Experimental study of reinforced masonry beams

Abstract

An experimental program on reinforced concrete masonry beams was conducted aiming to better understand the behavior of reinforced masonry beams. The beams were designed to fail in flexure, assessing cracking patterns, maximum displacement, ultimate bending moment, and maximum flexural and axial compression strain. The experimental program included 12 reinforced masonry beam tested under flexure and built with bond-beam and hollow concrete blocks. Also, two type of prism were built and tested; one type stacked into the block greater dimension allowing testing with compression in the same direction as in the beams; and the second type as standard grouted prisms. Results indicate an average masonry compression strength parallel to bed joint 25% lower than the masonry compression strength in the other direction (perpendicular to bed joints). There was a significant increase on the beam stiffness due to the construction of one more block course. The model used to calculate the ultimate bending moment led to values close to the experimental result (difference of about 15%). Finally, the ultimate average shortening strain of masonry at axial compression was 50% lower than at flexural compression.