Structural health monitoring of RC beams at lap splices of tensile steel bars using bonded piezoelectric transducers

Abstract

Lap splices in steel bars of Reinforced Concrete (RC) structures must newlinebe continuously monitored using Structural Health Monitoring (SHM) newlinetechniques. Among various forms of splicing of reinforcement including lap newlinesplicing, mechanical splicing and welded splicing, lap type of splicing was newlineproven to be effective in various applications and has been adopted invariably in newlineall type of RC elements. Lap splices are employed in members that require long newlinecontinuous reinforcement. The bond between the reinforcement, such as steel newlinebar, and the concrete affects the structural performance of concrete newlineconstructions. Cracking, crack severity, deflection, structural strength, energy newlineabsorption, and dissipation capacity are all indicators of resistance to this bond. newlineTo provide a dependable force transmission, the required development Length newline(Ld) in tension must be provided while design elements such as diameter, newlineconcrete cover, rebar position, rebar surface texture, bond, unit weight newlineof concrete, and confinement are taken into account. The splitting and brittle newlinefailure of concrete at lap splices of steel rebars are inevitable due to the newlineinadequate lap length of reinforcing steel, insufficient confining reinforcement newlineat lap zones and improper selection to position the lapping of reinforcing steel newlinebars of RC structures. These result in tragic events involving civil infrastructure, newlinesuch as bridges or building collapses, and can cause a large number of fatalities newlineas well as social and economic consequences. As a result, when a lap splice is newlineused, loading, condition evaluation and monitoring must be considered for SHM newlineapplications. Transducers made of Piezoelectric lead Zirconatetitanate (PZT) are newlineincreasingly being employed to monitor diverse engineering constructions due newlineto their advantages of active sensing, low cost, quick response, availability in newlinedifferent shapes, and simplicity for implementation. newline newline