1 MSc Student, Department of Civil Engineering, University of Calgary, AB, Canada, jianyixian.zhu@ucalgary.ca
2 Structural Engineer-in-Training, Stantec, Yellowknife, Northwest Territory, Canada, jebina15@yahoo.com
3 PhD Candidate, Department of Civil Engineering, University of Calgary, AB, Canada, george.iskander@ucalgary.ca
4 Professor, Department of Civil Engineering, University of Calgary, AB, Canada, ngshrive@ucalgary.ca
ABSTRACT
The Canadian Masonry Design Standard, CSA S304-14, specifies that the in-plane diagonal shear strength of masonry, vm, is a function of the factored moment and factored shear at the location of interest in a wall. Thus, components of the external load effect side of the ultimate limit states design are included in the estimation of the shear resistance, contrary to the basic principle of that method. We have therefore begun to examine experimental methods of determining the diagonal shear strength of masonry as well as the ways that other codes and standards predict the strength of a wall subjected to in-plane shear. Through finite element analysis, we have determined that of the triplet and diagonal shear tests, the triplet test appears to cause stresses in the mortar joint more similar to those in a wall than does the diagonal shear test. The triplet test also appears easier to conduct and more amenable to the application of normal stress. Other codes and standards utilize the results of such tests or estimate the diagonal shear strength from some other strength of the masonry. It is well known that the diagonal shear strength of masonry varies with the applied normal stress in a Mohr-Coulomb relationship, so the effective shear strength will vary in a wall subject to varying moment up its height. Thus, a method needs to be developed to allow for the effect of varying moment on the load effect side of the ultimate limit state design. We review the experimental test methods and the resulting stresses along with the methods used in other codes and standards to lay a foundation for how the clauses in CSA S304 might be revised.
KEYWORDS: in-plane shear, diagonal shear, shear strength, triplet test, diagonal shear test
010-Zhu.pdf
