Fiber-Element Model of Posttensioned Hollow Block Masonry Shear Walls under Reversed Cyclic Lateral Loading

Abstract

This paper presents a rational and efficient analytical approach for predicting the nonlinear in-plane flexural behavior of longitudinally posttensioned hollow block masonry shear walls under the action of reversed cyclic lateral loading. The present approach is based on a modified fiber-element (microelement) model of the longitudinally (vertically) posttensioned slender hollow block concrete masonry shear walls with ungrouted cells (i.e., ungrouted longitudinal posttensioning steel) that employs realistic cyclic constitutive rules for the constituent materials. The approach also accounts for the “rocking” type of motion encountered in such walls when subjected to cyclic load reversals in the postcracking range of masonry. The present microelement modeling approach is also valid for slender hollow block masonry shear walls with unprestressed longitudinal steel reinforcement. An important objective of the study is to rationally model the effect of the absence of bond between the longitudinal reinforcing steel (posttensioned or unprestressed) and surrounding masonry, as well as the effect of posttensioning of longitudinal steel on the nonlinear in-plane force-displacement behavior of slender hollow block masonry shear walls subjected to reversed cyclic lateral loading. The proposed approach is implemented to model the in-plane hysteretic force-displacement response of slender posttensioned/reinforced hollow block concrete masonry shear wall specimens with ungrouted cells that were tested under quasi-static reversed cyclic lateral loading. The theoretical predictions are compared with available experimental results for validating the proposed microelement modeling approach.