Lumber-Boxed Concrete Structural System-Concept and Preliminary Analysis

摘要

Lumber has the advantages of being a lightweight construction material, easy to handle, and environmentally benign. However, large creep deflections and significant issues with sound transmission, particularly the footfall problem, generally limit lumber use to small spans and low-rise buildings. A concrete topping on lumber subfloors may mitigate some of these issues, but even with well-engineered wood systems, the spans are relatively short. In this study, a new structural system is analytically explored. Called a lumber-boxed concrete structural system, the dual system utilizes the positive attributes of both dimensional lumber and reinforced concrete; composite action is not a requirement of the system. A stress-block approach is developed to calculate strength and deformation behavior. An analytical stress-block-based moment-curvature analysis is performed on the lumber-boxed concrete structural elements. Results show that the structural lumber-boxed concrete members may have better strength and ductility capacities when compared to an equivalent size ordinary reinforced concrete member.