Development of a wood-concrete composite floor system for rehabilitation of historic mill structures
A wood-concrete composite (WCC) is a high performance floor system which consists of a cast-in-place concrete slab placed upon, and integrally connected to, wood beams below. The floor is up to 4 times stiffer and 2 times stronger than a typical floor where the two materials are not joined. Sound and vibration performance as well as fire resistance are also improved when compared to solely timber floors. This makes the system a logical choice in the restoration and upgrading of old structures.
General interest for reusing old structures (quite often with timber flooring) is on the rise, particularly in New England, where old abandoned mills and industrial buildings are plentiful. Many of these buildings are ideally located next to a river or in a downtown area, having excellent potential for upgrade to residential or commercial use. Through restoration, as opposed to new construction, materials and natural resources are conserved – a primary environmental goal of green building rating systems and city programs.
WCCs are an economical and ecological alternative to removing an old floor and replacing it with a reinforced concrete slab or steel floor. WCCs are used to improve serviceability (i.e. deflection and vibration) as well as to upgrade load capacity of old timber floors. The renovation process involves installing metal shear connectors in the wood members and pouring a cast-in-place concrete slab over the existing timber floor. The floor – typically timber beams with transverse planking – becomes permanent formwork. With this process, construction times are quick and historical ceilings are preserved.
Clouston, P., Schreyer, A. 2006. Wood-Concrete Composites: A Structurally Efficient Material Option. Paper, Boston Society of Civil Engineers (BSCE), Civil Engineering Practice
Clouston, P., Bathon, L.A., Schreyer, A. 2005. Shear and Bending Performance of a novel Wood Concrete Composite System. Paper, American Society of Civil Engineers (ASCE), Journal of Structural Engineering, 131 (9), pp. 1404-1412
Updated: March 20, 2008