On Size Effect in Tension of SFRC Thin Plates

More than 48 SFRC thin plates characterized by a central notch (notch ratio = 0.2), a highstrength matrix (fc = 75 MPa) and two different types of steel fibers, were tested in tension. Three sizes were considered (1 : 2.5 : 6.25). They were subjected to uniaxial tension (rotating-end platens), eccentric tension, and 4-point bending. Each test was repeated three times. The material characterization was performed by means of direct tension tests (notched specimens) and 4-point bending tests (unnotched specimens); three unnotched large slabs were also tested according to a 4-point bending test procedure. The tests highlight both the deterministic and the statistical size-effect. The results show a significant difference between uniaxial tension and bending with reference to post-cracking behavior. By adopting a plane-section kinematic model and a constitutive law identified on the basis of unnotched 4-point bending procedure, the whole set of tests was reproduced to validate a linear softening constitutive model and to discuss the application limits for design.