In‐plane and out‐of‐plane behavior of confined masonry walls for various toothing and openings details and prediction of their strength and stiffness

Abstract

Summary Eight half‐scale brick masonry walls were tested to study two important aspects of confined masonry (CM) walls related to its seismic behavior under in‐plane and out‐of‐plane loads. Four solid wall specimens tested to investigate the role of type of interface between the masonry and tie‐columns, such as toothing varying from none to every course. The other four specimens with openings were tested to study the effectiveness of various strengthening options around opening to mitigate their negative influence. In the set of four walls, one wall was infilled frame while the other three were CM walls of different configurations. The experimental results were further used to determine the accuracy of various existing models in predicting the in‐plane response quantities of CM walls. Confined masonry walls maintained structural integrity even when severely damaged and performed much better than infill frames. No significant effect of toothing details was noticed although toothing at every brick course was preferred for better post‐peak response. For perforated walls, provision of vertical elements along with continuous horizontal bands around openings was more effective in improving the overall response. Several empirical and semi‐empirical equations are available to estimate the lateral strength and stiffness of CM walls, but those including the contribution of longitudinal reinforcement in tie‐columns provided better predictions. The available equations along with reduction factors proposed for infills could not provide good estimates of strength and stiffness for perforated CM walls. However, recently proposed relations correlating strength/stiffness with the degree of confinement provided reasonable predictions for all wall specimens. Copyright © 2016 John Wiley & Sons, Ltd.

Sustainable housing using confined masonry buildings

“…Again to construct a proper RC frame building with infill walls requires technical skills and finances. Much of India is prone to substantial earthquakes Normalized out-of-plane displacement of infill wall with respect to CM walls at different in-plane drift (damage) levels [22,23] and construction of earthquake-resistant housing for families in the economically weaker sector, and the lowerincome group is undoubtedly challenging. Confined masonry can be a useful construction technology because this practice does not require new or advanced construction skills or equipment.…”

“…Further, the load-deformation behaviour depends on various factors, such as wall aspect ratio, material strength, type of wall-to-tie-column interface, detailing of tie-columns, wall openings and overburden pressure. [19][20][21][22][23][24][25][26][27].…”

“…Hence, the combined effect of in-plane and out-of-plane forces aggravates the extent of the damage. Singhal et al [22,23] tested halfscaled CM wall specimens with the different connections at the wall-to-tie-column interface ( Fig. 6) and considered the successive applications of out-of-plane and in-plane loading.…”

“…Wall specimens prepared for the experimental investigation[22,23] Comparison of seismic response of infilled RC frame and CM walls[22,23] …”

Low‐seismic damage strategies for infilled RC frames: shake‐table tests

“…The shake-table has size of 1.5 × 1.5 m and can generate unidirectional excitations of acceleration up to 1 g and frequency range of 0-50 Hz. Due to the weight capacity, loading limit and geometric restraints of the facilities, the specimens in shaking table tests were normally scaled down to have a size in the range of one-half to one-fourth of the original prototype sizes [3,26,27]. In this study, the geometric scale factor for the specimens was one-third, and the model materials have the same properties as the prototype structure which conveniently led to a Young's Modulus scale factor equal to unity.…”