Treesearch

Rosewood and palisander belonging to Dalbergia (Fabaceae) are some of the most studied tree species in Madagascar. Dalbergia species can be identified based on morphological differences, mainly of flower and fruit, but are practically impossible to tell apart when these structures are missing. To support their sustainable management reliable identification of living Dalbergia is necessary prior to any exploitation. Studies of the vegetative anatomy of Dalbergia are lacking. This is the first report on young stems and leaves in endemic Dalbergia species. We studied 16 Dalbergia species from...

Significant research has been conducted on the development and use of hardwood resources in engineered wood materials and products. This research focused on utilizing undervalued hardwoods for applications that take advantage of their excellent strength properties. Some of the results from this research have been implemented by industry, and additional research has been initiated and is on-going. To bring together industry leaders and scientists, Mississippi State University and the USDA Forest Service, Forest Products Laboratory, led a workshop on this topic in 2023. The objectives of the...

The current study assessed the efficacy of heartwood extracts from Tectona grandis, Dalbergia sissoo, Cedrus deodara, and Pinus roxburghii, combined with linseed oil, as protectants for two non-durable wood species against termites and decay fungi. Stakes measuring 45.7 × 1.9 × 1.9 cm and blocks measuring 12.5 × 3.75 × 2.5 cm of the sapwood of southern pine (Pinus sp.) and cottonwood (Populus sp.) were impregnated via vacuum pressure with individual heartwood species extract, linseed oil, or a combination of both. For comparison, solid heartwood stakes and blocks of the wood species used...

Cross laminated timber (CLT) has become a popular wood composite in large building applications that were previously limited to concrete and steel. To extend service and prevent biological attack, chemical protectants are often applied to wood. Cross laminated timber panels are not typically treated, in part due to a lack of data on efficient and effective methods for treating large panels. There are also limited long term field data regarding the exposure of CLT to biological attack. In this study, commercially prepared CLT panels consisting of either 5-ply Norway spruce or 3-ply southern...

The ability of insecticidal soil drenches or spray-on insecticide/fungicide treatments to protect mass timber elements exposed in a high moisture environment but out of direct soil contact was assessed using a modified AWPA ground proximity test established in 2017. Three-ply Douglas-fir CLT pieces measuring 305 x 355 x 105 mm (L x H x W) were installed at the Harrison Experimental Forest (HEF) (Saucier, Mississippi) in 2017. Test samples were placed in sets of two on bricks approximately 150 mm apart, 75 mm above the soil and covered with ventilated waterproof covers. A total of 20 test...

In this study, CLT trailer decking was manufactured to current military trailer decking specifications, verified using PRG320 performance criteria, and treated with either waterborne or oil borne wood preservatives. Preliminary results show adequate uptake of preservative solution and subsequent testing shows minimal effect due to treatment. Field durability tests are also being conducted of treated and untreated materials in tropical sites in Suriname and 8-month data is presented herein. Presence of gaps in the CLT layup have proven problematic as it presents a pocket for collection of...

The main purpose of this study is to quantify and compare the embodied carbon (EC) from the materials used or designed to build the Adohi Hall, a residence building located on the University of Arkansas campus in Fayetteville, AR. It has been constructed as a mass timber structure. It is compared to the same building design with a steel frame for this study. Based on the defined goal and scope of the project, all materials used in the building structure are compared for their global warming potential (GWP) impact by applying a life cycle assessment (LCA) using a cradle-to-construction site...

Evaluation of physical and mechanical heterogeneity in commercial paperboards is needed to promote their use in structural applications, especially within the field of packaging. Understanding the range of their behaviors is needed to compete with other materials in the current marketplace and expand in others. This work describes the physical and stiffness heterogeneities of twelve commercial materials using tensile tests in the cross-machine direction and several inverse analyses. The effects of grammage, thickness, and apparent density on tensile stiffness were evaluated in both the...

Wood (or timber) mats are portable and temporary modular platform assemblies that spread short duration heavy loads from construction equipment out across large areas, protecting the environment from rutting and erosion. They are used throughout the United States and around the world. These assemblies facilitate access to construction sites and provide stable working surfaces during infrastructure and construction projects. Some examples of these types of projects include dragline operations, pipe- and transmission-line building and rebuilding, wind and cellular tower construction, crane...

Structural insulated panels (SIPs) are an important construction material that has been developed through many years of research at the USDA Forest Service, Forest Products Laboratory. There are concerns, however, related to the in-service performance of this important construction material. More data are needed to determine creep performance of these panels to help the industry address these concerns. This report describes a test method that was developed to measure the creep performance of SIPs. Topics covered in this report include a summary of the development of sandwich-type structural...