Treesearch

CORRIM, the Consortium for Research on Renewable Industrial Materials, has derived life cycle inventory (LCI) data for major wood products and wood production regions in the United States. The life cycle inventory data cover from forest regeneration through to final product at the mill gate. Research has covered nine major forest products including both structural and nonstructural uses and four major regions: in this report we focus on planed dry softwood lumber produced in the US Northeast-North central (NE-NC) region. The NE-NC regional data is a representative cross-section of forest...

Accounting for carbon sequestration in LCA illustrates the limitations of a single global warming characterization factor. Typical cradle-to-grave LCA models all emissions from end-of-life processes and then characterizes these flows by IPCC GWP (100-yr) factors. A novel method estimates climate change impact by characterizing annual emissions with the IPCC GHG forcing functions (w/m2/yr), integrated over the same 100-year time horizon, and then relating the warming to the equivalent time-zero equivalent (TIZE) CO2 emissions. Net life cycle carbon sequestration for lumber using TIZE and...

The effect of light stabilizer’s addition method into wood-plastic composites (WPCs), i.e., surface versus bulk, on their photostability was evaluated. Blends of ultraviolet absorbers (benzotriazole or hydroxyphenyltriazine) with a hindered amine light stabilizer were used as the stabilizing additives. Both unstabilized and photostabilized uncapped (control) samples, as well as coextruded WPCs counterparts, were exposed to up to 3000 h of accelerated artificial weathering. The light transmittance, surface morphology, and color of the samples before and after weathering were analyzed by...

Cross-laminated timber ( CLT) is defined as a prefabricated solid engineered wood product made of at least three orthogonally bonded layers of solid-sawn lumber or structural composite lumber (SCL) that are laminated by gluing oflongitudinal and transverse layers with structural adhesives to form a solid rectangular-shaped, straight, and plane timber intended for roof, floor, or wall applications (see Figure 1). While this engineered wood product has been used in Europe for over 15 years, the production of CLT and design of CLT structural systems have just begun in North America with some...

Cross-laminated timber ( CLT), a new generation of engineered wood product developed initially in Europe, has been gaining increased popularity in residential and non-residential applications in several countries. Many impressive low- and mid-rise buildings built around the world using CLT showcase the many advantages this product has to offer to the construction sector.

In early 2012, APA-The Engineered Wood Association conducted studies of three industries: institutional furniture, motor homes, and travel trailers and campers. The survey procedure was the same as that used by APA for many years. Lists of individual manufacturers were purchased, a telephone interviewing company was hired to administer a questionnaire, and APA processed the data to estimate total wood product volumes used by each industry and provide additional insights for each. A few problems were encountered with this research procedure including poor quality lists, difficulty in...

The extent of boron penetration in framing lumber treated by spray applications during construction is not well quantified. This study evaluated the effect of formulation and concentration on diffusion of boron in lumber specimens that were equilibrated in conditions that produced wood moisture contents of 18 to 21 percent. One set of specimens was pressure treated with water before equilibration. Borate solutions were prepared from powdered disodium octaborate tetrahydrate (DOT) or from two commercial glycol-borate formulations and applied with a garden-type sprayer. The DOT solution was...

The National Historic Covered Bridge Preservation Program (NHCBP), sponsored by the Federal Highway Administration (FHWA), is intended to preserve covered timber bridge structures nationwide. Today, less than 700 covered timber bridges still exist in the United States and of those many are closed to vehicular traffic. Furthermore, a large percentage of the remaining bridges open to traffic are restricted by load postings. Currently, no load rating standards exist for covered timber bridges which often results in overly conservative load ratings/postings. Rating engineers simply do not have...

Cross-laminated timber (CLT) is an innovative wood product that was developed approximately two decades ago in Europe and has since been gaining in popularity. Based on the experience of European researchers and designers, it is believed that CLT can provide the U.S. market the opportunity to build mid- and high-rise wood buildings. This Chapter presents a summary of past research and state-of-the-art understanding of the seismic behavior of CLT. As a new structural system to the United States, the design of CLT for seismic applications is expected to be made through alternative method...

The light weight of cross-laminated timber (CLT) products combined with the high level of prefabrication involved, in addition to the need to provide wood-based alternative products and systems to steel land concrete, have significantly contributed to the development of CLT products and systems, especially in mid-rise buildings (5 to 9 stories). While this product is well-established in Europe, work on the implementation of CLT products and systems has just begun in the United States and Canada. The structural efficiency of the floor system acting as a diaphragm and that of walls in...