Strain-based Damage Classification of Slender Reinforced Concrete Shear Walls

Abstract

This study investigated the behaviour of Reinforced Concrete (RC) shear walls under quasi-cyclic loading. The study's main objective was to comprehend the mechanics of load transfer and the progression of damage in slender, intermediate, and squat shear walls. It aimed to develop equations that relate strain to sectional properties of walls and propose strain limits for different damage states, such as rebar yielding, onset of concrete spalling, and core concrete crushing. Currently, the focus of the work is primarily on slender shear walls. Displacements of slender shear walls under lateral loading is mainly governed by flexural deformations. The fundamental stages of damage in slender shear walls are studied from mechanics of load transfer. The critical damage states of slender shear walls are identified based on residual lateral capacity of wall. For slender RC shear walls, the identified critical damage states are yielding of rebar, spalling of cover concrete, crushing of core concrete, and buckling of longitudinal rebars. Extreme fibre compressive strain is chosen as Engineering Response Parameter (ERP) for unambiguous identification of critical damage states. Available published details of quasi-cyclic experimental testing of slender RC shear walls are used to determine values of compressive strains at critical damage states. The published literature reported displacement values at occurrence of some of the critical damage states. Extensive literature survey is done to gather the experimental data of shear walls under cyclic loads. Experimental data of twenty-four planar slender RC shear walls is reported displacement corresponding at least one of the critical damage states. These published experimental force-displacement relationships are analytically reproduced to determine extreme fiber compressive strains at critical damage states.