A memory-dependent three-dimensional creep model for concrete

Abstract

The study of creep models for concrete is of great significance in analyzing and predicting the long-term stability of concrete structures. Based on the theory of memory-dependent derivatives, memory-dependent viscous dashpots that can describe the characteristics of decaying creep and accelerating creep are constructed based on the varying characteristics of the creep process in different stages. The Kelvin body was replaced with a stable memory-dependent dashpot and the Newtonian dashpot in the visco-plastic body was transformed into an unstable memory-dependent dashpot by drawing on the component combination form of the Nishihara model. A three-dimensional concrete creep model based on memory-dependent derivatives was established. By adjusting the model parameters of stable and unstable memory-dependent viscous dashpots, the model can simulate the creep process of concrete with different decaying creep characteristics and accelerating creep characteristics, and it has good universality. Multiple sets of experimental data on concrete creep verify that the memory-dependent concrete creep model corresponds well to the experimental data. Compared with five other concrete creep models, this model has fewer parameters and higher fitting accuracy, especially in characterizing the accelerating creep characteristics of concrete.