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arXiv · 2311.07785

Fracture of bio-cemented sands

C. Konstantinou·E. Martínez-Pañeda·G. Biscontin·N. A. Fleck
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Abstract

Bio-chemical reactions enable the production of biomimetic materials such as sandstones. In the present study, microbiologically-induced calcium carbonate precipitation (MICP) is used to manufacture laboratory-scale specimens for fracture toughness measurement. The mode I and mixed-mode fracture toughnesses are measured as a function of cementation, and are correlated with strength, permeability and porosity. A micromechanical model is developed to predict the dependence of mode I fracture toughness upon the degree of cementation. In addition, the role of the crack tip $T$-stress in dictating kink angle and toughness is determined for mixed mode loading. At a sufficiently low degree of cementation, the zone of microcracking in the vicinity of the crack tip is sufficiently large for a crack tip $K$-field to cease to exist and for crack kinking theory to not apply. The interplay between cementation and fracture properties of sedimentary rocks is explained; this understanding underpins a wide range of rock fracture phenomena including hydraulic fracture.

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C. Konstantinou, E. Martínez-Pañeda, G. Biscontin, N. A. Fleck. 2023-11-13. Fracture of bio-cemented sands. https://arxiv.org/abs/2311.07785

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