Oriented Strand Board Research Articles

Experimental Investigation of the Flammable Properties and Factors of Wooden Products Exposed to the Fire Impact

Consideration was given to the issue of the integrated evaluation of the flammable properties and factors of wooden products (Oriented Strand Boards, OSB and Wood Particle Boards, WPB) as basic flammable construction materials exposed to the action of fire. The experimental data obtained for flammable wooden products during the experiments carried out to define the dependence of temperature on the time of fire impact, to measure and substantiate the charring depth of wooden products, to determine degradation zones affected by fire and their sizes (area, width and length) and to compare a change in the specimen mass before and after the tests have been given. The experimental data confirm and substantiate the pyrolysis processes of wooden products during the fire spread.

A new strategy for bamboo ultra-long radial slice preparation and novel composite fabrication

Bamboo has high-mechanical-strength fibers arranged longitudinally in its growth direction. However, its hollow structure has nodes and uneven density walls, which complicate bamboo processing and utilization. In this study, a method for preparing bamboo ultra-long radial slices (BURSs) along the bamboo growth direction and using the corollary equipment was proposed. New BURSs with a curling shape were collected regularly and weighed to be approximately the same. Several groups of BURSs with the same quality were regularly arranged and pressed into BURS composites (BURSCs) with density of 0.5, 0.6, 0.7 or 0.8 g/cm3. The BURSs well retained fiber integrity. The BURSC with density of 0.7 g/cm3 showed a higher strength-to-density ratio (S: D) than wooden oriented strand board (OSB). Its modulus of rupture, modulus of elasticity, internal bond strength and thickness swelling were 47.5 MPa, 3723 MPa, 1.03 MPa and 3.61%, respectively. Furthermore, a novel BURS processing mode which was optimized into bamboo medial slices with thin edge and green strips with triangular cross-section was proposed. Drum-shaped cross-section with thinner edge improved flowability of bamboo slices during hot pressing and optimized the structure of the composites. This BURS was a novel high-quality component of bamboo boards with high surface quality, strip strength, efficient producing and easy assembling of bamboo strands. The BURSC was proved to be an upgrade product of bamboo OSB and bamboo plywood with high S: D, excellent surface quality and high utilization rate of bamboo.

Fabrication of structurally graded material (pure PLA/WFPC): Mechanical and microscopic aspects

The aim of this study is to provide first-hand knowledge on additively manufactured structurally graded material (SGM) (polylactic acid / wood-fiber polymer composites) wall. Polylactic acid or polylactide is most effectively used in manufacturing plastic films, bottles, biodegradable medical devices, textile, and agricultural goods. Wood-fiber polymer composites are essentially used in furniture, particleboard, oriented strand board, medium-density fibreboard, plywood, and constructions. SGM is characterized through the change in material composition that is applicable to specific functions. Fabricated SGM exhibited mechanical property such as tensile strength (15.78 ± 0.05 MPa), compressive strength (46.8 ± 2.7 MPa), flexural strength (88.2 ± 0.15 MPa), and impact energy (1.64 ± 0.07 J). Hardness value of SGM is 74.5 shore-D. The coupon studies revealed that SGM possesses better mechanical characteristics than wood-fiber polymer composites and is on par with polylactic acid. The observed morphologies on fracture surface indicate the brittle nature of fracture. This SGM come under advanced materials that are utilized in biomedical, defence, energy, aviation, and nuclear sector, for integrated structural and thermal application.

Mechanical properties of structural particleboard and termite and decay resistance

The mechanical properties and termite and decay resistance performance of wood-based panel used in wooden houses were evaluated. The physical and mechanical properties, along with the resistance levels, of commonly used wood-based panels, including oriented strand board, structural particleboard, and particleboard for use in interior, were compared. The structural particleboard complied with the physical, mechanical, and formaldehyde emission standards of the International Organization for Standardization and Japanese Industrial Standard, surpassing the requirements for oriented strand board. The structural particleboard exhibited excellent water resistance and a consistent performance. Decay tests classified the particleboard and structural particleboard as “Resistant,” with mass losses of 7.82 to 12.72% (white rot) and 14.69 to 16.55% (brown rot). Pine (Pinus densiflora) and oriented strand board exhibited no decay resistance, with mass losses exceeding 45%. The particleboard and structural particleboard demonstrated superior termite resistance, resulting in 100% termite mortality in three days without chemical treatment. The structural particleboard exhibited excellent water, decay, and termite resistance, which can be an advantage in wooden-house construction in terms of maintenance.

