Quantifying MEPFP Mass-Timber Trade Efficiency Through Vertical Mechanical Fastener Analysis

Abstract

Touted attributes of mass-timber structures include its efficiency in both erection and labor productivity. These efficiencies are a result of differing methods, induced by varying contractors, and are impacted by site specific variables. This study explores efficiency related to overhead fastener applications installed by MEPFP trades. Fastener installation time in an overhead rebar reinforced concrete beam is compared to that installed in a mass-timber structural beam to determine efficiency disparities (if any). Two sets of fasteners are compared in the differing materials: one for heavy and the other for light duty applications. A total of sixty fasteners were installed, consisting of two sets of fasteners, installed in both concrete and mass-timber. Results were analyzed with two independent t-tests to determine statistical significance and mean difference between fastener and material type. The study found that heavy-duty conventional overhead concrete fastener installation takes significantly longer (Fastener A-Conc. M=12.82 seconds) than mass-timber fastener installation (Fastener A-MT. M=1.01 seconds), t(26)=38.72, p=<.001. Additionally, light-duty fasteners share similar results in concrete (Fastener B-Conc. M=12.18 seconds) compared to mass-timber (Fastener B-MT M=2.32 seconds) conditions; t(23)=33.56, p=<.001. This study provides evidence that mass-timber offers significant time savings per each overhead fastener installation, when compared to traditional concrete structures. These results can be used for construction planning, productivity rates databases, and cost analysis.