Rapidly assemled emergency shelters made from "green" materials

Abstract

This paper describes a research project conducted by the Department of Architectural Engineering, the Department of Architecture and the Department of Materials Engineering at California Polytechnic State University. We are developing a habitable temporary shelter that is durable, sustainable, economical, and rapidly assembled. A basic, repeatable module of the design is a hyperbolic paraboloid (hypar) panel, generated from extruded straight boards of high density polyethylene (HDPE) reinforced with waste-stream agricultural fibers. Our research has shown that the hypar is well suited for a rapidly assembled emergency shelter because it can be generated from straight line segments which can be trucked to the disaster site. Then, using our proposed assembly method, a large span thin shell structure can be rapidly constructed. The paper will discuss the fabrication and the testing of the "green" composite material used for these shelters. This composite material itself was the starting point for a number of design ideas. The uniqueness of the material; its stiffness, strength, and ecologically friendly nature spurred us into thinking about how we could incorporate it into structures. Before designing with this material, we addressed some of its mechanics issues, namely how could we characterize this material under tensile loads and under bending loads. Also, we performed a detailed study of how the material reacted to intense ultraviolet light. Having addressed the mechanics, we began the task of designing a structure with this material. We chose an emergency shelter as our design goal because we decided that an emergency shelter composed of hypar modules could be constructed from straight-line segments of this unique, extruded material.