Fracture Toughness and Resistance-Curve Behaviour of Laminated Bamboo

Abstract

In this study, the fracture toughness and resistance curve behaviour of laminated panels, produced from the tropical Nigerian bamboo species Bambusa vulgaris, were investigated to assess its potential for use as an alternative construction material. Round bambooculms were processed into laminated panels. The Mode I fracture toughness K IC , and the resistance-curve (R-curve) behaviour of the laminates in the crack arrester and divider orientations were investigated using ASTM E399 single-end notch bend (SENB) specimens. Results showed that the bamboo laminate had a higher resistance to crack propagation in the arrester orientation than in the divider orientation, with average fracture toughness of 11.24 MPa √m and 8.51 Mpa √m respectively. Modest rising R-curve behaviour was observed in both orientations and the predicted estimates of the toughening levels using the small-scale bridging (SSB) and large-scale bridging (LSB) models showed trends that were consistent with the tests observed in the experimental resistance curves. The implications of these results are discussed, as it affects the use of bamboo laminate as an alternative construction material.