Abstract;
The quality of a bonded concrete overlay relies on the interface bonding, influenced by factors like the presence and amount of fibers in the new concrete, moisture status, and surface roughness of the existing concrete. This study presents an empirical investigation to evaluate the interfacial bond strength behavior between Steel Fibre Reinforced Concrete (SFRC) and Plain Concrete (PC) substrates. The main goal is to quantify the shear bond strength at the interface while considering the influence of fiber presence and content in the new concrete, moisture levels, and the surface roughness of the existing concrete.
Incorporating steel wire fibers as reinforcement in the FRC, this research analyzes their impact on bonding strength. To gain deeper insight into the bonding mechanism, square prism specimens with varied moisture conditions (air dry, saturated surface dry – SSD, and wet) are fabricated. These specimens incorporate five different fiber volume fractions: 0%, 0.5%, 1.0%, 1.5%, and 2.0%, as overlays on three distinct surface textures – As Cast surface, Grooved surface, and Wire brush surface.
Results indicate that, across all moisture conditions (SSD, wet, and air dry), the bond strength of FRC samples surpasses that of the control samples regardless of the surface texture. Notably, the bond strength of FRC with 1% fiber volume displays significant enhancement. This improvement is particularly prominent on grooved surface textures under SSD moisture conditions of the existing concrete surface. The highest interfacial bond strength of 15.19 N/mm² is achieved by FRC containing 1.0% steel fibers. Notably, the bond strength of FRC consistently outperforms that of the control specimens.
In accordance with the ACI Concrete Repair Guideline, all roughened surface textures examined in this research fulfill the specified minimum bond strength requirement. Taking into account the findings and evaluations from this study, it is recommended to utilize 1% steel FRC, grooved surface treatment, and SSD surface conditions when aiming to produce retrofitted or repaired concretes, with the primary objective of achieving improved interfacial shear bond strength.
Investigating Interfacial Bond Strength Characteristics Between Steel Fiber Reinforced Concrete and Plain Concrete Substrate. GET MORE, ACTUARIAL SCIENCE PROJECT TOPICS AND MATERIALS
