Analysis of strength property and pore characteristics of Taihang limestone using X-ray computed tomography at high temperatures

Abstract

Rising temperature will cause the changes of pore characteristics and strength property in rock. This research takes the limestone produced in Taihang Mountains as the research object, and performs high-temperature treatment within 25–1000 °C. The high-resolution X-ray computed tomography (CT) scanning test method is used to visually reconstruct the three-dimensional image of the sample, and obtain the spatial distribution status of the mesoscopic parameters of the bones, pores/cracks, etc. The results show that when the temperature exceeded 700 °C, the samples appeared milky white in appearance and as the temperature increased, the color gradually turned white, macroscopic cracks began to appear on the surface, while the meso-pores connected rapidly, reflecting a typical progressive destruction process from inside to outside. The change law of volume porosity with temperature has a consistent trend with that of the apparent morphology of the sample. Similarly, the mechanical test results suggest that 700 °C is also the turning temperature for strength deterioration and brittle-plastic transformation of sample. Based on the results of high-temperature test, CT test and mechanical test, there are enough evidences to show that, for the limestone sample, 700 °C is probably to be the mutation temperature of physical–mechanical behavior.

Porosity of the porous carbonate rocks in the Jingfengqiao–Baidiao area based on finite automata

“…Compared with using CT to build a three-dimensional pore model of carbonate rocks, the cost of this research method is lower. Compared with the research results for the Taihang area [ 24 ], the research method used in this study has a lower cost and a shorter research period. Compared with the study of rock pores using only image processing technology [ 40 , 41 , 43 ], the research results obtained using the TCRM to verify the image finite automata used in this study are easier for the engineering department to accept and use.…”

“…Their results show that the image acquisition equipment plays a very important role in carbonate image analysis. Liu et al [ 24 ] studied the analysis of the strength property and pore characteristics of the Taihang limestone using X-ray CT at high temperatures. Their results show that image analysis technology plays a very important role in carbonate pore analysis.…”

Persistent Homology as a Heterogeneity Metric for Predicting Pore Size Change in Dissolving Carbonates

“…This highlights an inherent limitation of using XCT data to characterize the pore networks of carbonates. Still, XCT scans at 15 μm or coarser resolution have been effective for observing and predicting pore network properties in carbonates in many prior studies (e.g., S. Liu & Huang, 2021; Siddiqui et al., 2006; Sukop et al., 2013; Yoo et al., 2021). With this known limitation in mind, this study focuses primarily on the largest pores in these samples, which could be characterized with the greatest confidence.…”

Deformation evolves from shear to extensile in rocks due to energy optimization

“…Consequently, there is a fundamental gap in our understanding of how fractures that may nucleate as extensile fractures, develop and coalesce into system-scale fracture networks that are aligned along the orientations predicted by the Coulomb criterion. Observations from in situ X-ray tomography triaxial compression experiments Advanced experiments with in situ X-ray tomography have provided unparalleled insights into the factors that control fracture network development [6,[30][31]. Recent work has examined the evolving accumulation and partitioning of the local strain tensors in triaxial compression experiments on a wide range of rocks [32].…”