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Shear Energy Evolution and Fracture Behavior of Rock-Concrete Interfaces Under Different Stress-Level Conditions
Taoying Liu1, Min Tang1, Ping Cao1
1School of Resources & Safety Engineering, Central South University, Changsha 410083, China.
Materials (Basel, Switzerland)
|February 26, 2025
Summary
Increasing normal stress enhances sandstone-concrete interface strength by limiting micro-cracks and altering fracture modes. Higher stress improves energy storage and bearing capacity, with shear fractures dominating failure.
Area of Science:
- Geotechnical Engineering
- Materials Science
- Rock Mechanics
Background:
- Understanding rock-concrete interface behavior is crucial for infrastructure stability.
- Direct shear tests are vital for assessing interface strength and failure mechanisms.
Purpose of the Study:
- Investigate shear energy evolution and fracture behavior of sandstone-concrete interfaces under varying normal stresses.
- Quantify the impact of normal stress on shear strength and failure modes.
Main Methods:
- Conducted indoor direct shear tests on sandstone-concrete samples.
- Utilized acoustic emission (AE) and digital image correlation (DIC) techniques.
- Analyzed energy evolution (input, elastic, dissipated) and crack propagation patterns.
Main Results:
- Shear strength increased by 12.3-34.34% with rising normal stress.
- Normal stress restricted micro-crack coalescence and enhanced bearing capacity.
- AE and RA-AF analyses revealed a three-stage crack propagation and a shift towards shear fracture dominance.
Conclusions:
- Normal stress significantly improves sandstone-concrete interface shear strength and bearing capacity.
- Energy evolution patterns are consistent, but energy storage capacity increases with normal stress.
- Tensile wing cracks initiate failure, with shear fractures becoming more prevalent under higher normal stresses, especially on serrated interfaces.
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