Fracture properties of ternary blended fiber reinforced self-compacting concrete-A plastic viscosity approach

Abstract

With the demand in the usage of Self-Compacting Concrete (SCC) there is a need to look into an alternate procedure of mix design to address the present practical issues. The existing standards of SCC mix design either underestimates or overestimates the materials used for the production of concrete which reduces the workability, durability and increases the cost. In the present study a mix design procedure which is based on the plastic viscosity of paste and target compressive strength of the SCC mix is being developed using a micromechanical procedure. Cement Replacement Materials like Slag and Fly ash are used for the present study in binary and ternary mix compositions. To address the issue of scarcity of river sand in India, Crushed Rock Fine is used a fine aggregate for the proposed mix design. To enhance the mechanical characteristics of SCC mixes, influence of varying fiber fraction is also studied for the Ternary SCC mixes. The volume fraction of fibers and aspect ratio of fibers are entered as an input into the programming tool to obtain combinations of SCC mixtures. Hooked end steel fibers with volume ranging from 0.1% to 0.5% are chosen for the experimental investigation. Results indicated that the compressive, split tensile and flexural strengths increased with the increase in fiber volume fraction but the fresh properties slump flow, T500 and J-ring spread, V-funnel and L-box decreased. Further, the study is extended in evaluating the fracture energy of Ternary SCC mixes with and without fibers. Fracture energy increased with the increase in fiber volume and post-peak responses are captured more accurately with the presence of fibers. The evaluated fracture energy will be useful for the analysis of cracked concrete structural components.