Solidification theory for aging creep

The paper presents a new theory for the basic creep of concrete which takes aging into account in a manner which is better justified physically, better agrees with test results, and is more efficient computationally. The aging is treated as a consequence of volume growth of the load-bearing solidified matter (hydrated cement) whose properties are nonaging and are described by a Kelvin chain with age-independent moduli and viscosities. The thermodynamic restrictions on the aging creep law are satisfied, and the condition of nondivergence of creep curves is met. There are only four free material parameters, and they can be identified from the given test data by linear regression. Deviations from the principle of superposition are also correctly modeled by the theory. Good agreement with typical test data on creep and creep recovery is demonstrated.