Investigation of tensile fracture of rubberized self-compacting concrete by acoustic emission and digital image correlation

Damage and failure of rubberized self-compacting concrete (RSCC) under uniaxial tension are investigated by acoustic emission (AE) and digital image correlation (DIC) techniques. Four RSCC mixtures containing fine rubber particles with 0%, 5%, 10%, and 15% volume fractions are tested. The effect of rubber content on the macroscopic mechanical behavior, the AE parameters, the strain fields, and the damage developments are analyzed. It is demonstrated that the combined use of AE parameters and DIC strain maps provides an accurate estimation of different stages of damage evolution and that the crack propagation measured by DIC correlates strongly with all AE parameters. Modes of cracking are determined by analyses of average frequency (AF) versus rise time-amplitude (RA) values to demonstrate an additional feature of AE, which can be used for explanations of different behaviors under different loading conditions. It is shown that the substitution of fine aggregates with fine rubber particles leads to a reduction of stiffness, strength, and fracture toughness when the material experiences uniaxial tension. This has to be considered in the design of structures with RSCC.