Prefabricated Roof Beams for Hardened Shelters.

摘要

The objective of this research was to develop a procedure for designing roof beams for a new generation of rapidly erected protective shelters. The cost of these roof elements should be minimized consistent with the performance constraints, and made of lightweight elements. Identifying a concept satisfying the above criteria was accomplished by developing an analysis procedure, designing a number of candidate beams, evaluating their respective performances, estimating costs, and finally performing laboratory tests on prototype of the recommended concept. The design procedure utilizes a dynamic analysis of the beam based on procedures contained in design manuals, building codes, and a survey of the technical literature. Validation by finite element analysis was done to provide a check of the simplified analysis. Three concepts for prefabricated elements were considered: conventionally reinforced concrete, prestressed concrete, and a steel beam with a composite concrete slab. Based on the results of the concept evaluation, a test program was designed and conducted to validate the steel-concrete composite beam. The prototype beams incorporated special reinforcing designed to confine the concrete and greatly enhance its ductility and ultimate strength. The results of these tests showed that the design procedure accurately predicts the response of the steel-confined concrete composite beam. Reinforced Concrete, Prestressed Concrete, Steel-Concrete Composite, Roof Beams, Blast, Survivability, Confined Concrete Testing.