Compression Behavior of Cross-Laminated Timber Wall Panels with Different Reinforcement Mechanisms

Abstract

The main objective of this work is to characterize the stress–strain relationship of cross-laminated timber (CLT) wall panels when loaded in compression and how different confinement mechanisms provide compression reinforcement for the CLT panels. CLT crushing tests were performed to define the behavior of CLT under compression up to the failure point, defined here as the strain at which the gross stress falls by 20% from the peak value. Testing included monotonic uniform compression experiments of five-ply CLT with specimens that were 0.457 m wide by 1.52 m long. The motion of the specimens perpendicular to loading direction was restrained at midlength to prevent buckling. Twelve specimens were tested, including six bare CLT specimens and six reinforced specimens of CLT—three with self-tapping screws while the other three with self-tapping screws and an additional U-shape steel plate at the bottom of the specimens. Various damage points were observed during the tests, including (1) point at the onset of damage (through visual observation and instrumental observation) (2) point of initiation of strength degradation, (3) point at which buckling occurs, (4) point at which 25.4 mm delamination was observed, and (5) failure point. Three axial compression stress–strain models were adopted, calibrated, and compared. Results indicate that a stress–strain model combining linear and cubic functions for the elastic and softening responses, respectively, captures well the CLT inelastic behavior under compression.