Exposure Risks and Potential Control Measures for a Fire Behavior Lab Training Structure: Part B—Chemical Gas Concentrations

Firefighters’ or instructors’ exposure to airborne chemicals during live-fire training may depend on fuels being burned, fuel orientation and participants’ location within the structure. This study was designed to evaluate the impact of different control measures on exposure risk to combustion byproducts during fire dynamics training where fuel packages are mounted at or near the ceiling. These measures included substitution of training fuels (low density wood fiberboard, oriented strand board (OSB), pallets, particle board, plywood) and adoption of engineering controls such as changing the location of the instructor and students using the structure. Experiments were conducted for two different training durations: the typical six ventilation cycle (six-cycle) and a shorter three ventilation cycle (three-cycle) with a subset of training fuels. In Part A of this series, we characterized the fire dynamics within the structure, including the ability of each fuel to provide an environment that achieves the training objectives. Here, in Part B, airborne chemical concentrations are reported at the location where fire instructors would typically be operating. We hypothesized that utilizing a training fuel package with solid wood pallets would result in lower concentrations of airborne contaminants at the rear instructor location than wood-based sheet products containing additional resins and/or waxes. In the six-cycle experiments (at the rear instructor location), OSB-fueled fires produced the highest median concentrations of benzene and 1,3 butadiene, plywood-fueled fires produced the highest total polycyclic aromatic hydrocarbon (PAH) concentrations, particle board-fueled fires produced the highest methyl isocyanate concentrations, and pallet-fueled fires produced the highest hydrogen chloride concentrations. All fuels other than particle board produced similarly high levels of formaldehyde at the rear instructor location. The OSB fuel package created the most consistent fire dynamics over six-cycles, while fiberboard resulted in consistent fire dynamics only for the first three cycles. In the follow-on three-cycle experiment, PAH, benzene, and aldehyde concentrations were similar for the OSB and fiberboard-fueled fires. Air sampling did not identify any clear differences between training fires from burning solid wood pallets and those that incorporate wood-based sheet products for this commonly employed fuel arrangement with fuels mounted high in the compartment. However, it was found that exposure can be reduced by moving firefighters and instructors lower in the compartment and/or by moving the instructor in charge of ventilation from the rear of the structure (where highest concentrations were consistently measured) to an outside position.

Effect of pretreatment and compaction ratio on the properties of oriented strand board from sengon (Paraserianthes falcataria L. Nielsen) wood

ABSTRACT Low-density wood produces composites with low dimensional stability, requiring a high compaction ratio (CR) to produce an oriented strand board (OSB). This study evaluates the physical and mechanical properties of the OSB prepared from low-density wood, i.e. sengon (Paraserianthes falcataria L. Nielsen), under steam modification and various CRs. The wood strands were steamed at 126°C under 0.14 MPa pressure for an hour and then washed with 1% sodium hydroxide for 30 sec. Three-layered OSBs with a shelling ratio (face-to-core layers ratio) of 1:2:1 were manufactured using 10% resin content of phenol formaldehyde. Panels with three different strand pretreatments and five levels of CR were evaluated. The results show that there is an improvement in the bonding between the strand and the resin with steam and the steam followed by washing with 1% NaOH pretreatments. Both pretreatments of strands significantly improved the dimensional stability of obtained OSB but did not affect the mechanical properties. The physical and mechanical properties of OSB improved by the increased CR. The OSBs with a CR of 1.58 has the best physical and mechanical properties.

