Investigation of corrosion damage and repair system to strengthen the critical infrastructure

Abstract

This project provides a detailed study on the repair and strengthening of beams made up of concrete by Carbon Fiber Reinforced Polymer [CFRP] sheets. Mostly, structures fail due to the steel corrosion in the concrete. Corrosion remains primarily owing to the chloride ion intrusion in aggressive environment. The defected concrete will affect the strength of the structures. They can be treated with CFRP sheets so that the strength of the structure could be improved to withstand the design loads. The defects of the structures include-spalling of concrete, cracking, honey-combing etc., resulting in the reduction of strength. To strengthen the defected structure, we have implemented an idea of wrapping the corroded concrete with CFRP sheets. Reinforced concrete prisms will be casted and they will be grouped under four categories. First category of specimens will be kept as control specimens and another two groups of concrete specimen will be subjected to accelerated corrosion initiation test. The range of corrosion will be monitored through Half Cell Potential Mapping, after the crack formation on the surface of the specimens. Third group of prisms will be treated with CFRP sheets in one, two and three layers of the sheets. The last set of prisms will be treated with the CFRP sheets in one, two and three layers of the sheets without giving any chloride intrusion. Finally, the comparative study will be made on the strengths of all the three category specimens. We have selected M30 concrete grade and OPC53 grade of cement. All values are based upon IS 456:2000 and IS 10262:2009.