Comparative analysis of shear strength parallel to grain of different local bamboo species

There are limited published studies related to the mechanical properties of bamboo species in the Philippines. In this study, the shear strength properties of some economically viable bamboo species in the Philippines, e.g. Gigantochloa apus, Bambusa philippinensis, Bambusa vulgaris, Dendrocalamus asper, and Bambusa blumeana were properly characterized based on 232 shear test results. The rationales of selecting this important mechanical property are the following: (1) Shear strength parallel to the grain has the highest variability among the mechanical properties; and (2) Shear is the governing force on joint connections and such connections are the points of failure on bamboo structures when subjected to extreme loading conditions. ISO 22157-1 test protocol for shear was used for all tests. The results showed that Bambusa blumeana has the highest average shear strength (f = 11.44 MPa) followed by Gigantochloa apus (f = 10.77 MPa), Dendrocalamus asper ( f = 10.31 MPa), Bambusa philippinensis ( f = 9.68 MPa ), and Bambusa vulgaris ( f = 9.26 MPa ). However, comparative analysis using One-way ANOVA showed that shear strength values among these bamboo species have significant difference statistically. ) and basic density (ρ) equal to 0.0158 is suggested. The model f = 0.0128ρ + 2.1786 is likewise suggested. These models yielded the lowest percent error when comparing the results generated by these models versus the actual values obtained from the test. Characteristic shear strength is also determined using (ISO 12122-1) as a future design reference. The characteristic shear strength obtained for each bamboo species are as follows: Gigantochloa apus (f ,4 = 5.11 MPa); Bambusa philippinensis (f ,4 = 7.26 MPa); Bambusa vulgaris (f ,4 = 6.46 MPa); Dendrocalamus asper (f ,4 = 6.98 MPa); and Bambusa blumeana from Tarlac, Philippines (f ,4 = 5.15 MPa); Results similarly showed that shear strength of bamboo is comparable to some Philippine timber species thereby strengthening bamboo’s position as a sustainable alternative construction material