A Study of the Deflection of Prestressed Masonry Walls

Test specimens, which were 72 in. x 36 in. x 4 in. in size with two different end anchorages, were subjected to out-of-plane loads to study their load-deflection behavior. Load-deflection relations for prestressed masonry walls are presented along with laboratory test results. Three analytical methods of calculating masonry deflection are discussed and compared with the experimental test results developed up to the ultimate stage. In the first method, moment-curvature relations were derived from assumptions based on well-established theories of prestressed concrete member behavior and material properties. The other two methods included for comparison are the Uniform Building Code (UBC) formula and the Horton and Tadros method. All methods were close to the actual test data at the ultimate strength level. The study showed that both the UBC equation and Horton and Tadros method are conservative in predicting deflections compared to the actual behavior of masonry. Moment- curvature showed the best prediction of behavior up to the ultimate strength.