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 .--

Thesis (undergraduate)

College of Engineering .-- Bachelor of Science in Civil Engineering: Technological University of the Philippines, 2024.

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

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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.