Effect of Fibers on the Onset of Strain Localization in HPFRCC Subjected to Plane Stress Loading

Abstract

The main objective of this study was to quantify effect of fibers on the onset of strain localization in elastic-plastic cementitious composites. To this end, multidirectional fibers were embedded into an elastic-plastic cementitious matrix and the resulting composite was described by several different types of nonassociated Drucker-Prager hardening plasticity models. Diagnostic strain localization analyses were conducted, thus providing strain and stress levels at the onset of strain localization, along with corresponding directions and modes of strain localization. Several actual uniaxial tension and compression tests on plain cementitious composites and on high-performance steel fiber-reinforced cementitious composites were investigated. Results showed that the onset of strain localization was slightly delayed in uniaxial tension and more significantly delayed in uniaxial compression tests on high-performance fiber-reinforced cementitious composites as compared to the plain mortar. Specifically, the diagnostic strain localization analysis appears to detect the inception of a fiber-induced distributed cracking in uniaxial tension tests, and the onset of a fiber-induced delay of a major crack localization in a uniaxial compression test.