Effect of water content on the failure pattern and acoustic emission characteristics of red sandstone

Zhao, Kui; Yang, Diansen; Zeng, Peng; Huang, Zhen; Wu, Wenkai; Li, Bo; Tian-ye, Teng

doi:10.1016/j.ijrmms.2021.104709

Cited by 92 publications

(27 citation statements)

References 59 publications

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“…After touching by hand, there was a sandy feel and the phenomenon of small particles falling off. This was because water molecules in the pores and cracks of gray brick had the effect of softening the mineral skeleton, so the cement between particles underwent dissolution and dissolution reactions [ 25 , 26 , 27 ]. At the same time, minerals such as albite and anorthite in gray brick reacted with water to produce various secondary minerals, resulting in interparticle cements which gradually became detached [ 28 ].…”

Section: Resultsmentioning

confidence: 99%

Study on Deterioration of Gray Brick with Different Moisture Contents under Freeze–Thaw Environment

Yue

Zhao

et al. 2022

Materials

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Generally, brick buildings are in the open-air environment year round, and damage to them is aggravated by the effect of repeated freezing and thawing cycles. In order to determine freeze–thaw damage and deterioration mechanism, the initial moisture content of gray brick specimens was set as 20%, 40%, 60%, 80%, 100%. The effects of moisture content and the number of freeze–thaw cycles on the quality, mechanical properties and microstructure of gray brick were investigated by uniaxial compression tests and scanning electron microscopy (SEM) tests. Numerical simulations were applied to model the freezing and thawing process. The results showed that: as the number of freeze–thaw cycles increased, the mass loss rate and peak strength reduction rate of gray brick both increased. The initial moisture content had a greater impact on damage to gray brick due to freeze–thaw; ω = 80% was defined as the limit moisture content of gray brick. Under the repeated action of freeze–thaw cycles, the areas affected by thermal stress were mainly concentrated in the center of the outer surface and the center of the side of gray bricks. The maximum thermal stress after 55 freeze–thaw cycles was 1.522 × 10−2 MPa. This research results provide a theoretical basis for the prevention and protection of frost damage of brick buildings in a freeze–thaw environment.

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Section: Resultsmentioning

confidence: 99%

Study on Deterioration of Gray Brick with Different Moisture Contents under Freeze–Thaw Environment

Yue

Zhao

et al. 2022

Materials

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“…Castro-Filgueira (Castro-Filgueira et al, 2017), a large number of trial calculations were carried out to determine the initial parameters of the model micromechanical parameters, as shown in Table 1. According to the literature (Zhao et al, 2021), it can be known that the water content influences the normal, tangential bond strength and bond strength ratio parameters of the rock. Combined with the data in the literature (He, 2021;Jing et al, 2021;Liu et al, 2021), the functions of rock normal, tangential bond strength, bond strength ratio, and water content are obtained.…”

Section: Macroscopic Evolution Law Of Mudstone Under the Action Of Wa...mentioning

confidence: 99%

Instability and failure characteristics of surrounding rock of water drenching roadway in thick coal seam

Jia

Fan

et al. 2022

Front. Earth Sci.

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Aiming at the water drenching problem in the roof of transport roadway 2,606 of the Zhangcun coal mine, the instability and failure law of the drenching roadway was studied by borehole peephole, soaking water softening test and numerical simulation in this study. It is found that the relation between compressive strength, elastic modulus, tensile strength and moisture content is a negative exponential function. Subsequently, the Fish language was used to embed the functional relationship between mechanical parameters of surrounding rock in the roadway and moisture content into Flac3D software to simulate the failure law of surrounding rock under different moisture contents. The influence of moisture content on the surrounding rock is ordered as roof > two sides > floor. Through the comparison between borehole peeping and plastic zone, the roof water content is obtained by inversion. The results provide a reference basis for the selection of the surrounding rock support method for drenching roadway in thick coal seam.

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“…When the rock is subjected to load, microcracks gradually occur, then expand and merge, accompanied by the release of elastic strain energy, namely acoustic emission (AE) 33,34 . The basic parameters of acoustic emission ringing count rate, accumulative ringing count, energy rate and accumulative energy are often used to analyze the evolution process of rock damage and fracture [35][36][37] . Through the displacement-time curve, the evolution process of compression-shear fracture of specimens with different brittleness degree is divided into three stages: compaction stage and elastic deformation stage, constant deformation stage and accelerated deformation stage.…”

Section: Evolution Stage Division Of Multivariate Parametersmentioning

confidence: 99%

Experimental study on compression-shear fracture evolution process of locked segment of rock-like based on multivariate parameters

Jiang

Wan

Huang

et al. 2022

Preprint

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Locked segment of rock-like material specimens with different brittleness index were prepared by combining materials in different ratios. Compression-shear tests of rock-like material specimens with different brittleness degree were carried out by acoustic emission and Laser Doppler Vibrometer measurement. The fracture evolution process of the specimen was divided into three stages through the displacement-time curve: compaction stage and elastic deformation stage, constant deformation stage and accelerated deformation stage. The natural frequency responded obviously at the boundary point of the constant deformation stage and accelerated deformation stage, the point of natural frequency steeply dropped corresponds to the starting point of constant deformation stage, which is defined as the damage point. The point of substantial increase in the natural frequency corresponds to the starting point of accelerated deformation stage, which is defined as expansion point. There were obvious critical instability information before the failure of specimens: The natural frequency showed rise, steep drop and stable jitter; The ringing count rate and energy rate increased near the critical instability point; The b-value continued to decrease at a low level before the peak strength. Tensile failure was the main failure mode of the three specimens with different brittleness degree, the tensile failure degree increased with the increase of brittleness degree. The energy released by the specimen at failure moment increased with the increase of brittleness degree, and the b-value decreased with the increase of brittleness degree. The degree of brittleness is one of the important indexes to study the locked segment.

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Effect of water content on the failure pattern and acoustic emission characteristics of red sandstone

Cited by 92 publications

References 59 publications

Study on Deterioration of Gray Brick with Different Moisture Contents under Freeze–Thaw Environment

Study on Deterioration of Gray Brick with Different Moisture Contents under Freeze–Thaw Environment

Instability and failure characteristics of surrounding rock of water drenching roadway in thick coal seam

Experimental study on compression-shear fracture evolution process of locked segment of rock-like based on multivariate parameters

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