Saudi Journal of Civil Engineering (SJCE)
Volume-5 | Issue-07 | 222-235
Original Research Article
Friction Force Reduction of Corroded and Exudates Coated Reinforcing Steel Exposed to Severe Media
Gregory C. Ezeokpube, Charles Kennedy, Michael Ebie Onyia
Published : Aug. 30, 2021
Abstract
The performance of reinforced concrete structures, as in other composite members, depends on the bond between the steel and the concrete which ensures that load is transferred safely between the two materials. The research involved the direct application of environmentally and eco-friendly extracted exudates/resins used to control the effect of corrosion attacks by coating steel with varying thicknesses, embedded in concrete structures and immersed in sodium chloride (NaCl) solution for corrosion accelerated process. Laboratory experimental samples reflected the acid level of sea salt concentration in reinforced concrete cubes. The data for comparison of maximum obtained values are failure bond load are corroded -41.594% against 78.166% and 80.194% controlled and coated, bond strength is -34.227% against 73.201% and 69.943% and maximum slip are -42.731% against 102.034% and 113. The summarized computed and compared results of failure bond load, bond strength and maximum slip of the controlled, corroded and coated samples showed that the effect of sodium chloride as detailed in the "2.2 Experimental procedures" has adversely affected the mechanical properties of reinforcing steel of uncoated (corroded) samples which has resulted to poor performances, low load at failure state, less bond strength and slippage. The coated samples exhibited the potential of sustaining the negative effect of corrosion on reinforcing steel and by forming good contact and interlock between concrete and reinforcing steel by reducing the stress existing in the concrete surroundings. Results showed that the diameter of corroded reinforcement decreases by a maximum of -0.771% and the coated increases by 0.831%, for the cross-sectional area corroded has a maximum reduction value of -13.163% and the coated increases by 20.74%, the weight loss and increase in corroded is -22.887 % decreased (loss) and coated increased by 34.929% (gain). Regarding the mechanical properties of reinforcing steel, the effect of corrosion on reinforcing steel shows a decrease in the cross section of the rebar diameter compared to the nominal diameter before testing, weight reduction is also observed, an increase in the cross-sectional area, an increase in the diameter and minute increase in weight resulting from coating material as compared with the nominal reinforcement, which is due to differences in the thickness of the layered materials. It can be concluded that the exudate / resin studied has shown effective inhibiting properties against corrosion attack and can be used as a corrosion inhibitor