Self-tensioning system for long-span wooden structural floors

• Published in: Construction & building materials Vol. 102; pp. 852 - 860
• Main Authors: Estévez-Cimadevila, J., Otero-Chans, D., Martín-Gutiérrez, E., Suárez-Riestra, F.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.01.2016; Elsevier B.V
• Subjects: Analysis; Floors, Wooden; Long-span; Post-tensioning; Pre-stressing; Self-tensioning; Strains and stresses; Stress relaxation (Materials); Stress relieving (Materials); Wooden floors; United States; Pre-stressing; Wooden floors; Self-tensioning; Post-tensioning; Long-span
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2015.11.024

•A novel self-tensioning system limiting deflections in wooden floors is presented.•The system is automatically activated when load is placed on the structural element.•The intensity of the tensioning force varies with the magnitude of the applied load.•The system is particularly interesting for application in long-span wooden floors.•Wooden floors with π-type cross sections are analyzed. A patented self-tensioning system for long-span wooden structural floors is described that increases the performance of the deflected sections in terms of both resistance and deformation. The system is based on a force multiplier mechanism composed by two connecting rods which are secured to a post-stressing tendon. The mechanical device is activated by the transmission of the load from the structural element to the supports, causing an elongation and stressing the tendon. This transmission comes with a slight vertical displacement of the supports. Throughout this system, the intensity of the tensioning force varies with the applied load; thus, a more favorable bending moment distribution from the load is obtained, and the relative deformations of the different sections of the piece are reduced. This article presents a comparative study of the structural behavior of π-shape cross section wooden structural floors with spans from 9m to 18m, comparing sections with and without pre-stress, and sections with the self-tensioning system.