Title:
Flexural Behavior of Joint Reinforced Block Masonry Walls
Author(s):
Ahmad A. Hamid, Catherine Chia-Calabria, and Harry G. Harris
Publication:
Structural Journal
Volume:
89
Issue:
1
Appears on pages(s):
20-26
Keywords:
bonding; concrete blocks; cracking (fracturing); flexural strength; masonry; joints (junctions); reinforced masonry; reinforced masonry; reinforcing steels; walls; wire reinforcement; Structural Research
DOI:
10.14359/1279
Date:
1/1/1993
Abstract:
Wire bed-joint reinforcement has been used widely over the years for control of cracks due to temperature and shrinkage, for continuity in multiple wythe walls, and to satisfy arbitrary minimum code requirements in the horizontal direction. However, the structural significance of joint reinforcement in block masonry walls is not well established. This paper presents an experimental study of the behavior of horizontally spanning joint reinforced block masonry walls under out-of-plane monotonic lateral loading. Five full-scale wall panels were tested to determine the effect of amount and type of horizontal steel and bond pattern (running versus stack bond) on wall behavior including cracking moment, load-deflection relationships, and flexural strength. Correlation between flexural strength test results and the UBC-88 code strength design method is presented. The results showed that the shape of the load-deflection curve was a function of the spacing and type of reinforcement. The walls exhibited very little post-peak inelastic deformation due to the limited inelastic strain of the cold-drawn joint reinforcement. Joint reinforcement did not influence the cracking load significantly; however, the flexural strength was increased significantly. Bond pattern did not affect the ultimate moment carrying capacity of the walls but significantly affected the cracking moment. It is concluded that as the UBC strength design method gives a reasonable estimate of wall flexural strength, a method based on strain compatibility would provide more accurate results.