Computational chemo-thermo-mechanical coupling phase-field model for complex fracture induced by early-age shrinkage and hydration heat in cement-based materials

Abstract

In this paper, we present a new multi-physics computational framework that enables us to capture and investigate complex fracture behavior in cement-based materials at early-age. The present model consists of coupling the most important chemothermo-mechanical processes to describe temperature evolution, variation of hydration degree, and mechanical behavior. The changes of material properties are expressed as a function of the hydration degree, to capture the age effects. Fracture analysis of these processes is then accommodated by a versatile phase field model in the framework of smeared crack models, addressing the influence of cracks on hydration and thermal transfer. We additionally describe a stable and robust numerical algorithm, which aims to solve coupled problems by using a staggered scheme. The developed approach is applied to study the fracture phenomena for both homogeneous and heterogeneous concrete structures. Especially, in the second case, all microstructural heterogeneities of sand and cement matrix are explicitly accounted. Nucleation, initiation, and propagation of complex crack network are simulated in an efficient way demonstrating the potential of the proposed approach to assess the early-age defects in concrete structures and materials.

Experimental and numerical analysis of early age behavior in non-reinforced concrete

“…In the present work, the early-age behavior of the cement-based materials will be numerically investigated by using the multi-physics computational model based on the chemo-thermo-mechanical coupling in the phase field framework, whose basic concepts are reviewed in the following. For more details and practical implementation aspects, the interested reader can refer to [41,42,51].…”

“…8. Following the idea of our previous work [41,42], the state of the system is defined by four state variables, i.e., temperature T (x), displacement u(x), hydration degree α(x), and phase field d(x). Herein, the variable phase field d(x) is used to describe the damage/fracture level, d(x) = 0 for intact material and d(x) = 1 for fully cracked material.…”

“…A critical working condition is proposed to imply several critical zones with a high risk of cracking, which is similar to those introduced in [39,40]. The computational method based on the coupled multi-physics model in the phase field framework [41,42] is adopted in the numerical part. This model is based on the chemothermo-mechanical coupling scheme presented in [25,43], where the effects of both basic and transient thermal creeps are thus considered and integrated into the versatile phase field model in the framework of smeared crack models presented by Marigo and Francfort in [44], Miehe et al [45].…”

Heterogeneity effects on mixed‐mode I/II stress intensity factors and fracture path of laboratory asphalt mixtures in the shape of SCB specimen

“…[54][55][56][57][58][59][60][61][62][63] ) that can solve the crack problems faster than the finite element method can also be used for future fracture studies of heterogeneous asphalt mixtures. [54][55][56][57][58][59][60][61][62][63] ) that can solve the crack problems faster than the finite element method can also be used for future fracture studies of heterogeneous asphalt mixtures.…”

“…It is finally noted that although we used the finite element method for obtaining the stress intensity factors and path of heterogeneous asphalt mixtures, but other numerical methods and simulation mesh-free damage models XFEM and Extended Iso-Geometric Analysis (XIGA) techniques used in different papers (e.g. [54][55][56][57][58][59][60][61][62][63] ) that can solve the crack problems faster than the finite element method can also be used for future fracture studies of heterogeneous asphalt mixtures.…”