1336478 (McConnell). The primary objective of this research is to prove that widespread reuse of structural steel in buildings would be structurally-sound engineering practice with significant environmental benefits. The reuse of structural steel is currently exceedingly rare and, furthermore, reusing primary structural steel members as primary structural members is even less common. Once it can be shown that reuse of structural steel is generally acceptable or the specific conditions in which reuse of structural steel is appropriate are identified, this will lay the foundation for a new paradigm for reuse of structural steel and transform current construction practices resulting in significant environmental benefits. Original data that are to be generated through this research is detailed information on construction-induced stresses through field testing using established and novel monitoring and inspection techniques combined with computational structural analysis. The work will also result in improved understanding of the holistic stress state within a building system, which can be used to optimize future designs, building layouts, and conventional and deconstruction-focused connection methods. Such practice would dramatically reduce the need for recycling steel members, and the associated minimum estimates of 10 GJ of energy and 0.92 tons of CO2 emissions per ton of steel. The outcome of this research and its complementary activities is targeted to cultivate a cultural shift in the way in which buildings are designed, constructed, deconstructed, and repurposed in order to have a more thoughtful regard for energy and natural resource consumption. Through four tasks, data to support or disprove the primary hypothesis that structural steel members can safely be reused will be generated by creating a stress envelope of potential stress states for common applications. In support of the second hypothesis of this research (conditions most likely to impair future structural usefulness are construction-induced stresses and connection stresses), considerations of construction sequencing and/or analysis in the vicinity of connections will be common to all research tasks. Task 1 will be a laboratory pilot case for later field instrumentation to be installed in Task 2 to obtain novel information on the construction-induced stresses in typical buildings. In Task 3, the residual stresses in and structural performance of decommissioned steel members will be quantified. Through the combination of Tasks 2 and 3, the actual stresses in a suite of steel building members will be known at all stages of a steel member?s life cycle (construction and service-life from Task 2; end of service-life from Task 3). The information from these select members and structures will be used to predict the peak life-history stresses via computational structural analysis in Task 4. Through the monitoring efforts in Tasks 1 and 2 it will also be determined if novel monitoring and inspection methods have the ability for evaluating suitability for reuse on a specific individualized basis for any member that is a future reuse candidate. The broader impact of the proposed research and its integrated activities is to initiate a cultural shift towards a more thoughtful and environmentally-friendly regard for the manner in which materials are used and reused in our profession and society. Through this research it is anticipated that the frequency at which steel is reused will increase, to achieve reductions in energy consumption and greenhouse gas emissions in the construction industry. Through a comprehensive plan for disseminating the research topic and results, the concept of reusing materials will be promoted within the scientific, college, pre-college, and local communities. Outreach activities to expose a diverse population of pre-K students to the concepts of sustainability and the field of civil engineering in a manner that is integrated with existing research-based best-practices in pre-K literacy education is also proposed.
