Southern Pine (SP) is one of the fastest growing softwood species in the Southern Forest of United States. With its high strength to weight ratio, SP becomes an ideal candidate for manufacturing engineered wood products such as cross laminated timber (CLT). Two batches of CLT panels were manufactured using visually graded SP lumbers in this study: pilot-scale panels in a laboratory setting and full-size panels in a manufacturing plant environment. The first batch of pilot-scale CLT panels was manufactured at Clemson University. The second batch of full-scale CLT panels (3m x 12.2m) was produced and CNC-sized by Structurlam in Penticton, Canada and shipped to Clemson University for testing. Four types of structural wood adhesives were selected in the panel production, namely Melamine Formaldehyde (MF), Phenol Resorcinol Formaldehyde (PRF), Polyurethane (PUR) and Emulsion Polymer Isocyanate (EPI). This paper presents the manufacturing process of SP CLT in a laboratory setting as well as structural performance verification of 3- ply SP CLT in terms of rolling shear and bending properties. The obtained performance data of 3-ply CLT in both major and minor strength directions is verified against PRG-320 Standard for Performance Rated Cross Laminated Timber. Tested results are presented and discussed.
This paper presents the preliminary design of a rocking Cross-laminated Timber (CLT) wall using a displacement-based design procedure. The CLT wall was designed to meet three performance expectations: immediate occupancy (IO), life safety (LS), and collapse prevention (CP). Each performance expectation is defined in terms of an inter-story drift limit with a predefined non-exceedance probability at a given hazard level. U-shape flexural plates were used to connect the vertical joint between the CLT panels to obtain a ductile behavior and adequate energy dissipation during seismic motion. A design method for ensuring self-centering mechanism is also presented.