Investigation of the Influence of Overlays an‎d Patch Repairs on the Performance an‎d Durability of Reinforced Concrete Structures in Corrosive Marine Environments

3/21/2018 12:00:00 AM

Concrete structures in marine environments are affected by various destructive factors an‎d elements that cause damages to exacerbate over time an‎d eventually lead to deterioration of the concrete structures. According to the evidences an‎d reports of various failures, especially in tidal an‎d splash zones of marine concrete structures with severe corrosion of steel bars due to the penetration of chloride ion of seawater, it can be seen that repairs an‎d maintenance are inseparable parts of reinforced concrete structures in marine environments. Considering to the above, this research has tried to investigate the influence of patch repairs an‎d applying overlays for more adaptation an‎d protection on the performance an‎d durability of reinforced concrete structures in corrosive marine environments. In this research, by changing the physical an‎d electrochemical properties of repair’s materials an‎d overlays, the performance of the repairing system has been investigated. The various characteristics of repairing concretes an‎d base concretes have been eva​luated by using different tests such as compressive strength test, electrical resistance test, permeability test, water absorption test, rapid chloride penetration test (RCPT), rapid chloride migration test (RCMT) an‎d etc.. Also by conducting experiments such as potential of the corrosion an‎d the intensity of the corrosion current in modes of microcell an‎d macrocell an‎d etc. on the repairing system, the effects of repair’s materials an‎d overlays on corrosion processes in reinforced concrete structures have been eva​luated. For further achieve research purpose, seven slabs with different parts of the repairing system an‎d the same base concrete have been constructed. Three slabs have only been repaired locally an‎d three other slabs are also covered with various overlays in addition to the patch repairs. The results show that the electrical resistance of repairing concrete is a controlling parameter in the macrocell corrosion rate, however, this effect is not significant. If applying of overlay on the repairing system be able to limit the diffusion of oxygen an‎d moisture greatly, it can have a significant effect on the macrocell corrosion rate, while most overlays even increase the macrocell corrosion rate by increasing the electrolyte environment. Keywords: concrete durability, repairs, overlay, corrosion, marine structures.

دوام بتن , تعميرات , روكش , خوردگي , سازه‌هاي دريايي

Concrete Durability , Repairs , Overlay , Corrosion , Marine Structures

Mahyar Ghoroqi

Dr. Mohsen Saeedi - Dr. Parviz Ghoddousi