Flexural Behavior of Built-Up Cold-formed Steel Channel Section Strengthened with Oriented Strand Board

The objective of the study is to determine the flexural behavior of the built-up cold-formed steel (CFS) channel section strengthened with an oriented strand board (OSB) in the three-point bending experiment. CFS with a variety of shapes and grades is classified as a steel-based material and exposed to buckling failure when subjected to compression or flexural load. Thus, the CFS channel section with 100 mm of the web, 50 mm of the flange, 12 mm of the lip, and 1.55 mm of thickness has been selected. Then, the built-up CFS channel section is designed by filling with an OSB between the gap of each section. Channel, face-to-face built-up, and back-to-back built-up CFS sections are three types of tested specimens. From the result and discussion, the specimen with back-to-back built-up CFS section is recognized to sustain the ultimate load with the highest value when compared with other specimens.

Mechanical Properties of the Oriented Strand Board (OSB) Distributed in the Korean Market

Mechanical Properties of the Oriented Strand Board (OSB) Distributed in the Korean Market

Effects of air-plasma treatment in enhancing the mechanical properties of oriented strand boards

In this work, through surface modification of poplar strands with a non-thermal type of plasma, we produced oriented strand board (OSB) panels with high loading capacity (fabricated with a target density of 0.7 g/cm3 and phenol-formaldehyde resin in a content of 7%). At the processing power of 4.5 kW, the plasma-induced efficient etching effect and chemical grafting contributed greatly to improving the wettability of strands surfaces, resulting in the 68.3% increase of resin coverage and the formation of consecutive bond-lines within the structures of OSB. Furthermore, the adhesive distribution within wood surface layers and adhesion efficiency were intensively analyzed by means of X-ray computed tomography imaging, the results demonstrated that the plasma-based surface modification considerably increased the penetration depth of the resin into the wood volume, making it easier to form mechanical interlocking in wood-resin interphase. Further nanoindentation analysis on the resin-infiltrated cell walls revealed the substantial reinforcement of bonding interphase after plasma modification. In bonding performance tests, the internal bond strength of plasma-modified OSB reached up to 1.22 MPa, nearly 3.6 times the value recommended by ISO 16894: OSB panels type 4. Meanwhile, the loadbearing property was improved significantly, which was not only reflected in the enhanced bending strength and elastic modulus, but was also confirmed by strain distribution along the thickness direction recorded using digital image correlation technique.

Investigating the Effects of Al2O3 Microparticles on Wood Waste OSBs: A Study on Physical, Mechanical, and Durability Performance.

The development of new materials for the construction sector is a global trend, and products that use by-products in their composition and have also incorporated technology are commercially competitive. Microparticles have large surface areas and can modify the microstructure of materials, positively affecting their physical and mechanical properties. In this context, this study aims to investigate the effect of incorporating aluminium oxide (Al2O3) microparticles on the physical and mechanical properties of oriented strand boards (OSBs) made from reforested residual balsa and castor oil polyurethane resin and to evaluate their durability performance under accelerated aging conditions. The OSBs were produced on a laboratory scale with a density of 650 kg/m3, strand-type particles measuring 90 × 25 × 1 mm3, using castor oil-based polyurethane resin (13%) and Al2O3 microparticle content ranging from 1% to 3% of the resin mass. The physical and mechanical properties of the OSBs were determined following the EN-300:2002 recommendations. The results obtained indicated that the OSBs with 2% Al2O3 presented thickness swelling significantly lower (at the 5% significance level) after being subjected to accelerated aging and internal bonding of the particles higher than the values obtained for the references, evidencing the positive effect of including Al2O3 microparticles in balsa OSBs.

Comparison on greenhouse gas footprint of three types of oriented strand board manufacturing process in China.

The greenhouse gas (GHG) footprints of oriented strand boards (OSB) have been gaining growing concern. China is one of the largest manufacturers and traders of OSB in the world. However, little data are available concerning the GHG footprint of Chinese OSB production. The purpose of this study is to quantify and compare the GHG footprints of three types of OSB produced in China. Cradle-to-gate GHG footprints assessment models were built for OSB according to PAS 2050 guidelines. The results showed that the cradle-to-gate GHG footprints of OSB/2, OSB/3, and OSB/4 were 142.7 kg CO2 e/m3, 173.2 kg CO2 e/m3, and 374.2 kg CO2 e/m3, respectively. Raw material acquisition was the largest contributor to GHG footprint for three types of OSB (52.6~57.6%), followed by the production process of OSB (25.6~27.3%) and transportation (15.3~20.1%). The consumption of wood, MDI, electricity, and the transportation of wood were main emission hotspots in Chinese OSB production. Ultimately, four feasible GHG emission reduction measures were put forward from the perspective of reducing the usage of wood and MDI adhesive, decreasing the electricity consumption, and shortening the transport distance of wood.

