Mass timber (MT) offers viable eco-conscious solutions within the building industry, with its high strength ratings, dimensional stability, light weight and renewable nature enhancing its status as a low carbon alternative to conventional building materials like steel and concrete. Moisture intrusion, coupled with the inherent organic nature of wood pose...
The engineering community is increasingly moving towards the design of seismic force-resisting systems that limit post-earthquake damage and reduce downtime to increase urban resiliency. For example, structural spines can be used to provide an elastic load path to impose a more uniform drift distribution with building height, thereby reducing the...
Includes Partial Least Squares Regression and Univariate Linear model RStudio code and results in PDF form for each of the three specimen populations scanned by two different light sources. Also included is a generalized PDF document and RMarkdown document for predicting percent wood failure.
Structural engineered wood manufacturers need a quantitative measurement technique to determine the ratio of wood to adhesive failure in their shear specimens. Visual estimation of percent wood failure has long stood as an extremely subjective quality control approach according to ASTM D5266 – Standard Practice for Estimating the Percentage of...
This thesis consists of three manuscripts related to the methodology of evaluating charring behavior in cross laminated lumber panel specimens subjected to fire performance tests on cross-laminated lumber panel specimens. The topic of the first manuscript is the measurement of char rates of unprotected CLT layups fabricated with ponderosa pine...
Conflicts and disasters displace millions of populations worldwide. There is a need for rapid and affordable housing to cater to the needs of the displaced and unhoused population. Experience from previous post-disaster responses shows that temporary housing should be rapidly deployable, planned for months to years, and should be environmentally...
In the search to improve and incorporate nano and renewable materials into urea-formaldehyde (UF), several researchers have incorporated cellulose nano fibrillated (CNF) into the adhesive. This study aimed to find an optimal way of incorporating CNF into UF and understand how CNF interacts with and changes the properties of the...
With growing interest in mass timber, especially mass timber panels (MTP), there has been a need to better understand their structural properties. One of the most versatile uses for MTP are as floor systems. Under new code provisions, these floors can be utilized in new and taller building types, but...
Restoration programs effectively prevent or mitigate wildfires and pest outbreaks in the forest lands. The most common approach is to selectively harvest smaller and dead trees in order to preserve larger and superior trees. Ponderosa pine, Pinus ponderosa, (PP) lumber is one of the common species harvested from restoration programs...
Timber-concrete composite (TCC) solutions originated in the early twentieth century. There has been a renewed interest in TCC solutions in modern mass timber buildings, especially for floor systems. However due to lack of data, design standards, and code acceptance, TCC solutions require that new mass timber solutions be tested, and...
Post-tensioned (PT) self-centering shear walls were designed to reduce structural damage from seismic activity. However, these lateral force resistant systems experience post-tension loss negatively affecting the re-centering capability due to delayed deformations experienced by engineered wood products over time. The long-term mechanical response of mass-timber panels to in-plane PT loads...
Spraying of liquid adhesive onto wood surfaces has shown to be a highly effective and efficient method of application across many different wood-based composite industries. However, the dynamics of spraying are extremely variable and distribution can be affected by liquid properties (rheology, molecular weight distribution, and temperature), application parameters (disk...
Forest composition in Paraguay has been in a state of change for the past half century due to land management practices, forest fragmentation, and deforestation for agriculture. How these factors affect dendrological diversity and wood anatomy in Paraguay is not well understood. This thesis documents Paraguayan forest composition on the...
As a new product patented by Freres Lumber Company in 2018, little information exists for manu-facturing procedures of mass plywood panels (MPP). At first glance, MPP may appear to be ply-wood, laminated veneer lumber (LVL), or similar to conventional cross-laminated timber (CLT). Often manufacturers, as well as users, of MPP...
Civil engineers are aware of the impacts of structures on the global environment but the environmental impacts of a fire within these structures remains unknown. Fires present a unique hazard as it is difficult to predict the probability of the occurrence and the intensity. Traditional methods to identify the environmental...
Equipment and technology suppliers to the US forest sector are confronting challenges and opportunities to meet the need for disruptive changes in an increasingly complex business environment. Open innovation is crucial for survival and success in the complex and changing operational environment due to its inherent openness and interdisciplinary nature....
