Cross laminated timber (CLT) is a new engineered wood product that has experienced rapid growth and market acceptance for residential and non-residential construction in western and central Europe. Potential exists for rapid market adoption in North America if manufacturing capacities are developed. Dissemination of information on CLT North America markets, manufacturing capabilities, and product standards are the next key steps for facilitating investment in CLT manufacturing capacities in North America. This paper compares standards for CLT between Europe and North America.
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.
Cross laminated timber (CLT) connections in shearwalls require an understanding of the shear strength and stiffness of panel-to-panel connections within the wall. This research measures the strength and stiffness of three different panel-to-panel CLT connections considering both monotonic and cyclic loading. Connections included a laminated veneer lumber (LVL) spline, a half-lap connection and a butt joint with overlapping steel plate. All connections were ductile in nature. The butt joint with steel plate demonstrated the highest connection strength of the connections tested. The cyclic stiffness of the laminated veneer lumber spline was less than the monotonic stiffness, while the halflap joint experienced a sharp drop in load after ultimate load was achieved. Full details of the monotonic and cyclic behaviour will be discussed, including load, stiffness and ductility terms.
The purpose of this paper was to examine whether CLT made from fast growing hardwood species can provide sufficient mechanical performance need to be used in structural engineering applications. Yellow-poplar CLT was tested experimentally for stiffness and strength in five-point bending and four-point bending tests, respectively as well as resistance to shear by compression lading and resistance to delamination and the results were compared with American National Standard Institute/APA-The Engineered Wood Association (ANSI/APA) PRG 320-Standard for Performance Rated Cross-Laminated Timber and previous research. Bending stiffness, bending strength and resistance to delamination exceeded the required value in the standard, while wood failure in resistance to shear by compression loading was less than the required value. Shear strength of the yellow-poplar CLT was also greater than CLT produced from softwood species tested in previous research. Acceptable mechanical performance of yellow-poplar CLT confirmed in this research, could be a start point of using hardwood species in CLT structural design.