Joints with bamboo slats for shear wall frames

Abstract

Bamboo is a rapid-growing plant that is a sustainable candidate to replace highly contaminating materials in housing projects. Bamboo slats are a promising alternative to using bamboo culms, as they have a higher bulk density, can be easily extracted from defective culms, and have a geometry that can be more easily controlled to standard dimensions. This study proposes joints for bamboo slats to be used in the frameworks of shear walls. To this end, three connections for Guadua bamboo slats were proposed and tested under monotonic loading to determine their moment-rotation behavior. A first joint to connect two slats was composed of two platens that compressed the slats along their wall thickness by tightening bolts. Monotonic tests of this joint showed its high ductility (range 9.5 – 38.8) and results dependent on bolt grade since the rotational stiffness and the ductility for grade-2 bolts were about 1.3 and 2.0 times significantly different than those for the specimens with grade-5. Two other proposed joints for multiple-slat members were composed of bamboo pins, platens, bolts, wood wedges, stainless steel sheets, and self-tapping screws. Significant differences were not found in the ductility and rotational stiffness of these two joints, which were in the range of 1.7–4.2, and 4954–8984 N-m/rad, respectively. However, the maximum moment (range 1172–1362 N-m) for the joint with a cedar wedge was around 1.5 times significantly higher than that (range 782–942 N-m) with a steel clamp. The multiple-slat joints displayed a relatively high ductility, while other mechanical parameters were similar to those reported in the literature for joints connecting members of substantially higher cross sections. The use of moment-resistant joints may improve the mechanical performance of shear-wall frameworks under seismic loading, enhancing the versatility of the system and providing alternatives to extend the application of bamboo for housing.