Related Experiment Video
Updated: May 12, 2025
09:12
A Method for Studying the Temperature Dependence of Dynamic Fracture and Fragmentation
Published on: June 28, 2015
8.5K
Fracture Analysis of Concrete Structures: Prediction Based on Boundary Effect Model
Gang Han1, Xiangyu Han2, Yi Ji3
1Department of Mechanical Engineering, University of Western Australia, Perth, WA 6009, Australia.
Materials (Basel, Switzerland)
|May 7, 2025
Summary
The Boundary Effect Model (BEM) effectively links small concrete sample tests to large structure failures. This fracture analysis tool accurately predicts concrete behavior and size effects, incorporating aggregate influence and statistical analysis for reliable results.
Area of Science:
- Civil Engineering
- Materials Science
- Structural Analysis
Background:
- Accurate fracture analysis of concrete structures requires models linking small-scale test results to large-scale structural failures.
- Existing models often lack the ability to handle various sample types or incorporate critical factors like aggregate size.
- The Boundary Effect Model (BEM) has evolved over 20 years to address these limitations in concrete fracture analysis.
Purpose of the Study:
- To evaluate the linear Boundary Effect Model (BEM) for its ability to predict concrete fracture behavior and size effects.
- To demonstrate BEM's capability in linking small concrete sample test results to the failure of large structures.
- To investigate the influence of aggregate size on concrete fracture and its incorporation into the BEM.
Main Methods:
- Utilized a comprehensive dataset of concrete fracture results from literature and new experimental data from 138 three-point bending (3-P-B) tests.
- Analyzed specimens with varying notch depths (un-notched, shallow, and deep) and inconsistent dimensions.
- Integrated statistical analyses into BEM to account for experimental scatter and improve predictive reliability.
Main Results:
- The linear BEM accurately models the fracture process zone (FPZ) and quasi-brittle fracture behavior of concrete.
- BEM successfully links small sample behavior to large structure performance with reliable predictions.
- The model effectively incorporates the influence of average aggregate size (dav) on fracture, a feature lacking in many other models.
- Statistical integration within BEM enhanced its reliability in predicting maximum fracture loads.
Conclusions:
- The linear BEM is a simple, reliable, and accurate tool for concrete fracture analysis across various scales.
- BEM's ability to incorporate aggregate size and statistical variations makes it a valuable predictive model for engineers.
- The model's effectiveness is confirmed for predicting fracture behavior in both notched and un-notched concrete specimens and structures.
Related Concept Videos
01:20Microcracking in Concrete
87
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...
87
01:23Behavior of Concrete Under Compressive Load
123
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...
123
01:24Stress-Strain Diagram - Brittle Materials
969
Brittle materials, including glass, cast iron, and stone, exhibit unique characteristics. They fracture without considerable change in their elongation rate, indicating that their breaking and ultimate strength are equivalent. Such materials also show lower strain levels at the point of rupture. The failure in brittle materials predominantly results from normal stresses, as evidenced by the rupture created along a surface perpendicular to the applied load. These materials do not display...
969
01:16Tensile Strength Considerations of Concrete
96
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...
96
01:28Types of Non-structural Cracks in Concrete
100
Non-structural cracks are primarily of three types: plastic, early-age thermal, and drying shrinkage cracks. Plastic cracks are further classified into plastic shrinkage cracks and plastic settlement cracks.
Plastic shrinkage cracks typically form within hours after the concrete is poured. The concrete's surface dries faster than the bottom, creating tensile stress that the still-plastic concrete cannot withstand, leading to diagonal or randomly patterned cracks on the concrete surface.
Plastic shrinkage cracks typically form within hours after the concrete is poured. The concrete's surface dries faster than the bottom, creating tensile stress that the still-plastic concrete cannot withstand, leading to diagonal or randomly patterned cracks on the concrete surface.
100
01:22Creep in Concrete
108
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...
108