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 dynamics of radio frequency (RF) laminated veneer lumber (LVL) pressing are explored for the purpose of optimizing this process. The RF LVL press at the Albany Trus Joist plant is the focus of this investigation. The investigation first focuses on bond strength development characteristics of the Georgia Pacific adhesive...
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...
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...
High density polyethylene (HDPE) is a ubiquitous material with versatile properties. It is produced and used in greater volume than any other thermoplastic. HDPE is often filled with a variety of materials for various applications. Glass fiber and wood flour are two common fillers for HDPE. Recently there has been...
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...
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...
Current compression perpendicular-to-grain (c-perp) design values for wood members are based on mean stress using the ASTM D143 specimen. Base design value, as determined from 0.04-in deformation in the ASTM specimen, is applied to all c-perp applications. While the standard ASTM test was presumably believed to adequately reflect relevant c-perp...
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...
Wood remains the most popular material for deck construction. For centuries, consumers have chosen wood because of its desirable qualities and aesthetics. In recent years, wood plastic composites (WPC's) have seen rising demand as alternatives to wood decks, despite a large price premium. In addition, the removal of CCA treated...
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...
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...
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....
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...
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...
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...
Many paper products like towel and tissue cannot serve their purposes without temporary wet strength Glyoxal-polyacrylamide (GPA) resin is one of the widely used commercial wet strength additives that impart the temporary wet strength to paper and paperboard products However, GPA resin is derived from petrochemicals and contributes to contaminants...
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...
This study investigated variation in xylem anatomy, hydraulic properties, and the relationship between anatomy and properties within Douglas-fir trees at multiple scales. The hierarchical scales in the study included fertilization treatments (fertilized and unfertilized), trees within the treatments, and positions within the trees. Tracheid diameter, tracheid length, percent latewood, number...
Architects and engineers are two key types of design professionals who influence the use of wood products in construction. Eighty to ninety percent by volume of all residential structures in the U.S. are wood (Gupta, 2005). In 2010, the non-residential market was made up by 10% wood, 60% steel and...
There are over 130 million wood poles supporting electrical transmission and distribution lines in the U.S. The vast majority of these poles are preservative treated to prolong their useful life. In some cases, however, the depth of treatment is relatively shallow, leaving a deep zone of moderately durable, untreated heartwood....
Cross-laminated timber (CLT) is a massive engineered wood product made of orthogonally bonded layers of solid-sawn lumber, and is intended for roof, floor, or wall applications. Although it was developed in Europe in the early 90s, CLT is relatively new to North America.
CLT products must be certified for structural...
Copper is the most common ingredient in waterborne preservatives and provides excellent activity against most fungi and insects. However, issues associated with copper migration from treated wood have created increasing concerns about potential risks to non-target organisms in surrounding environments, especially those in sensitive aquatic environments. Various Best Management Practices...
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...
The objectives of this study are: (1) to evaluate the effect of reference
displacement on wall behavior under fully reversed cyclic loading using the
CUREE test protocol and (2) to assess damage accumulation (visible fastener
damage and stiffness degradation) for the imposed drift levels. All tests were
conducted on identical...
Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), a shade intolerant species, and western hemlock (Tsuga heterophylla (Raf.) Sarg.), a shade tolerant species, were compared to learn more about the temporal pattern of release from suppression in both species, whether hydraulic architecture or photosynthetic capacity constrain release and how wood functional properties change...
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...
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...
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...
Western juniper and cinnamon essential oils were combined with ethanol at 2.5, 5, and 10% concentrations by weight and applied to hybrid poplar (Populus trichocarpa x P. deltoids) veneers by vacuum soaking to produce a naturally durable wood veneer with increased mechanical properties for use in structural composites. Half of...
The goal of this study was to optimize a through-boring pattern that will provide adequate preservative penetration while minimizing the reduction in overall pole bending strength. Hole spacing was developed using longitudinal and transverse chemical penetration data from previous studies. Finite element analysis was used as a preliminary assessment tool...
Western juniper (Juniperus occidentalis) is a conifer that is native to Oregon, California, Washington, Nevada, and Idaho. Juniper is known to have highly decay resistant heartwood and is a popular choice for finished furniture. With recent forest management practices over the past 100 years have resulted in an immense population...