Self-Repair Epoxy Modified Mortar for Rehabilitation and Strengthening Applications Using FRP
M. M. Reda Taha
Appears on pages(s):
concrete repair; epoxy-modified polymers; epoxy mortar; externally bonded fiber reinforced polymers; fiber reinforced polymer (FRP); rehabilitation; self-repair; self-repair epoxy mortar; strengthening
Strengthening and rehabilitation of reinforced concrete structures using externally bonded Fibre Reinforced Polymers (FRP) strips has become a well-established technique with a large research database. Epoxy-modified mortar (EMM) has been used in the industry for more than three decades for various strengthening and rehabilitation purposes. Epoxy modified mortar without a hardener has recently been investigated. The new EMM without a hardener includes polymerlcement ratios as low as 20 percent compared to the 40-60 percent that is usually required to provide suitable mechanical properties of conventional EMM. The new EMM utilizes the cement hydrates to polymerize the epoxy resin in the cement matrix in the absence of a hardener through ring-opening polymerization. The use of ring-opening polymerization provides EMM (without a hardener) with an interesting ability to grow through any developed crack and to repair itself, thus showing enhanced fracture toughness with age. The new self-repair epoxy mortar (SREM) has shown better mechanical performance than the conventional EMM with the same polymer/cement ratio. The objective of this work is to discuss the potential use of SREM to bond FRP laminates to existing concrete substrates in rehabilitation and strengthening applications. A multi-phase research programme examining the different strength, fracture and durability criteria of the SREM-FRP composite is proposed here. Fracture mechanics principles in conjunction with microstmctural investigations will explain and maximize the material ability to self-repair.