With the resurgence in the interest of using natural textile dyes, a solution must be found that will overcome the limitations of traditional natural dyes. This solution must also be safer for both humankind and the environment than are synthetic dyes. This study compares the colorfastness of commercially available synthetic...
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,...
The context of this thesis is a research project focused on the investigation of a renewable biopolymer-poly(lactic acid) (PLA) as a potential replacement of petroleum-based polymers in advanced nanocomposites reinforced with Microfibrillated cellulose (MFC). MFC is extracted from wood, which is a renewable, sustainable, carbon neutral and recyclable material. This...
The wood-based building products industry has experienced significant turbulence over the past several decades as a function of multiple forces including among others globalization, product and process innovation, and shifting customer and consumer interest and demands. Collectively, these changes have challenged the historical tenets which have defined industry strategy and...
The essential oil components of cedar heartwoods play an important role in the durability of these trees. Yet, the composition of these oils and identity of many of the compounds remains unknown, or incompletely know for some commercially important cedar heartwoods. The essential oil extracts of Alaska Yellow Cedar (Chamaecyparis...
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...
This research studied the effects of changing from a traditional manufacturing
system to a cell manufacturing system in a value-added wood products company.
Discrete event simulation was used to describe the current system and the proposed
new systems. Parts were separated into part families that shared similar processing
requirements. From...
While microbial colonization of wood is presumed to be characterized by a myriad of interactions between numerous organisms, studying these processes is often difficult owing to the opaque nature of the wood and the inability to readily distinguish among the many species colonizing the material. One method for enhancing the...
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...
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...
In the residential sector, wood is the predominant construction material. In the commercial sector and in mid‐rise construction, the use of wood is limited because of a multitude of reasons, including building code restrictions, the perception of wood as a structural material, fire code requirements, and lack of knowledge and...
The goal of this study was to develop an understanding of the nature of surge wave loading on
wood framed residential structures for a variety of building configurations and test conditions.
The objectives of the study were: (1) to measure forces on a 1/6th scale wood framed
residential structure, (2)...
The goal of this project is to contribute to the development of design values for cross-laminated timber (CLT) diaphragms in the seismic load-resisting system for buildings. Monotonic and cyclic tests to determine strength and stiffness characteristics of 2.44 m (8 ft) long shear connections with common self-tapping screws were performed....
The fundamental intent of the study was to develop an innovative wood-strand composite for use in structural applications. Plantation grown, low density, hybrid poplar was used in the study which was found to be appropriate for the underlying Viscoelastic Thermal Compression (VTC) process. Wood modified by this process has high...
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...
Microchannel devices are rapidly evolving process technology with a wide variety of applications. Microchannel devices hold the potential to transform many separation processes. One potential application for such microchannel devices is kidney dialysis. By reducing the size and cost of the device, this technology offers the potential to allow dialysis...
Fungi are the primary biological agents of wood deterioration and cause major economic losses of wood products globally. Wood in outdoor applications tends to remain wet for extended time periods, making it susceptible to fungal attack. Understanding the factors involved in fungal colonization of wood is important for developing improved...
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...
The mechanical performance of composite materials is determined by the mechanical properties of their individual components and the effective load transfer between these components. Binders are commonly used to bond composite components together and to provide effective load transfer between them. In wood-based composites the binder-component load transfer occurs at...
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...
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...
The tendency of wood to shrink and swell with changing moisture content remains as one of the most significant challenges to using wood in its many applications. Viscoelastic Thermal Compression (VTC) has been shown to significantly increase the density, strength and stiffness of wood. However, dimensional stability is still a...
The increasing demand for forest products and restricted use of natural forests has resulted in a shortage of high-strength wood fiber. The area covered by plantation forests is steadily rising, but the fiber produced by these forests is often unsuitable for high-strength applications. One attempt to combat this problem is...
Many publications, documents, codes and guidelines exist related to the seismic evaluation and rehabilitation design of existing buildings. This report discusses the assumptions and methods employed for investigation of two wood structures using four references: FEMA 154, FEMA 356, ASCEI per SEI 31, and 1997 UBC. The screening performed using...
When Douglas-fir and red alder grow in mixture, interactions between the two species can be competitive, facilitative, or a combination of both over time. A number of factors have recently led to increased interest in managing these two species together for commercial production, and ongoing investigations are yielding important information...
The importance of wood bonding increased in the last decades due to the
increased usage of wood composites whose performance depends to a large extent on
the adhesive penetration and subsequent bonding of the adherends. The presented
research used XMT (x-ray microtomography) to perform a non-destructive, threedimensional
analysis of the...
The effects of incorporation of selected biocides on physical and mechanical properties of aspen strandboard were assessed using five copper-based preservatives or zinc borate at three retention levels. Tebuconazole or 4,5-dichloro-2-N-octyl-4-isothiazolin-3-one (DCOI) were added as co-biocides to selective copper-based treatments. Mold box tests showed that only panels treated with DCOI...
