Bond Performance of Concrete-To-HPC Interface for Different Surface Profiles Using Slant and Bi-Surface Shear Test

Abstract

Concrete structures are usually used in all construction fields. However, it is exposed to cracking and corrosion over time, especially when exposed to harsh conditions. This requires continuous repairs to ensure the structure’s functionality, durability, and safety. High-Performance Concrete (HPC), is one of the best concretes which used for repairing. This study was conducted to assess the influence of different surfaces of normal concrete (NC) and the use of bonding agent on the adhesion strength of High-Performance Concrete (HPC). The trial work was based on a set of composite samples, where the substrate was made of (NC) and the cover layer was made of (HPC). A commercial bonding material (epoxy resin) was used to bond the NC with a smooth surface to the HPC layers of concrete. Three substrate surfaces were considered: a smooth surface, a smooth surface coated with epoxy, and a rough surface. The adhesion performance was evaluated through two tests: the slant bond test and the bi-surface test after 28 days of curing. DIC (digital technique correlation) was applied to notice the process of failure in specimens. The preliminary results showed that the bonding between the two types of concrete was very good. The best bonding strength was NC with the rough surface bonded by HPC, followed by the smooth surface-epoxy, and then the smooth surface by mean (5.83, 4.73, 3.92) respectively for the bi-surface test, and by mean (6.89, 5.68, 4.71) respectively for the slant bond test. However, further studies are needed to test more types of surfaces and different conditions