Date of Publication

7-2025

Document Type

Master's Thesis

Degree Name

Bachelor of Science in Civil Engineering (Honors) - Ladderized

Subject Categories

Civil Engineering

College

Gokongwei College of Engineering

Department/Unit

Civil Engineering

Thesis Advisor

Dr. Bernardo Lejano

Defense Panel Member

Dr. Andres Oreta

Engr. Rainier Valdez

Abstract (English)

Bamboo is a renewable and sustainable material with mechanical properties that make it a promising alternative for use in structural applications within the construction industry. In the Philippines, where structures are frequently subjected to earthquakes and strong winds, ensuring structural reliability is essential. While researchers have extensively studied bamboo as a material, they have not sufficiently investigated the performance of its connections under shear forces. This lack of research presents a barrier to the broader adoption of bamboo in modern construction and underscores the importance of studying its connection behavior in greater detail.

This study examines the shear strength of a T-connection composed of a fish-mouthed bamboo secured with a steel J-bolt. The experimental program included three J bolt diameters and various combinations of mortar infill and clamping to examine their effects on joint performance. Statistical methods such as the t-test and multiple regression analysis were used to evaluate the significance of different material and geometric parameters. The results showed that increasing the J bolt diameter provided a slight improvement in shear capacity. However, the thickness and density of the bamboo had a more statistically significant effect on joint strength. Configurations that included both clamping and mortar infill consistently exhibited the highest

shear strength. The densest bamboo specimen with both reinforcement methods recorded the greatest strength among all tested configurations.

It was also observed that joints without mortar behaved like roller supports, allowing more displacement before failure, while joints with mortar acted like fixed supports, resisting movement more rigidly. This distinction provides structural designers with options depending on the intended support behavior in the structure.

Among the three prediction approaches analyzed in this study, which included the regression equation, the European Yield Model, and the proposed model equation, the proposed model equation proved to be the most accurate and consistent. It incorporates key parameters, such as the J-bolt diameter, the presence of mortar and clamps, and the geometry of the bamboo. The model separates the total shear capacity of the connection into two components: the shear strength of the bamboo and the shear strength of the bolt. The equation expresses Vt=Vb+ Vs kN the total shear capacity of the connection, where Vt is the total shear capacity, Vb is the shear capacity of the bamboo, Vs is the shear capacity of the bolt, and š¯›¼ is a coefficient that reflects how effectively the connection utilizes the boltā€™s shear strength under different conditions. The value of š¯›¼ varied depending on the presence of clamps and mortar, with 0.0432 for connections without clamps and mortar, 0.0849 for

those with clamps but no mortar, 0.1256 for those without clamps but with mortar, and 0.4051 for connections with both clamps and mortar.

Furthermore, a regression equation expresses the total shear capacity of the connection, showing greater variability and being best suited for simplified estimations when limited input data is available. On the other hand, the European Yield Model (EYM) is a design method used to predict the load-carrying capacity of dowel-type fastener connections in wood or bamboo by analyzing potential failure modes based on material strength and fastener deformation. The EYM produced accurate results only under specific conditions: the no-clamp, no-mortar setup and the with-clamp, with-mortar setup. The highest strength was observed in joints with 12 mm bolts, with mortar, and with clamps, highlighting the importance of combined reinforcement. Overall, the model equation serves as a conservative and practical design tool for evaluating the performance of bamboo connections in structural applications.

A case study evaluated the practical application of the proposed connection, using a 49-square-meter bamboo structure located near a fault line and considering both seismic and wind loading conditions. Using the developed modeling equation, the results demonstrated that the T connection can provide sufficient shear strength for use in low to mid-rise construction.

Specifically, the connection was found to be structurally feasible for one to three-story buildings, depending on the presence of clamps, mortar infill, and the bolt configuration applied. The result confirms the potential of the proposed connection for real-world use in disaster-resilient bamboo structures.

Abstract Format

html

Abstract (Filipino)

None

Abstract Format

html

Language

English

Format

Electronic

Keywords

Bamboo construction

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Embargo Period

2027

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Available for download on Friday, January 01, 2027

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