Uniaxial tension test for the determination of fracture parameters of concrete: state of the art

An overview is given of methods to determine the strength and fracture energy of concrete subjected to uniaxial tension. The test method is often erroneously––and persistently––referred to as the `direct tension testʹ. After a brief review of historical, mostly indirect methods, the paper focuses on more recent servo-controlled testing techniques. Assessment of effects like secondary bending, and rotation and/or translations of the loading platens, as well as size/scale effects and environmental effects on fracture seem important for a proper definition of tensile strength and fracture energy. Implications for modeling are debated. The methods can be transferred directly to studies of other quasi-brittle geo-materials like natural rocks, clay and ice, fired clay bricks, plaster and the like.