Exposure Risks and Potential Control Measures for a Fire Behavior Lab Training Structure: Part A—Fire Dynamics and Thermal Risk

National Fire Protection Association standard 1403 provides the fire service with guidance for conducting effective live fire training with the goal of minimizing health and safety hazards. The document provides guidelines for materials to be included in the training fuel package, but the fire service has raised questions about the use of specific types of wood products for this purpose. In this study, the fire dynamics generated when utilizing five different Class A materials that have been historically employed as training fuels [low density wood fiberboard, oriented strand board (OSB), pallets, particle board, plywood] in a single compartment fire training structure (Fire Behavior Lab) were characterized. A specific focus was placed on understanding the thermal and visual environment created for firefighters located at typical locations for instructors (front and rear of structure) and students (middle of the structure). The pallet fuel package required the longest time to transition through the six ventilation cycles while the OSB fuel package was the quickest. Additionally, the most consistent fire dynamics were demonstrated with the OSB fuel followed by particle board and plywood, while fiberboard and pallets resulted in less repeatable flashover or rollover demonstration. The OSB fuel package resulted in the highest peak heat fluxes and pallets resulted in the lowest. The most severe exposures were measured at the front instructor location. To control thermal risks when conducting training in the Fire Behavior Lab structure, instructors and students should orient themselves as low as possible in the observation area and behind the interior baffle when possible. Considering the high radiant exposures for the front instructor location, providing a local shield and reducing the time in the training structure can also reduce risk for thermal injury or personal protective equipment damage. Overall, different fuels can impact thermal exposures to firefighters, but varying fuels also affects the consistency of the fire dynamics being presented to the firefighting students.

Oriented Strand Board panels of residual reforestation wood with Al2O3 nanoparticles

The application of metal oxide nanoparticles (Al2O3) in Oriented Strand Board (OSB) panels has been studied as a way to provide greater efficiency in heat transfer rate during the thermopressing process, thus contributing to the polymerization process of the resin used in particle agglomeration. Studies on the subject, however, are still scarce and require further study in order to optimize the production process of OSB panels. Therefore, this study evaluated medium density OSB panels (650 kg/m3) of reforestation residual wood shaped with 13% castor oil-based polyurethane resin with 1% of commercially sourced Al2O3 nanoparticles and manufactured in the laboratory via the proteic sol-gel method. Microstructural analysis of the nanoparticles was performed to verify their dispersion within the resin; qualitative analysis of nanoparticles was performed with X-ray diffraction (XRD); and analysis by High Resolution Transmission Electron Microscopy (HRTEM) was performed to study commercially sourced and laboratory-produced nanoparticles. After analyzing the results, the panels were produced with commercial aluminum oxide nanoparticles and characterized by physical (thickness swelling) and mechanical (static bending and perpendicular traction) tests, according to current normative documents. The results indicated that commercial aluminum oxide nanoparticles provided better performance in microstructural and qualitative analysis, in addition to provide a better efficiency in the resin curing stage, causing an increase in the values of physical-mechanical properties in the transverse direction for the modulus of rupture (69.15%) and internal bond of the wood particles (53.57%).

