Shear Strength of Structural
Walls Subjected to Load
Study verifies limits specified in the ACI 318 Code
by Merve Usta, Abdallah Alhmood, Julian Carrillo, Antoni Cladera, Lucas Laughery, Santiago Pujol, Aishwarya
Puranam, Jeffrey Rautenberg, Halil Sezen, Lesley H. Sneed, and Duy V. To
If a structure is to resist earthquake demands, its elements
must maintain their strengths through load and
displacement reversals. This article examines whether the
shear strength of structural walls is sensitive to load reversals
applied before yielding of longitudinal reinforcement.
Previous studies have suggested that shear strength of
structural walls decays through load cycles applied before
yield. Barda et al.1 tested three similar structural walls—two
under monotonic and one under cyclic loading—and
attributed an inferred 10% decrease in shear strength to the
potential effect of cycles. More recently, Ruggiero et al.2
tested shear panels under cyclic loading and inferred a
reduction in shear strength by comparing results from cyclic
tests with expected monotonic capacities and previous
monotonic tests. Gulec et al.3 and Gulec and Whittaker4
quantified the effects of cycles applied after shear failure.
Joint ACI-ASCE Subcommittee 445-B, Shear & Torsion-
Seismic Shear, has compiled a database (the ACI 445B
database) with results from more than 500 tests on reinforced
concrete structural walls. It must be noted that the database
comprises structural walls and does not include shear panels.
While results from tests of panels can be useful for formulating
constitutive relationships, using them to develop understanding
of the response of walls would require detailed projections
involving uncertainties beyond the effect of cycles.
This article reports on a detailed review of the data within
the ACI 445B database to test the sensitivity of shear strength
of structural walls to lateral load reversals. We emphasize that
our study was focused on strength, not deformation capacity.
Our motivation is to provide engineers with the means to
avoid shear failure in structural walls before yielding of the
42 MAY 2019 | Ci | www.concreteinternational.com
longitudinal (vertical) reinforcement, as failure before yield
hinders the ability of a wall to control building drift. After
yield, the strength is controlled by the yield stress of the
longitudinal reinforcement, and the strength can be estimated
adequately using conventional methods.
Shear Wall Database
The ACI 445B database includes data from experiments on
structural walls subjected to static (cyclic and monotonic)
loading. All data were collected from the published literature.
The database has five parameter categories: general
information, geometric properties, material properties,
experimental programs, and experimental results. For each
experiment, the dataset includes related reports, parameters,
data files, media (photos and video), drawings, and diagrams.
The database is expanded and vetted several times per year
by Joint ACI-ASCE Subcommittee 445-B. The study
summarized herein was carried out using the April 24, 2017,
version of the database, when it contained data from 521
experiments.5 Additional details on the database are provided
in the work by Usta.6
Our investigation focused on testing the sensitivity of the
shear strength of structural walls to load cycles applied before
yielding of the longitudinal reinforcement. We also evaluated
the design expression in the ACI 318 Code currently used to
proportion walls to prevent shear failure (ACI 318-14,
Out of the 521 walls in the compiled database, we selected
260 walls with detailed information about reinforcement