Book Description

Because of the nature of the hydraulic structures over which the Army Corps of Engineers has responsibility, there are frequent requirements to repair spalled or eroded concrete that is underwater, close to the waterline, or in areas from which it is difficult to divert flow or dry the concrete. This investigation evaluated the effectiveness of commercially available products in repair of concrete with wet surfaces. Slant-shear bond and compressive strength tests were conducted on each of the 22 materials recommended for repair of spalls in wet concrete. Based on the results of these screening tests, eight materials were selected for additional laboratory tests including: a) bonding capacity in direct tension; b) bonding capacity under flexural stress; c)resistance to abrasion; d) resistance to cycles of freezing and thawing; e) impact resistance; and f) thermal capability with concrete. Test results and material costs were used in developing a rating system to compare the relative performance of the various materials. Overall performance ratings indicate two materials, an epoxy and a cement-based product, were nearly equal in outperforming the other products tested. Which of these two materials is to be specified for a given repair will likely depend on the specific project requirements and critical material properties. Concrete repair. (edc).