Allowable Shears for Plastered Straw-Bale Walls

Abstract

Although straw-bale construction originated in the midwestern United States in the late 1800s, the engineering of plastered straw-bale walls to resist in-plane lateral loads is a modern development. Relevant experimental studies are reviewed and allowable shears are developed for use in design for wind and seismic loading. Clay, soil-cement, lime, lime-cement, and cement plasters having various thicknesses and reinforced with welded steel wire mesh, woven steel wire mesh, or polypropylene mesh are considered. Experimental values are adjusted on the basis of moment-curvature analysis results to account for lower-bound model code material strengths, plaster thicknesses, and mesh reinforcement. A conventional model for shear strength is used to provide a preliminary assessment of true shear strength. The resulting design values and associated detailing requirements are summarized in a format suitable for implementation in model code provisions for straw-bale construction.