Combined effects of recycled crumb rubber and silica fume on mechanical properties and mode I fracture toughness of self‐compacting concrete

Abstract

AbstractThe effects of recycled crumb rubber up to 25% replacement of fine and coarse aggregates in two discreet gradations combined with 0% to 25% substitution of cement by silica fume were studied on the mechanical and fracture properties of self‐compacting concrete (SCC). For acquiring a diverse means of comparison, toughness index and energy absorbency of different mixtures were tested, and stress intensity factors of different mixtures were obtained. Additionally, statistical analyses were conducted to verify the validity of the results, and also, regression analyses were conducted to predict the values of flexural strength, toughness index, energy absorption, and fracture toughness of SCC mixtures. The results show that the addition of crumb rubber reduces the modulus of rupture, energy absorbency, and fracture toughness values, but the incorporation of silica fume can compensate for the losses. Conversely, there was a large rise in toughness index when adding crumb rubber.