Maysoun Ismaiel, Yuxiang Chen and Carlos Cruz-Noguez
Maysoun Ismaiel, Ph.D. Candidate, Department of Civil and Environmental Engineering, University of Alberta, 116 St & 85 Ave, Edmonton, AB, Canada, ismaiel@ualberta.ca
Yuxiang Chen, Assistant Professor, Department of Civil and Environmental Engineering, University of Alberta, 116 St & 85 Ave, Edmonton, AB, Canada, yuxiang.chen@ualberta.ca
Carlos Cruz-Noguez, Assistant Professor, Department of Civil and Environmental Engineering, University of Alberta, 116 St & 85 Ave, Edmonton, AB, Canada, cruznogu@ualberta.ca
ABSTRACT
To reduce the energy consumption in masonry buildings and comply with newer, more stringent energy codes, one possibility is to increase the thermal resistance of masonry wall systems. However, this approach comes with several challenges. One of them is the inability of a quick estimate of the effective thermal resistance of masonry walls with sufficient precision due to the complexity of masonry construction. Currently, the options to deal with non-typical details are; using simplified assumptions that often lead to inaccurate results (e.g. area weighted method), or conducting expensive and time-consuming numerical modelling (e.g. linear transmittance method). This study focuses on concrete masonry cavity walls. The main objective of this paper is
to provide -using numerical modelling- the overall R-values of common concrete masonry cavity wall assemblies in form of simple design charts. The numerical modelling results were validated
with experimental results provided in the literature. The design charts combine the mechanical (the masonry compressive strength, (fm′)), thermal (overall R-value) and physical (density of blocks) properties of different cavity wall assemblies. These charts aim to guide the designers to reliably estimate and choose the appropriate structural and thermal properties of common concrete
masonry walls. Many parameters are addressed by using numerical modellings such as the type and density of the concrete blocks, the insulation R-value, as well as, the ties and shelf angle’s
shape and material. The numerical models and design charts are also used to evaluate and compare the impact of different parameters on the overall thermal resistance of masonry walls.
KEYWORDS: experiments, masonry cavity walls, numerical modelling, R-value charts, R-value estimation, thermal Resistance
