scholarly journals Evaluation of Moisture and Decay Models for a New Design Framework for Decay Prediction of Wood

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 721
Author(s):  
Jonas Niklewski ◽  
Philip Bester van Niekerk ◽  
Christian Brischke ◽  
Eva Frühwald Hansson

Performance-based, service-life design of wood has been the focus of much research in recent decades. Previous works have been synthesized in various factorized design frameworks presented in the form of technical reports. Factorization does not consider the non-linear dependency between decay-influencing effects, such as between detail design and climate variables. The CLICKdesign project is a joint European effort targeting digital, performance-based specification for service-life design (SLD) of wood. This study evaluates the feasibility of using a semi-empirical moisture model (SMM) as a basis for a digital SLD framework. The performance of the SMM is assessed by comparison against a finite element model (FEM). In addition, two different wood decay models (a logistic, LM, and simplified logistic model (SLM)) are compared. While discrepancies between the SMM and FEM were detected particularly at high wood moisture content, the overall performance of the SMM was deemed sufficient for the application. The main source of uncertainty instead stems from the choice of wood decay model. Based on the results, a new method based on pre-calculated time series, empirical equations, and interpolation is proposed for predicting the service life of wood. The method is fast and simple yet able to deal with non-linear effects between weather variables and the design of details. As such, it can easily be implemented as part of a digital design guideline to provide decision support for architects and engineers, with less uncertainty than existing factorized guidelines.

2010 ◽  
Vol 43 (10) ◽  
pp. 1397-1412 ◽  
Author(s):  
Irina Stipanovic Oslakovic ◽  
Dubravka Bjegovic ◽  
Dunja Mikulic

Author(s):  
Preston D. Vineyard ◽  
Brad J. Pease ◽  
Don Bergman ◽  
Armin Schemmann ◽  
Jacob E. Andersen ◽  
...  

<p>The Governor Mario M. Cuomo Bridge has replaced the existing Tappan Zee Bridge in New York. The new bridge was built by Tappan Zee Constructors, LLC. and is owned and operated by the New York State Thruway Authority (NYSTA). The new bridge is a 3.1 mile long crossing of the Hudson River and has an iconic main span structure, consisting of twin cable-stayed bridges, with 1,200’ main spans and 515’ side spans. Each new bridge carries four traffic lanes and the new crossing has been designed to accommodate the future addition of a rail bridge between the roadway decks. Utilizing a probabilistic-based service life design approach, the new bridge has been designed for a minimum 100-year service life before major maintenance for non- replaceable components, such as the foundations, sub-and superstructures. This paper provides the design features of the main span bridge and describes the design solutions, such as the use of fib Bulletin No. 34 to address the Service Life Design of the concrete components to address the durability challenges of this world- class project.</p>


Author(s):  
Maxime Verbist ◽  
Lina Nunes ◽  
Dennis Jones ◽  
Jorge M. Branco

2018 ◽  
Vol 8 (3) ◽  
pp. 224-245 ◽  
Author(s):  
Mark Gavin Alexander

The paper presents an overview of current knowledge and progress in service life design and modelling of concrete structures, taking an international view but also giving local examples from South Africa. It raises the question of why service life modelling is needed, and indicates that modern demands for longevity, durability, and sustainability of concrete structures cannot be fulfilled without service life modelling. It addresses the current approaches to durability design and specification and concludes that a move to performance-based approaches is imperative if progress is to be made. Examples from international experience are cited to illustrate progress that has been made. Lastly, the paper discusses ways of moving forward, recognizing that the philosophical bases are already firmly in place in the form of general code formulations, but these need to be converted into useful approaches.


2012 ◽  
Vol 52 (10) ◽  
pp. 1713-1723 ◽  
Author(s):  
Zheng-jian Liu ◽  
Jian-liang Zhang ◽  
Hai-bin Zuo ◽  
Tian-jun Yang

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