MOSAIC: An Effective FFT-based Numerical Method to Assess Aging Properties of Concrete

Abstract

As the nuclear fleet in the United States ages and subsequent license renewal applications grow, the prediction of concrete durability at extended operation becomes more important. To address this issue, a Fast-Fourier Transform (FFT) method is utilized to simulate aging-related degradation of concrete within the Microstructure Oriented Scientific Analysis of Irradiated Concrete (MOSAIC) software. MOSAIC utilizes compositional phase maps to simulate damage from radiation-induced volumetric expansion (RIVE), applied force, creep, and thermal expansion. This compositional detail allows each mineral in the microstructure to be assigned specific material properties, allowing the simulation to be as accurate and representative as possible. The principal goal of MOSAIC is to simulate the effects of nonlinear aging mechanisms occurring in nuclear concrete on the macroscopic mechanical properties, using only the aggregate microstructure compositional information as a starting point. Several realistic example simulations are shown to demonstrate the utility and uniqueness of the MOSAIC software.

Methodological guidelines on concrete degradation based on predictive models and the release of MOSAIC for industry use

“…"MOSAIC utilizes compositional phase maps to simulate damage from radiation-induced volumetric expansion, applied force, creep, and thermal expansion. This compositional detail allows each mineral in the microstructure to be assigned specific material properties, allowing the simulation to be as accurate and representative as possible.The principal goal of MOSAIC is to simulate the effects of nonlinear aging mechanisms occurring in nuclear concrete on the macroscopic mechanical properties, using only the aggregate microstructure compositional information as a starting point" [5].…”

Microstructural Simulation of Ion-Irradiated Natural Rocks and Minerals

“…Using fast-Fourier transform (FFT)-based simulation methods [20,21,11], MOSAIC makes it possible to run efficient mechanical simulations of complex microstructures and to derive their effective mechanical behavior assuming periodic boundary conditions. The capabilities of MOSAIC are fully described in the paper by Torrence et al [26]. The current maximum pixel size of a 2D microstructure is limited to 1,024 × 1,024.…”

Radiation-induced Alteration of Meta-chert

“…2) Investigation of aggregate expansion considering the inhomogeneous volume expansion of rock-forming minerals (Elleuch et al 1972;Hilsdorf et al 1978;Denisov et al 2012;Maruyama et al 2017b;Štemberk 2021a, 2021b). 3) Deriving concrete degradation as a function of aggregate expansion (Dubrovskii et al 1966a(Dubrovskii et al 1966b(Dubrovskii et al , 1968(Dubrovskii et al , 1970Elleuch et al 1972;Hilsdorf et al 1978;Denisov et al 2012;Giorla et al 2015;Le Pape et al 2015, 2016Pomaro 2016;Maruyama et al 2017b;Li et al 2020;Sasano et al 2020;Saklani et al 2021;Torrence et al 2021;Pomaro et al 2022). 4) Performance evaluation of reinforced concrete members considering neutron attenuation and resultant distribution of degradation under complex restraint conditions (Bruck et al 2019;Kambayashi et al 2020).…”