Corporate social responsibility (CSR) can be defined as companies acting in accordance with societal demands. In recent years, CSR has gradually become a leading issue in business. Heightened corporate attention to CSR has not been entirely voluntary. Many companies awoke to it only after being surprised by public response to...
Business is a social institution and society has always designated a role for
business which has been undergoing changes with changing societal values and
paradigms. Thus while business has always had some responsibilities, the modern
connotation of the words corporate social responsibility commonly refers to business
assuming responsibilities in economic,...
The development of cross-laminated timber (CLT) panel technology has opened up new opportunities for wood in tall buildings. Several characteristics including seismic performance and speed of construction have raised interest among designers. As CLT gains acceptance in the industry, alternative structural solutions need to be investigated to improve performance of...
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...
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...
One of the recent additions to the panoply of engineered wood products is cross-laminated timber (CLT). CLT is a prefabricated, large-scale, solid wood panel that consists of multiple layers of lumbers stacked together, with each layer arranged perpendicular to the next layer, glued with structural grade adhesives, and pressed. The...
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...
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...
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...
As oriented strand board (OSB) increases in use as an engineered wood product, improving the in-plane shear properties will allow more efficient use of the material as well as open up other opportunities for OSB to be used in engineered wood products with high shear stresses. Based on classical laminated...
The purpose of this thesis was to evaluate orthogonal cutting as a method to determine the fracture toughness of low and high density polyethylene and wood plastic composites. A test fixture was developed to capture normal and tangential cutting forces at variable depth and rake angle. A tool interface method...
Untreated wood is inherently hygroscopic and moisture content variations can have substantial effects on dimensional stability leading to the development of deep surface checks that further enhance moisture uptake and ultimately encourage deterioration. The horizontal exposure of wood crossties makes water repellency and dimensional stability particularly important in railroad applications....
Today nano scale materials are being used for wide range of applications. One promising topic in nano scale materials is using them for reinforcement of different polymeric materials to reach desirable stiffness properties. The stiffness of these materials is mostly found experimentally because the nanocomposite community lacks a decent analytical...
Formaldehyde-based adhesives such as urea-formaldehyde (UF) and phenol-formaldehyde (PF) adhesives dominate the current wood adhesive market. However, these adhesives are derived from petrochemicals and carcinogenic formaldehyde. In this study, we developed two formaldehyde-free adhesives based on abundant, renewable, and inexpensive soy flour (SF).
The first adhesive was mainly composed of...
Synthetic adhesives, such as phenol-formaldehyde (PF) resins and urea-formaldehyde (UF) resins, have dominated the wood adhesive market since they were introduced in the wood products industry. Formaldehyde, as a key component in the manufacturing of PF and UF resins, has been classified as a known human carcinogen by the International...
Natural fibers are gaining popularity as reinforcement materials for thermoset resins over the last two decades. Natural fibers are inexpensive, abundant, renewable and environmentally friendly. Kenaf fibers are one of the natural fibers that can potentially be used for reinforcing unsaturated polyester (UPE). As a polymer matrix, UPE enjoys a...
Synthetic adhesives like phenol formaldehyde (PF) and isocyanates dominate the
wood based structural panel market. The raw materials that makeup these adhesives
are based on petroleum and natural gas. The sustainability and the continued success
of the wood based structural panel industry will benefit from the development of
alternative adhesives...
Resistance to moisture uptake is an important attribute of some wood preservatives and can help reduce moisture cycling that leads to the development of deep checks. While the potential for preservative treatments to help improve wood/moisture interactions is acknowledged, there are no tests that specifically evaluate this performance parameter. Checking...
This study examined the decay resistance of the pine and maple components of wood plastic composites (WPC' s) of varying thicknesses exposed on several culture media to wood decay fungi under laboratory conditions. The ability of malt agar extract (MEA), potato dextrose agar (PDA), amended basal salts, sawdust (maple and...
Wood adhesives are essential components of wood composites. At
present, the commonly used wood adhesives, phenol-formaldehyde (PF)
and urea-formaldehyde (UF) resins, are petroleum-based synthetic resins
that may result in emission of formaldehyde in the production and use of
wood composites. Because the world's oil reserves are naturally limited
and formaldehyde...
During the past several decades, earthquakes have caused extensive damage to
buildings, including wood-frame, single-family dwellings, in the United States. In
order to mitigate future losses, existing buildings in earthquake prone areas should be
evaluated for their seismic safety. This is also an important issue for buildings in
Oregon due...
Polymeric composites reinforced with bio-materials have advantages over composites with synthetic reinforcements. Bio-based composites use low-cost and renewable reinforcements, have nonabrasive properties for machining, have improved damping characteristics, and have potential for energy recycling. However, the limited use of bio-based composites is because their mechanical properties are typically much lower...
The fabrication of nano-scale devices is a challenging, but potentially important, technology that has drawn a great deal of interest among researchers. Such nanoscale constructions utilizing a bottom-up approach for device building have many foreseeable applications in areas as diverse as miniaturized electronics, sensors, and biomedical devices.
One of the...