Bond Strength of Fly Ash and Silica Fume Blended Concrete Mixes

Abstract

Abstract The bond between steel reinforcing bars and concrete is critical to reinforced concrete's successful functioning as a composite element. Dysfunction of this bond can result in catastrophic building and infrastructure failure. Concrete strength and reinforcement characteristics such as embedment length, ribs, diameter, and confinement in concrete are the factors that influence the steel-concrete bond. This work represents the bond strength of ribbed reinforcing bars in Fly ash (FA), and Silica fume (SF) blended concrete mixes. Binary and ternary blended FA and SF concrete mixes with different combinations of percentage replacements of cement by FA (20%, 30%, 40%) and SF (5%, 7.5%, 10%) were adopted. Different bar diameters (12 mm and 16 mm) and embedment length at full depth of specimen were used to assess the bond strength. A direct pull-out test by IS 2770-1 was used to determine bond strength. The bond strength values exhibited by blended concrete mixes were compared to those of conventional concrete. The findings from the bond strength analysis indicate that incorporating FA and SF in concrete mixtures can be a viable approach for developing environmentally sustainable concrete. The micro structural features obtained in the current study provide a rationale for the performance of these blends.