INNOVATIVE SHEAR CONNECTION FOR THE COMBINATION OF BAMBOO-CONCRETE COMPOSITE BEAMS: EXPERIMENTAL STUDY

Abstract

Construction industry predominantly uses a reinforced concrete (RC), has a significant influence on global economic growth and environment. However, rising material cost, environmental degradation and sustainability issues are main concern with increasing demand for affordable housing now a days. Bamboo has become popular sustainable material because of its rapid growth and excellent tensile strength. But existing literature primarily focuses on engineered bamboo and knowledges on how to combine natural bamboo culm with other materials like concrete is still scarce and needs to be explored. This study developed and investigated the potential of different self-locking innovative shear connections through push-out and four-point bending experimental tests in collaboration with Hasselt University, Belgium. Dry natural High land bamboo culm (Oldeania Alpina) from Dawuro Zone, South-West Ethiopia and C25/30 concrete used with the bamboo undergoing traditional smoking treatment. A total of 12 beams, each with a 2.5-meter span, a width of 166 mm, and a depth of 160 mm, were tested along with their corresponding shear connections. The results indicated that self-locking innovative shear connections have significant potential to enhance mechanical properties of natural bamboo culm concrete composite beams (BCC). In particular, the experimental results revealed that BCC beams exhibited up to a 128% and 331% increase in both load carrying capacity and moment compared to control beams of only bamboo and plain concrete beam of the same cross section. Notably beams with Partially Split culm (PS) achieved a peak load of 29.66kN with a minimum deflection of 4.36 mm. The beam with another connection types showed improvement in load-bearing capacity from 169% to 290% and displayed gradual decline in capacity after peak load. The use of steel dowel bar highly improved slip behavior, deflection, and overall BCC beams mechanical properties. Future research on bamboo-concrete composites should examine durability under varied environmental conditions, address moisture content issues, conduct detailed flexural analyses, and expand sample sizes to improve understanding and applications in construction.