Generally presented as a preferred social norm based on both ethical considerations and legislative demands, gender equality has been highly encouraged in recent years. For instance, The United Nations Sustainable Development Goals for 2030 call out achieving gender equality and empowerment of women. However, although there are multiple efforts to...
Accelerated weathering (AW) tests have become a requirement for many wood composite products. This project monitored temperature and moisture content of specimens undergoing AW exposure for the following standards: ASTM D3434 (automatic boil test), CSA O112.9 (boil-dry-freeze), and PS2 (Section 7.17, 6-cycle VPS). Each AW procedure was conducted with three...
Wood-based composites (WBCs) are an important sector of the US economy. For a WBC product to succeed, understanding its long-term durability, including seasonal variations in temperature and humidity, is critical. Durability is especially important WBCs because they are predominantly made from wood, which is a biological, hygroscopic material that is...
Cross-laminated timber (CLT) is revolutionizing the use of wood in the construction sector of North America as a solution for walls and diaphragms in mid-rise or even high-rise timber structures on account of its environmental advantages, high strength-to-weight ratio, fire-safety performance, and propensity for prefabrication. However, considering the hygroscopic nature...
This paper discusses elementary, and secondary (K-12) teachers’ perceptions of cross-reality (XR) tools for data visualization and use of sensor data from the built environment in classroom curricula. Our objective was to explore the use of sensor-informed XR in the built environment and civil engineering (BECE) field to support K-12...
Timber-concrete composite (TCC) floors have improved strength and stiffness when compared to timber-only floors, allowing for longer spans in buildings and improved life safety. However, North America does not have codes and standards that recognize TCC floors, particularly the improved life safety performance of these floors in fire. Therefore, alternate...
Mass timber is emerging as a viable form of construction around the world in new markets for wood buildings. The entrance into these markets has driven the demand for more knowledge to enable designs alongside other structural materials such as steel and reinforced concrete.
Large, in-plane tests on cross-laminated timber...
Dimensional stability of wood-based composites with changing moisture content remains an important challenge in the industry for many applications. Wood modification technologies have shown significant improvement in dimensional stability by altering the chemistry of the wood substrate, or by filling the available space in the wood microstructure that otherwise would...
As mass-timber building construction rises around the globe, there exists the need to verify the long-term, in-situ behavior and performance of these structural systems. Structural health monitoring (SHM), generally defined as a damage detection strategy consisting of a network of sensors, a data acquisition system, and algorithms for data analysis,...
Although there are continuous efforts aimed at increasing gender diversity, the forest sector is still largely perceived as a male dominated field, indicated by a persistent masculine image. As a result, women are still underrepresented. Utilizing interviews, we found that greater representation of women in the forest sector is considered...
Using plant fibers as a potential renewable material to substitute for glass fibers in fiber-reinforced polymer composites has been growing since the late 1990s. Due to high demand, there has been a shift towards ‘green concept’ material in many applications. Numerous secondary plant fibers have been explored as a source...
Existing strategies and policies have emphasized the need for cross-sector collaboration as a means for the forest sector to be more competitive. Cross-sector collaboration initiatives of forest sector companies with neighboring industries such as energy, chemicals, plastics, textiles, and packaging are gaining increasing attention as a necessary element for a...
The United States generates over 70 million tonnes of wood waste annually, with over 27 million tonnes still available for recovery. Current recycling rates for wood waste are in the range of 10% to 15%, which is much lower than other common building materials and indicative of an underutilized resource....
In recent years, multiple historic and contemporary timber buildings have been instrumented with sensors to monitor the performance of wood products and novel engineering systems. While literature states the potential of structural health monitoring (SHM) data to inform decision-making process of key stakeholders in the architects, engineers, contractors and manufacturers...
Cross-laminated timber (CLT) panels have been gaining popularity as diaphragm elements in mid- to high-rise construction projects. In addition, CLT-concrete composite (CCC) diaphragms have been implemented to expand the use of CLT diaphragms. To understand the behavior of CLT and CCC diaphragms, this research effort sought to characterize the cyclic,...
Cross-Laminated Timber (CLT) is one of the latest engineered wood products to show promising structural features for a variety of structural purposes including resisting lateral loads. For CLT to be widely adopted, its modal behavior needs to be fully evaluated through experimental and numerical methods. It is important to the...
