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...
To evaluate the mechanical performance of the cross laminated timber (CLT) as the structural board materials using domestic species, the delamination test and the transverse bending test were conducted. The CLT used in the tests consisted of 3 layers of laminated timber made of Japanese larch and Korean red pine. The combinations for...
The glulam is determined by, and therefore a representation of, a new kind of ecological structural materials. The aim of this study was to summarize the mechanical performance especially the flexural behavior of various kinds of glulam and the physical...
Structures built with cross laminated timber (CLT) are an attractive alternative to traditional construction materials in terms of environmental performance and habitability, but its structural behavior is not well understood for each timber specie. This work provides a comprehensive study of the structural behavior of radiata pine...
International Conference on Innovative Materials, Structures and Technologies
September 30-October 2 2015, Riga, Latvia
Cross-laminated timber is an environmentally friendly material, which possesses a decreased level of anisotropy in comparison with the solid and glued timber. Cross-laminated timber could be used for load-bearing walls and slabs of multi-storey timber buildings as well as decking structures of pedestrian and road bridges. Design methods of cross-laminated timber elements subjected to bending and compression with bending were considered. The presented methods were experimentally validated and verified by FEM. Two cross-laminated timber slabs were tested at the action of static load. Pine wood was chosen as a board's material. Freely supported beam with the span equal to 1.9 m, which was loaded by the uniformly distributed load, was a design scheme of the considered plates. The width of the plates was equal to 1 m. The considered cross-laminated timber plates were analysed by FEM method. The comparison of stresses acting in the edge fibres of the plate and the maximum vertical displacements shows that both considered methods can be used for engineering calculations. The difference between the results obtained experimentally and analytically is within the limits from 2 to 31%. The difference in results obtained by effective strength and stiffness and transformed sections methods was not significant.
This project studied the effect of openings on the lateral performance of CLT shear walls
and the system behavior of the walls in a module. Three-layer Cross Laminated Timber
(CLT) was used for manufacturing the wall and module specimens. The laminar was
Spruce-Pine-Fir (SPF) #2&Better for both the major and minor layers. Each layer was 35
mm thick. The panel size was 2.44 m × 2.44 m.
Four configurations of walls were investigated: no opening, 25% opening, 37.5% opening,
and 50% opening. The opening was at the center of the wall and in the shape of a square.
A CLT module was made from two walls with 50% openings, with an overall thickness of
660 mm. The specimens were tested under monotonic loading and reverse-cyclic loading,
in accordance with ASTM E564-06 (2018) and ASTM E2126-19.
The wall without opening had an average peak load of 111.8 kN. It had little internal
deformation and the failure occurred at the connections. With a 25% opening, deformation
within the wall was observed but the failure remained at the connections. It had the same
peak load as the full wall. When the opening was increased to 37.5%, the peak load
decreased by 6% to 104.9 kN and the specimens failed in wood at the corners of the
opening. Further increasing the opening to 50%, the peak load dropped drastically to 63.4
kN, only 57% of the full wall.
The load-displacement relationship was approximately linear until the load reached 60%
of the peak or more. Compared to the full wall, the wall with 25% opening had 65% of the
stiffness. When the opening increased to 37.5% and 50%, the stiffness reduced to 50% and
24% of the full wall, respectively. The relationship between stiffness and opening ratio was
approximately linear. The loading protocol had effect on the peak load but not on the
stiffness. There was more degradation for larger openings under reverse-cyclic loading.
The performance of the module indicated the presence of system effect that improves the
ductility of the wall, which is important for the seismic performance of the proposed
midrise to tall wood buildings. The test data was compared to previous models found in
literature. Simplified analytical models were also developed to estimate the lateral stiffness
and strength of CLT wall with openings.
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.