Structural performance of rubber-padded fabricated galvanized iron (GI) clamp as connectiors between full culm bamboo rafters and wall top plates/
Hannah Lyn Y. Basa, Reina Mae A. Bautista, Ranred Tom D. Cuello, Josephine T. Padaboc, Monarose A. Roca, and James Edrian A. Rubio .--
- Manila: Technological University of the Philippines, 2024.
- xxii, 219pages: 29cm. +1 CD-ROM (4 3/4in.)
Thesis (undergraduate)
College of Engineering .--
Includes bibliography:
Bamboo construction has yet to reach its full potential as difficulties with its joints and connection arise due to bamboo’s hollow round shape and varying diameters. In line with this, this study proposes a new connection with galvanized iron clamps padded with nitrile butadiene rubber, as clamps can effectively distribute the load throughout the connected bamboo, and nitrile butadiene rubber can prevent slippage. Utilizing a full culm Bambusa blumeana treated with borax and boric acid, a rafter-to-wall top plate connection was made using the fabricated clamp. To determine the suitability of the bamboo for construction, ASTM D2395-17, ASTM D1037-12, and PNS ISO 22157:2020 were followed for physical and mechanical property tests. The tensile, shear, and grip tests were also conducted in three trials each to determine the structural performance of the clamps with varying widths (1 in, 1.5 in, and 2 in). Furthermore, the clamps’ performance was compared to the designated design loads and the conventional bolted connection. The obtained results demonstrated the proposed connection's successful performance in both the tensile and shear tests with strengths 6.257 kN and 2.083 kN, respectively. When compared to the designated design loads of 3.389 kN and 0.492 kN in tension and shear respectively, the clamps’ performance exceeds by: Clamp A - 53.97%, Clamp B - 84.63%, and Clamp C - 69.53% for tension; Clamp A - 446.68%, Clamp B - 323.41%, and Clamp C - 214.34% for shear. Additionally, there is no significant difference in terms of stiffness between the clamp and the bolted connections’ performance in resisting tensile forces. However, talking about their modes of failure is another thing. The clamp underwent various stages - elongation of the clamp, deformation of its pocket, then detachment from its joint—all these happened while protecting the bamboo. On the contrary, for the bolted
vi connection, the bamboo split first before the connector itself which makes it less efficient as a bamboo connector. The findings of this study reveal that among the three samples of the proposed connection (1 in, 1.5 in, and 2.5 in clamp), the 1.5-inch clamp proved robust in withstanding tensile, shear, and sliding forces, making it a suitable full-culm bamboo rafter-to-wall top plate connector. Still, this can only be justified with a good workmanship of the fabrication of the clamp and its assembly especially the tightening of the nuts. Lastly, thisstudy can be continued by utilizing other materialssuch asstainlesssteel or by applying the connection to other structural members.