View PDF

Abstract

According to the U.S. Energy Information Administration, construction and use of buildings consumed almost half of the total energy used in the United States in 2012. Design for Deconstruction (DfD) of buildings, first proposed in the 1990s, aims to minimize the environmental impacts and reduce the pollution and waste produced during construction and demolition of buildings by reclaiming the materials at the end of the service life of buildings. Contrary to the conventional material flow in buildings, which starts with the extraction or recycling of raw materials and ends with the disposal of debris in landfills, DfD attempts to close this loop by reusing the salvaged materials in future construction projects. As the most ubiquitous type of structural steel framing for commercial and residential buildings, traditional steel-concrete composite flooring system makes the most efficient use of the two materials, with steel being subjected to tension and concrete resisting compression. However, in this system the concrete slabs are poured integrally with the supporting steel framing systems, inhibiting the separation and reuse of the structural components.

The objectives of the proposed research are to develop new structural system concepts for deconstructable steel and steel-concrete composite construction to facilitate DfD coupled with the use of recycled materials in sustainably optimized construction. The proposed system not only maintains the benefits offered by composite construction but also enables disassembly and reuse of the structural components.

This report illustrates the deconstructable composite floor system utilizing clamping connectors. This floor system is anticipated to be used along with all-bolted construction for the remainder of the structure to facilitate deconstruction. A solution for connecting all the precast concrete planks in their plane using threaded rods is also presented. Diaphragm behavior is then briefly introduced, and computational results are provided to demonstrate the diaphragm response of the deconstructable composite floor system. The experimental program for investigating the performance of the system is introduced. Pushout tests are conducted to quantify the strength and ductility of the clamping connectors and evaluate the influences of the parameters. The test results along with collaborating analysis results for the pushout tests indicate that the strength of the ductile clamping connectors is comparable to that of the steel headed stud anchors. In addition, the behavior of the clamping connectors will be further validated through full-scale beam tests in which the flexural behavior of the deconstructable composite beams is investigated comprehensively. This report culminates with conclusions and recommendations for future work.

Further Information

Further information on this project, including additional reports and references, can be found on the Design for Deconstruction website here:

https://coe.northeastern.edu/research/dfd/publications.html