Abstract
In this paper, various methods for determining the toughness of steel fiber reinforced concrete (SFRC) are compared and evaluated using five criteria. The ASTM C1018-85 method mostly conforms to these criteria and, hence, is accepted as the foundation for China's standard test method of compressive toughness of SFRC. It is proposed that the critical-load point replace the first-crack point in defining the compressive toughness index based on an analysis of the onset and propagation of cracks in concrete under uniaxial compressive loading. The transient coefficient for load-carrying capacity is also given to indicate the variational characteristic of toughness. Experiments were carried out to verify the validity of the recommended index.