Flexible pavements consist of multilayers, which form the pavement structures. Since the strength of the bond at interface between layers plays a significant role in improving the structural integri-ty and the performance of pavement structures, tack coat materials and methods used for their application during construction are important in providing...
The Self-indicating Instant Radiation Dosimeter (SIRAD) is credit card size, self reading, single use dosimeter produced by JP Laboratories. The SIRAD has a chemical strip that changes color based upon incident radiation. The color change is instantaneous and cumulative. The card was designed for first responders as a way for...
The Self-indicating Instant Radiation Alert Dosimeter, SIRAD™,
manufactured by JP Labs*, is a dosimeter that can be used by emergency response
persoimel. It is a user-friendly, inexpensive, and disposable radiation dosimeter. It
monitors high doses, 5-200 rads, of ionizing radiation. The card resembles the size of a
credit card and...
The merits of the photoelastic coating technique as applied to
wood were evaluated. Comparative tests were made on 12 nominal
two-by-four Douglas Fir boards. The object of these tests was to
determine the limitations of this technique, such as accuracy and
complexity of experimental procedure. Correlation of the experimental
results...
Biaxial strength characteristics of wood-based structural panels were evaluated by
using analytical and experimental methods. Cruciform plywood specimens were tested
under biaxial tensile-tensile, compressive-compressive loadings in a symmetrically-jointed-
arm test fixture, which was mounted on a universal testing machine. Performance
of the test fixture was also evaluated during the tests....
Woody biomass transportation costs and market values/costs are strongly correlated with the woody biomass moisture content. Properly managing moisture content can potentially lead to economic and environmental advantages in biomass energy markets. Good management requires accurate moisture content measurements. Therefore, availability of accurate, precise, reliable, and efficient tools to assess...
The Pacific Coast variety of Douglas-fir was investigated.
The samples were tested using both forced and free vibrations. Transverse
vibrations were introduced by excitations on the side of the
samples. Forced vibrations were applied from 5000 to 0 hertz by a
vibration generator, and free vibrations were initiated by a...
Efficient use of wood in structural applications depends
upon the accuracy with which we can predict the mechanical
behavior of members under load. Most methods of lumber grading
and laminated beam design depend upon statistical and/or
empirical techniques in which averaged properties for complete
members are derived. A knowledge of...
The objectives of this study were to 1) develop a relatively quick staining procedure that would detect incipient decay by color differentiation under fluorescence, 2) quantitatively assess the amount of decay present with the use of an image analyzer, and 3) re/ate loss in strength at various decay levels to...
Three samples of different wood densities of Douglas-fir
(Pseudotsuga menziesii (Mirb.) Franco) were cooked by
the kraft process. The yields and the Kappa numbers were
studied to establish the rates and the energies of activation
of the pulping and delignification reactions
respectively. Wood properties did not show significant
effects on...
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...
Douglas-fir utility poles are routinely air seasoned before
treatment with chemical preservatives. Basidiomycetous fungi invade
these poles and may cause strength loss during air seasoning or later
if treatment temperatures are insufficient to kill the decay fungi.
The purpose of this study was to develop a rapid test to asses...
A novel, low-cost instrument capable of measuring surface water PCO₂ was designed for use in dynamic, shallow-water environments. The instrument was tested in the Yaquina River Estuary, a macrotidal estuary known to experience a wide range of conditions ranging from dominance by the coastal ocean during summer upwelling to substantial...
In Radio Frequency Integrated Circuits (RFIC) or high frequency digital
ICs, there is a demand to probe the internal nodes for testing. The ultra low
capacitance RFIC probe presented in his work is a flexible tool for these
applications. The probe utilizes the coupling between a tungsten needle and the...
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...
New species introductions have been associated with the movement of
people for thousands of years. For instance, horses were introduced into North
America by Spanish explorers, while pigs were introduced by the Polynesians
into many Pacific islands long before the establishment of permanent
European settlements. Both of these species introductions...
Moisture durability is essential for wood composites, especially those used in building construction, where products are prone to weathering. The primary focus of this research was to determine if adhesive penetration into the cell wall has a positive influence on adhesive bond durability. To fully understand the measureable effects of...
This project determines the short term and long term effective stiffness values for Cross Laminated Timber (CLT) with a reinforced concrete topping. The reinforced concrete was attached to the CLT panels with interface connections, and different types of interface connections were tested. Throughout this project, there are 31 tests with...
Oriented strand board is a panel product used in
structural applications in home construction much like
plywood, yet little is known of the effect of temperature and
moisture content on its performance. The objective of this
study is to study these effects on oriented strand board and
for comparative purposes...
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...
Heartwood samples of Pacific Coastal Douglas-fir (Pseudotsuga
menziesii var. menziesii) and Rocky Mountain Douglas-fir
(Pseudotsuga menziesii var. glauca) were rated for relative liquid
permeability, and evaluated for kraft pulping characteristics.
Highly impermeable wood of the Rocky Mountain variety was termed
"refractory," while the pervious wood of the Pacific Coastal variety...
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...
Commercial methodologies for producing fungal pigments are of worldwide interest due to the desire to move away from synthetic dyes. Chlorociboria species and Scytalidium species have been reported to produce sufficient yields of pigments for commercial production and have attracted special attention because of their use in spalted wood applications....
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 overall goal of this study was to evaluate an alternative to
traditional wood framed shear wall construction. This study introduced the
innovative idea of using a water and seismic damage resistant, wood-concrete-
composite (WCC) construction instead of an all-wood design. The
WCC design consisted of a thin shell of...
Concerns over the possibility of exotic pest
introductions from eastern Russia to the West Coast of the United States due to proposed log imports raises the question of the effectiveness of possible mitigation measures. Toxicity of methyl bromide to representative pathogenic fungi was tested by exposing Armillaria ostoyae, Heterobasidion annosum,...
Ultrasonic wave attenuation and velocity in the transverse direction were used to detect defects in ponderosa pine (Pinus Ponderosa) lumber previously dried from green to 9% moisture content. After ultrasonic testing the boards were visually inspected for defects and classified according to the defects present. An ANOVA with Bonferroni pairwise...
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...
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...