Wood plays a key role in modern electrical infrastructure; crossarms and power poles utilize the high strength to weight ratio, availability and low cost of wood to facilitate the access of power to millions of Americans. However, wood presents a variety of challenges as a material. In structural applications, one...
The global Cross-Laminated Timber (CLT) industry has changed dramatically within the past decade, with expansion outside of its start in Alpine Europe. The societal focus on more sustainable options within the built environment has led to an increased use of mass timber construction and its products including cross-laminated timber. Examining...
Timber engineering is currently in the midst of a significant evolution due to the rise of mass timber products, like cross-laminated timber (CLT). Increasing numbers of structural engineers are facing the challenge of designing lateral-force-resisting systems (LFRS) for multistory CLT structures. LFRS solutions such as steel frames, concrete cores, or...
Wood-based composites such as plywood and particleboard are produced with a thermoset adhesive via a hot-press process. At present, UF is the most commonly used thermoset adhesive for production of decorative plywood. The emission of the carcinogenic formaldehyde from UF-bonded panels during the use of panels affects the indoor air...
Fungi from the genus Chlorociboria are known for their production of the blue-green quinonic pigment xylindein. Extracted xylindein has been the subject of investigations ranging from fabric dying to use a coloring agent in paint, and shows potential as an organic semiconductor in organic photovoltaics (OPVs) and other technologies. However,...
Connections in mass timber structural systems dissipate energy and transfer lateral forces from mass timber elements such as shear walls and diaphragms, providing critical load paths. Cross-laminated timber (CLT) is a prominent mass timber material used to manufacture wall and floor assemblies. Fire performance research of CLT walls and floors...
The sustainable use of wood for rail ties requires chemical treatment to increase service life and maintain structural integrity. Treatment can only be applied after lengthy air-seasoning to reduce moisture content in wood, but seasoning leaves ties exposed to attack by decay fungi for up to a year. One factor...
The objective of this study was to investigate load paths in an existing light-frame wood structure with complex geometry, using previously established computer modeling methods. The structural model is derived from an existing, multi-level residence located in Corvallis, Oregon. For the purpose of this study, the existing structure was simplified...
Natural dyes have been used to color textiles for centuries, but with the shift to mass production, the use of synthetic dyes has increased due to their lower cost and easy manufacturing volume. However, synthetic dyes (such as disperse blue dyes 106 and 124) have been reported to cause skin...
Cross-Laminated Timber (CLT) is a prefabricated building material that is relatively new to the United States and North America. It consists of no less than three layers of graded, dimensional lumber glued in alternating longitudinal and transverse layers to create a panel that can be used for various building applications...
Natural durability remains one of the most attractive characteristics of wood, and helps wood obtain a premium price. A worldwide shift towards the use of younger trees from intensively managed forests has created greater concerns about wood quality, especially the wood’s resistance to fungi and insects. Wood durability is assessed...
The majority of low-rise residential structures in the U.S. are constructed with wood. Wood-based composites are primary building materials in these structures, used as structural sheathing, joists, and beam components. Wood composites are susceptible to degradation upon exposure to high levels of moisture. Moisture durability is routinely assessed with accelerated...
Cross laminated timber (CLT) is a relatively new engineered wood product that has elevated the prospects of utilizing wood as the primary structural material for mid and high rise buildings. The hygrothermal performance of CLT, however, is still not well understood at the material, assembly and building scales. A major...
In the last few decades new trends and innovations in wood products have emerged that are changing the way we can use this material in buildings. Additionally, wood is a material that has been touted to have many positive attributes in comparison to nonrenewable construction materials such as steel and...
Wood-staining fungal pigments have potential uses as colorants for wood and textiles. Traditionally, organic solvents have been used as carriers for these pigments. However, other environmentally-friendly and more readily available carriers must be found. Natural oils have the potential to carry these pigments but have demonstrated color loss over relatively...
Small hairline cracks called checks in the decorative face veneer of hardwood plywood are a costly problem for the hardwood plywood industry. Hardwood plywood describes any plywood sheet with a hardwood face veneer glued onto a core substrate. Checks form due to differential shrinkage stresses. Not all hardwood plywood panels...
There is a lack of fundamental knowledge about the role which adhesive flow and infiltration plays in the micro-mechanical performance of wood adhesive bonds. This data set, for the first time, provides a way to study directly the relationship between adhesive flow and the micro-mechanics of wood adhesive bonds.
Specimens...