Factors Affecting the Bond Between Substrate-Overlay Material. A Review.

Repair is a common method for restoring deteriorated structures. A strong bond between the substrate-overlay is critical to concrete restorations. The interface layer between substrate-overlay effects the strength and durability of a composite system. This interface layer is influenced by the mechanical load and chemical properties of the composition of the substrate and repair material. Because of these interactions, the bond strength between the substrate- overlay concrete is critical. Factors influencing bond strength are surface roughness, micro fractures, compaction, curing, workability, and other environmental factors. Several tests are available to examine the bonding behaviour of substrate-overlay concrete. However, there is no specific way to determine bond strength. This paper outlines the various approaches and strategies by researchers to assess bond strength. Due to its simplicity, most researchers utilised slant shear test, split tensile test, and pull off test and avoided the mixed test method due to its complexity. According to literature, concrete repair is the best method, and higher strength concrete is used to produce better shear outcomes; conventional concrete is more cost-effective than higher strength concrete. [ABSTRACT FROM AUTHOR]