Related Experiment Video
Updated: Sep 7, 2025
05:38
Production and Analysis of Sporosarcina pasteurii Biocement Bricks Using Custom 3D-Printed Molds for Unconfined Compression Tests
Published on: March 7, 2025
442
Experimental Study on the Spatial-Temporal Failure Characteristics of Red Sandstone with a Cemented Structural
Ansen Gao1, Chengzhi Qi1,2,3, Renliang Shan1
1School of Mechanics and Civil Engineering, China University of Mining & Technology (Beijing), Beijing 100083, People's Republic of China.
ACS Omega
|June 20, 2022
Summary
Adding binders to rock discontinuities enhances shear strength and stability. Acoustic emission monitoring reveals distinct "quiet periods" and "jump increases" preceding brittle failure in red sandstone.
Area of Science:
- Geotechnical Engineering
- Rock Mechanics
- Materials Science
Background:
- Geological structural surfaces are critical in underground engineering, impacting structural stability.
- Understanding rock discontinuity failure is essential for safe and effective engineering designs.
Purpose of the Study:
- To investigate the spatial-temporal failure characteristics of discontinuities in red sandstone under uniaxial compression.
- To evaluate the effect of binders on the shear strength and stability of rock masses.
Main Methods:
- Uniaxial compression tests were performed on red sandstone specimens with cemented discontinuities.
- Acoustic emission (AE) ring counts and AE index (rise angle, average frequency) were monitored.
- Analysis of stress-strain curves and fracture patterns.
Main Results:
- Binder addition significantly improved the shear strength and stability of the rock mass.
- Red sandstone exhibited elastic-brittle failure with minimal plastic deformation.
- AE ring counts showed a distinct "quiet period" during elastic deformation, followed by a jump increase before brittle failure.
- AE index analysis indicated a progression from simple tensile/shear cracks to mixed mode fractures.
Conclusions:
- Cemented discontinuities enhance rock mass integrity and stability.
- AE monitoring effectively captures pre-failure warning signals in brittle rocks.
- Fracture development in red sandstone progresses from simple to complex modes and evolves spatially before failure.
More Related Videos
09:00Visualization of Failure and the Associated Grain-Scale Mechanical Behavior of Granular Soils under Shear using Synchrotron X-Ray Micro-Tomography
Published on: September 29, 2019
13.5K
06:55Kinematic History of a Salient-recess Junction Explored through a Combined Approach of Field Data and Analog Sandbox Modeling
Published on: August 5, 2016
8.3K
Related Concept Videos
01:23Behavior of Concrete Under Compressive Load
267
Concrete exhibits specific behaviors under different compressive loads. Understanding this is crucial for understanding its structural integrity. When concrete undergoes uniaxial compression, it tends to develop cracks that run parallel to the direction of the force. These parallel cracks stem from localized tensile stresses that occur perpendicular to the compression direction. Additionally, angled cracks may appear due to the formation of shear planes.
As the concrete specimen fractures under...
As the concrete specimen fractures under...
267
01:20Strength of Cement
214
Strength tests for cement are not performed directly on neat cement paste due to difficulty in obtaining consistent, reliable specimens. Instead, cement is typically tested in the form of cement-sand mortar.
For compressive strength tests, ASTM C 109-05 standards prescribe a cement-sand mix ratio of 1:2.75 and a water/cement ratio of 0.485 for making 2-inch cubes. These cubes are mixed, cast, and cured in saturated lime water at 23°C until testing. Flexural strength testing, outlined in...
For compressive strength tests, ASTM C 109-05 standards prescribe a cement-sand mix ratio of 1:2.75 and a water/cement ratio of 0.485 for making 2-inch cubes. These cubes are mixed, cast, and cured in saturated lime water at 23°C until testing. Flexural strength testing, outlined in...
214
01:20Microcracking in Concrete
204
Microcracking in concrete refers to the tiny cracks that can form within the material even before any external load is applied. These microcracks typically occur at the interface between the coarse aggregate and the hydrated cement paste, often as a result of differential volume changes prompted by variations in stress-strain behavior, as well as thermal and moisture movement. Initially, these microcracks remain stable and do not grow substantially until the concrete is stressed to about 30...
204
01:22Fatigue Strength of Concrete
282
Fatigue, in the context of materials science and engineering, refers to the weakening or failure of a material caused by repeatedly applied loads, even if these loads are below the strength limit of the material. Fatigue strength in concrete is a critical property that influences its durability and longevity. Concrete can fail in two ways due to fatigue. Static fatigue or creep rupture occurs under a constant load or one that increases slowly. The other failure mode is due to cyclical or...
282
01:16Tensile Strength Considerations of Concrete
194
Considering the tensile strength of concrete involves recognizing that the theoretical strength of cement paste can be up to a thousand times higher than what is observed in practical applications. This significant discrepancy is largely attributed to the presence of microscopic cracks within the concrete. These cracks tend to amplify stress at their tips when a load is applied, a phenomenon explained by Griffith's theory of brittle fracture.
The dimensions and shape of a concrete specimen...
The dimensions and shape of a concrete specimen...
194
01:22Creep in Concrete
440
Creep refers to the time-dependent increase in strain under a sustained load, excluding other time-dependent deformations associated with shrinkage, swelling, and thermal expansion in concrete. The primary mechanism behind creep involves the loss of physically adsorbed water from the calcium silicate hydrate within the hydrated cement paste. This process is further exacerbated by concrete's non-linear stress-strain relationship, microcrack development in the interfacial transition zone, and...
440