СОРБЦИОННАЯ ВЛАЖНОСТЬ КОМПОЗИТНЫХ МАТЕРИАЛОВ НА ОСНОВЕ ДРЕВЕСИНЫ

The article presents the results of measuring the sorption humidity of three types of wood-based products: softwood plywood, hardwood plywood and oriented strand board. It has been established that oriented strand boards are the best option for wet operating conditions

Physics-based probabilistic capacity models and fragility estimates for light wood frame shear walls

Light wood frame buildings are common in the United States, and due to their prevalence, there has been significant damage to this type of building in previous earthquakes. For this building type, shear walls (typically sheathed with oriented strand board) are the main lateral force-resisting element. Probabilistic models and fragility estimates incorporating the prevailing uncertainties for shear walls are needed to make accurate predictions of the effects of future earthquakes on buildings of this type. This paper uses experimental data to develop probabilistic capacity models for the shear force and drift of light wood frame shear walls at the yield, peak, and ultimate performance levels. The proposed models are applicable to shear walls in low-rise buildings where the shear deformation is dominant. Moreover, the proposed models are applicable to walls that are similar to walls in the dataset. The probabilistic models are constructed starting from deterministic models. For the shear force, a new deterministic model is proposed. This model predicts the shear force capacity of the wall based on the capacity of individual nails. For drift, existing deterministic drift limits are used. The deterministic models are then improved by incorporating the effect of additional physical characteristics through explanatory basis functions that are shown to be significant in a probabilistic model selection procedure. Finally, fragility estimates are constructed for an example shear wall using the proposed capacity models and conditioning on the shear force and drift demands.

Numerical Analysis of the Racking Behaviour of Multi-Storey Timber-Framed Buildings Considering Load-Bearing Function of Double-Skin Façade Elements

The paper presents an innovative approach in the modelling of multi-storey timber-framed buildings, where double-skin façade elements (DSF) are additionally considered as load-bearing wall elements against a horizontal load impact. The mathematical model with a fictive diagonal element developed for timber-framed wall elements with classical oriented strand boards (OSB) or fibre–plaster sheathing boards (FPB) is upgraded for DSF elements. The diameter of the fictive diagonal is determined with either experimental results or numerically obtained results using the time-consuming FEM model with elastic spring elements, which simulates the bonding line between the timber frame and both glazing panes. In the second part of the study, the numerical analysis of a specially selected three-storey timber-framed building was performed using the developed mathematical model with fictive diagonal elements. Two alternative calculations were performed with the DSF elements as non-resisting and racking-resisting wall elements. It was demonstrated on the selected case that the racking resistance (R) of a building can essentially increase up to 35% if DSF elements are considered as resisting wall elements. As a secondary goal of the study, it is also important to point out that by using DSF elements as racking-resisting elements, the distortion in the first floor essentially decreased. It is demonstrated on the selected numerical example that this torsional influence decreased notably (by almost 18%) when the load-bearing DSF elements were used for seismic excitation in the X direction. Therefore, such an approach can open new perspectives in designing multi-storey timber-framed buildings with a more attractive and dynamic floor plan and structure.

Effect of wall sheathings on seismic behaviour of phosphogypsum-filled CFS shear walls

To improve the seismic behaviour of cold-formed steel (CFS) walls, a novel infilled CFS wall covered with different wall sheathings (gypsum wallboard, oriented strand board and fibre cement board) was assessed. Four full-scale specimens were tested under cyclic lateral loads to investigate the impacts of the wall sheathings on the seismic performance of the CFS wall. The failure process, failure mode, load–displacement curve, strength degradation, stiffness degradation, energy dissipation, deformation and strain variation of the walls were investigated. The failure modes of the walls were found to be failure of the connections between the CFS frame and the sheathing as well as crushing of the infill material. Compared with a specimen without sheathing, the peak load and lateral stiffness of the walls with sheathing were increased by 1.25–1.72 times, indicating that the sheathings played an important role in the lateral resistance of the wall. An analysis model and formulas for predicting wall lateral stiffness were developed. Comparisons between the calculations and experimental data showed that the proposed theoretical method was able to predict the lateral stiffness of the infilled CFS walls accurately.

