Experimental Evaluation of Connector Systems for Wood-Concrete Composite Floor Systems in Mill Building Renovations

By Peggi L. Clouston and Alexander C. Schreyer.

Published by The International Journal of the Constructed Environment

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Article: Print $US10.00
Article: Electronic $US5.00

A comparison study was conducted on four types of wood and concrete floor systems intended for use in upgrading historic mill buildings. These systems involved various shear fasteners to connect regular strength concrete slabs to the original historic wood decking of the floor system. The approach was intended to provide an increase in strength and stiffness of the floor system, thereby offering a technical solution for common floor performance problems encountered in mill re-use projects. Twenty-five specimens of full-size, wood-concrete composite beams were manufactured and tested to failure in bending. The four connection types considered were: a) nails, b) shear keys with anchors, c) metal plates, and d) a novel connection in which concrete aggregate was embedded into epoxy and then used as the shear connector. Overall, the epoxy-aggregate connection showed the highest stiffness as well as highest strength of all connector types. While the nails had a lower stiffness, their strength was higher than both the metal plate and the shear key connections. All systems outperformed the unconnected control sample both in terms of strength and stiffness, proving that increasing both the strength and stiffness of historic mill floors is possible using a variety of commonly available fasteners.

Keywords: Adaptive Reuse, Composite Action, Experiment, Floor Design, Historic Preservation, Mill Buildings, Strength, Stiffness, Wood and Concrete Composite

The International Journal of the Constructed Environment, Volume 2, Issue 1, pp.131-144. Article: Print (Spiral Bound). Article: Electronic (PDF File; 1.202MB).

Dr. Peggi L. Clouston

Associate Professor, Department of Environmental Conservation, University of Massachusetts, Amherst, MA, USA

Dr. Clouston currently teaches structural timber design, bio-based building composites, and statics and strength of materials (tectonics) for architects, engineers, and construction technologists at the University of Massachusetts. Her research program focuses on the structural behavior and efficient use of sustainable, bio-based composite materials. Current research topics include: wood-concrete composite systems, laminated bamboo lumber, innovative timber connections, and computational modeling of wood-based composites. She has been a registered professional engineer (APEGBC) since 1992 and an associate member of the American Society of Civil Engineers since 2001. She serves on numerous national review panels and committees.

Dipl.-Ing. Alexander C. Schreyer

Lecturer, Department of Environmental Conservation, University of Massachusetts, Amherst, MA, USA

Combining backgrounds in structural engineering, wood science and digital design, Mr. Schreyer’s interests span the entire range of planning and design of buildings and structures. He specializes in the design and construction of mainly heavy-timber type (e.g. glulam) structural systems. This is complemented by a strong interest in computer applications and web-based solutions in structural engineering, construction and architecture. He is a lecturer in the Building and Construction Technology program at the University of Massachusetts (UMass) in Amherst, MA. He teaches classes in computer-aided design) and building information modeling), building materials and construction methods, wood properties, as well as a capstone graduate structural design class in architecture. In his research, he focuses on the behavior of wood-based structural systems, with a particular interest in innovative connection systems for wooden structures. Other foci are the development of software applications for CAD design and structural optimization.