Incorporating steel bars as reinforcement in glued laminated timber beams is a technique that aims at better structural performance, allowing the reduction of cross-sections. In the present research, based on experimental results from literature about the reinforcement of timbers beams, a parametric study was carried out with the aid of 164 numerical simulations performed within the scope of linear and nonlinear physical analysis via the finite element method to evaluate, with the aid of analysis of variance (ANOVA), the span, base, height, and the reinforcement ratio influence in the service force, ultimate force, and ultimate displacement. Multiple regression models evaluated by ANOVA were established to estimate the service and ultimate forces and ultimate and service displacements as a function of other variables. The results showed an average increase in the service load of 32% and 49%, and the ultimate load of 42.90% and 66.90%, for reinforcement rates of 2% and 4%, respectively. Regarding the multiple regression models, due to the good values obtained from the adjusted determination coefficients to estimate the values of the forces and the ultimate displacements, these can be used in the pre-design of glued laminated timber beams reinforced with steel bars.
Cross-laminated timber panels (X-Lam panels) are produced for structural use in Service Classes 1 and 2, in accordance with Eurocode 5 and no producer have been able to certify for use in Service Class 3. The swimming-pools are known to be buildings with high hygrometry and the paper describes the use of X-Lam panels in such use, following a project completed in 2012, in Portugal. X-Lam panels are used within the building, through visible surfaces in walls and ceilings. Constructive solutions are presented in order to discuss the way to deal with the service conditions of the building and two years of continuous monitoring are also presented to analyze the validity of design options.
The cross-laminated timber panels (X-Lam panels) are produced for structural use in Service Classes 1 and 2 conditions, in accordance with what is established on Eurocode 5 [. Timber boards are glued together on orthogonal layers, allowing the panel to perform two important characteristics: good dimensional stability and loading in two-way directions. The influence of wood moisture content on the feasibility of cross-laminated timber is described in this paper regarding the dimensional stability of the panels when applied in high moisture locations. Several European Technical Approvals, state the low importance of the dimensional variations with moisture content of this type of panel, but some reference values can be found in other technical documents. The French Avis Technique [[[1 reference the value of 0.01mm/m for in-plane deformation (per percentage of timber moisture variation) and the TRADA Wood Information Sheet, WIS 2/3-62 [1, refers the maximum value of 0.02mm/m for the same conditions.The use of the X-Lam panels in Service Class 3 can not be used, concerning the high level of stressing in glue lines, and no producer has yet certified it for this Service Class. Moreover, the French Avis Technique doesnt allow the use of X-Lam panels in swimming-pools due to high hygrometry, even for conditions corresponding to Service Class 2.Cross laminated timber panels are widely used across Europe but are giving the first steps in Portugal at the moment. The first big project was finished in spring 2012 in Almada, comprising a building integrating a 25 meter in-door swimming-pool and a gym. In order to assess the behavior of the timber structure, due to the non-conventional using of the X-Lam panels, a monitoring program was started immediately after building construction. The results obtained are presented and discussed in this paper.