Composite Beams Made of Waste Wood-Particle Boards, Fastened to Solid Timber Frame by Dowel-Type Fasteners

To increase the sustainability of prefabricated timber buildings and constructions, composite timber beams with "box" cross-sections were developed in collaboration with an industry partner. They were constructed from a solid timber frame and from webs made of residual waste wood-particle boards from prefabricated timber buildings production. The developed beams' design concepts presented in this paper were governed by architectural features of prefabricated timber buildings, geometrical limitations, available production technology, and structural demand related to various possible applications. The paper presents the results of experimental bending tests of six variations of the developed composite timber beams constructed by mechanical fasteners only. The developed design concept of composite timber beams without adhesives is beneficial compared to glued beams in terms of design for deconstruction and lower VOC emissions. The tests were conducted to study the influence of the following parameters on the beams' mechanical behavior: (i) web material (oriented strand boards (OSBs) vs. cement-particle boards); (ii) the influence of beam timber frame design (flanges and web stiffeners vs. flanges, web stiffeners, and compressive diagonals), and (iii) the influence of stiffener-flange joint design. Besides the beams' load-bearing capacities, their linear and non-linear stiffness characteristics were the main research interest. While adding compressive timber diagonals did not prove to significantly increase the stiffness of the beams in the case of cement-particle board webs, it increased their load-bearing capacity by enabling the failure of flanges instead of prior webs and stiffener-flange joints failure. For beams with OSB webs, failure of the bottom flange was achieved already with the "basic" timber frame design, but timber diagonals proved beneficial to increase the stiffness characteristics. Finally, mechanical characteristics of the developed beams needed in structural design for their application are provided together with further development guidelines.

Influence of Local Density on Concentrated Static Load Performance of Oriented Strandboard

Abstract Fourteen 1,220 by 2,440 by 11.1-mm commercial Oriented Strandboard (OSB) panels were X-ray scanned to obtain horizontal density matrices. Localized densities around the concentrated static load (CSL) testing points of the panels were calculated prior to the CSL test. A linear regression analysis was conducted to assess the impact of the localized density on CSL performance. The results indicated that both deflection and ultimate load were highly correlated with the local density. Deflection and ultimate load were somewhat correlated (R2 = 0.52). The CSL deflection decreased and ultimate load increased significantly with increasing local density. The impact of local density on ultimate load was greater than on deflection. Horizontal density variation is inherent in OSB manufacturing processes, especially in the mat forming process. A number of factors, including evenness of strands in the metering bin, condition of picker rolls and dissolving rolls, and strand and fines surging, can affect horizontal density distribution. OSB panels with a high degree of variation in horizontal panel density may cause low density spots that increase the chance of failure in CSL test. It is therefore crucial to minimize the occurrence of very low density areas in order to reduce the odds of ultimate load failure. Reducing density variability allows OSB companies to increase the CSL properties of their products, which would otherwise need to be done by making the panel denser. Improving horizontal density uniformity allows for lowering of the average panel density, which reduces the manufacturing cost and helps improve the company's bottom line.

Experimental investigation of the lumber-plybamboo-lumber screwed connections used in midply shear walls

Common midply shear walls constructed with wood-based mid-sheathing panels and nails usually exhibit substantial sheathing edge-tear and nail withdrawal failures, which will significantly limit the midply shear wall performance. This paper introduces an approach to prevent these connection failures, namely employing plybamboo panel and wood screw as middle sheathing and fastener, respectively. A preliminary experimental study on six groups of lumber-plybamboo-lumber screwed (LPLS) connections extracted from such improved midply shear walls were conducted, taking account of variables in terms of sheathing thickness and loading direction to the framing grain. Another three groups with Oriented strand board (OSB) mid-sheathings were tested for comparison. Test results show that the combined use of plybamboo panel and wood screw in the LPLS connections can effectively reduce the sheathing edge-tear and fastener withdrawal failures, and results in an over 70% increase in ultimate strength in comparison to the double-shear nailed connections with wood-based sheathing. However, the LPLS connections showed no advantage in elastic stiffness and ductility compared to the double-shear nailed connections with wood-based sheathing. The ultimate strength and ultimate displacement of the LPLS connections subjected to cyclic loading are 1.0–25.8% and 39.1–58.2% less than those of monotonically loaded connections, respectively, due to premature screw fatigue. The European Yield Model can reasonably predict the failure mode of the LPLS connections, but will underestimate the ultimate strength by 12–44%, probably due to underestimating the plybamboo embedment strength and ignoring the friction between plybamboo sheathing and SPF lumbers. The combined use of plybamboo panel and wood screw has great potential of being used in wood construction.