Concentric and Eccentric Compression Experiments of Plastered Straw Bale Assemblies: Fid-Bau Portal

Concentric and Eccentric Compression Experiments of Plastered Straw Bale Assemblies

Vardy, Stephen / MacDougall, Colin

Abstract

Straw bale construction is a nonconventional technique that involves stacking common straw bales and then applying layers of plaster to form load-bearing walls. The straw bales provide insulation, whereas the plaster protects the bales from moisture and provides strength and stiffness for the wall. This technique has experienced a revival because of its environmental benefits. Because there are few codes and standards for this construction technique, engineers are often required to check and approve designs using straw bale construction before building permits will be issued. An understanding of the behavior of straw bale construction is needed for engineers to approach this system with confidence. A model for predicting the response of plastered straw bale walls subjected to concentric and eccentric compressive loading was proposed in this paper. The model was verified using experimental tests of wall panels loaded until failure. The eccentrically loaded specimens were found to have load-deflection behavior (lateral and vertical) that could be predicted by theoretical models based on the stress-strain behavior of the lime-cement plaster. Failure of the specimens was observed to occur as a result of compressive failure of the plaster and was predicted based on the theoretical models.