Due to the high volume of timber required for manufacturing, the production of cross-laminated timber (CLT) panels could be an appropriate destiny for the existing surplus of pinewood presently available in Uruguay. Although wood construction is uncommon in this country, there are some companies with the capacity to adapt their production to new products such as CLT. This work evaluates the properties of CLT panels manufactured in Uruguay with local pine (Pinus taeda and Pinus elliiottii) from forest plantation thinning, which typically present low mechanical properties. Boards and panels were mechanically tested and the mechanical properties were determined, showing a strength class lower than C14. A numerical model, using the finite element method, was developed and the numerical results were compared with the experimental values. The results provided a first approach to the conditions and limitations of the use of CLT panels for building floors, produced under the current manufacturing conditions in Uruguay.
This thesis is part of a larger project where lumber from small logs harvested in restoration programs was examined for use in CLT; panels were manufactured utilizing lumber from small logs and the mechanical properties were assessed. While another team focused on mechanical testing to examine the technical viability of this concept according to current manufacturing standards, the objective of this thesis was to assess the practical feasibility of this conception within the supply chain (C. Lawrence, 2017). This research focuses on the Blue Mountains–a region in eastern Oregon.
The approach was based on analysis of previous literature, Forest Service Cut & Sold reports, and semi-structured in-person and telephone interviews of federal timberland foresters, sawmill personnel, and management of current and potential cross-laminated timber manufacturers.
This research suggests that if the regional supply chain in the Blue Mountains were to process more small diameter logs into lumber, this will increase the available supply of 2x4 and 2x6 dimensions of lumber for use in a variety of different markets rather than for exclusive use in the center layers of cross-laminated timber panels.
Project contact is Henry Quesada at Virginia Polytechnic Institute and State University
The goal of this project is to create a new market for hardwood use in the manufacturing of cross-laminated timber (CLT) panels. Currently, the CLT code PRG-320, only accepts selected softwood species for the manufacturing of CLT panels and all work conducted on increasing hardwood use in CLT’s has focused on producing and using them as structural components. In this project, we will focus on creating an opportunity to increase hardwood use in CLT by adding hardwood to the outer layers of CLT’s, primarily for its visual appearance. Many CLT panels are used as wall and flooring components and other materials are added for decorative walls and flooring. By using hardwood on the outer layers of softwood CLT’s, we can increase hardwood use. Hardwood veneer and lumber will be added to the outer layers of CLT panel cores made from southern yellow pine in compliance with PRG-320. This project will partner with Danzer Veneer America, Allegheny Wood Products (AWP), and Texas CLT to manufacture and evaluate the performance and potential market acceptance of CLT panels made with hardwood veneer and lumber on the outer layers. We will evaluate for delamination of the hardwood veneer and lumber from the softwood core and determine what influence the hardwood layers have on the strength properties of CLT. We will conduct a market perception test of the hardwood veneer laminated CLT panels among architects and structural designers in the U.S. We believe that the results of this work could increase the market for hardwood veneers and lumber by 10% of the current consumption.
The current interest and growth of cross laminated timber (CLT) products has spurred interest in the manufacture of CLTs in the United States. The purpose of this paper is to explore the development of CLT materials from southern pine lumber commonly available in Virginia. A 5-layer CLT panel has been constructed using No. 2 southern pine lumber. Evaluation of mechanical properties, fire performance and acoustical performance were conducted. Results of these evaluations can guide the development and acceptance of CLT products in the International Building Code.
Project contacts are Linda Zimmer and Cory Olsen at the University of Oregon
During the testing and fabrication of mass timber projects a natural byproduct inevitably occurs in the form of offcuts and cutouts. In the case of new mass timber structures, the engineered wood materials are typically fabricated and prepared off site, allowing for the majority of the leftover materials to be made into useful products at the same facility already ideally set up for further digital fabrication. While the thickness of many of the spare panelized elements under investigation/production at TDI might seem excessive for smaller scale elements, the digital design and production techniques already being used allow for a fine degree of precision commensurate with furniture joinery. We propose to experiment with designing and fabricating furniture scale components and furniture prototypes as a way to reclaim these otherwise unused timber products. This project captures off cuts and remaindered materials from structural testing at TDI in both CLT and MPP panels.
Our focus is the design and fabrication of freestanding furnishings (ex: stools, benches, tables, chairs) that will exploit the technologies available at the Emmerson Lab. We come at this with two perspectives: in the first, products could be made directly from the materials available; in the second, the output will act as a formwork or “jig” to facilitate construction of an entirely new prototype that could expand into additional material languages. In either case it is important to us to share digital files of prototypes as “open source” designs so that production facilities and design professionals can work together to reduce waste and/or use our designs as a springboard to customize their own pieces. In this way we address the stated program goals to expand and develop new products and building components and to foster markets for these. Our iterative approach to digital design and digital hybrids utilizes CNC/robotic fabrication and assembly and we will be testing our ideas in a design-build format.
Cross-laminated timber (CLT), a new generation of engineered wood product developed initially in Europe, has been gaining popularity in residential and non-residential applications in several countries. Numerous impressive low- and mid-rise buildings built around the world using CLT showcase the many advantages that this product can offer to the construction sector. This article provides basic information on the various attributes of CLT as a product and as structural system in general, and examples of buildings made of CLT panels. A road map for codes and standards implementation of CLT in North America is included, along with an indication of some of the obstacles that can be expected.
This study surveyed experts on Cross-Laminated Timber (CLT) on their perspectives about research with the most positive impact on the advancement of CLT as building material in North America. Results from this study show that CLT experts in North America believe that architects are relatively well informed about CLT compared with...
Cross-laminated timber (CLT) is a building system based on the use of massive, multi-layered solid wood panels. Although CLT as a construction system has been successful in Europe, only a handful of CLT projects have been built in the U.S. This manuscript presents the results from qualitative research, carried out with the objective of assessing the market potential and barriers to the adoption of CLT in the U.S. Insights from national and international experts were collected using semi-structured interviews. Topics included perceived benefits and disadvantages of CLT as a construction system, major barriers to its adoption in the U.S., and level of awareness about CLT among the architecture community.