1. Why can LEFM not be applied to concrete directly?
2. Describe the special characteristics of a concrete fracture process?
3. What is the two-parameters model?
1. Describe the size effect law.
2. What is the main difference between the fictitious model and the size effect law?
1. Show how to construct R-curve for concrete.
2. Show how to determine the necessary parameters for a two-parameters model, the size effect law, and the R-curve approach.