序I
Preface I
Preface II
Summary
1 Introduction
1.1 Overview
1.2 Fracture Experiments of Tnree Gorges Dam Concrete
1.2.1 Specimens
1.2.2 Materials and mix proportions
1.2.3 Test program
1.2.4 Three-point bending notched beam (TPB) tests
1.2.5 Wedge splitting (WS) test
1.2.6 Direct tension (DT) tests and fundamental mechanical performance tests
2 State-of-the-art Review on Concrete Softening Curve
2.1 Introduction
2.2 Determination Approach of the Tensile Softening Relationships (a-w curves)
of Concrete
2.2.1 Direct tension test method
2.2.2 J-Integral method
2.2.3 Inverse analysis method
2.3 Shape of Softening Curve of Concrete
2.3.1 Linear shape softening curve of concrete
2.3.2 Linear softening curve of concrete
2.4 Conclusions
References
3 Two Methods for Determining Softening Relationships of Dam Concrete andWet-screening
Concrete
3.1 Introduction
3.2 Experiments
3.2.1 Material, mix and specimens preparation
3.2.2 Fracture tests
3.3 Softening Relationships of Dam Concrete and Wet-screened Concrete
Determined by the Direct Tension Tests
3.3.1 Stress-deformation (a-d) curves
3.3.2 Direct tension method for identifying a-w curve
3.3.3 Results of direct tension method
3.4 Softening Relationships Determined by the Inverse Analysis Method
3.4.1 Cracking strength
3.4.2 Inverse analysis method based on the cracking strength criterion
3.4.3 Results of inverse analysis method
3.5 Comparison of Softening Relationships of Dam Concrete and Wet-screening
Concrete
3.5.1 Comparison of Softening Relationship of Dam Concrete and Wet-
Screening Concrete Determined by Direct Tension Method and Inverse
Analysis Method
3.5.2 Comparison of Fracture Energy of Dam Concrete and Wet-Screening
Concrete Determined by WOF Method and TSD Method
3.6 Conclusions
References
4 Prediction of the Tension Softening Curve of Dam Concrete Based on BP Neural
