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Bamboo is a construction material that has great potential to be utilized as structural material on building construction. Bamboo available in variety length and high strength-weight ratio that make it ideal to be used as main structural component of buildings, such as column, beam, floor, partitions or trusses structural elements. High strength bamboo material can not be fully utilized due to the constraints in the connection system. The connection system adopted in joining bamboo elements on bamboo construction significantly influences the strength as well as behavior of the structure. The existence of nodes at the end of bamboo culms may improve the strength of connection. In practice, however, it is nearly impossible to have all bamboo element with nodes at the end of bamboo culms. Therefore in design of strength bamboo connection should be based on condition of end bamboo culms without nodes. In this research, analytical method considering two strength criterions is verified with result from experimental work. Results of research show that shear strength is the smallest strength among others. As bolt is used as connector in bamboo connections, shear strength commonly serves as critical criterion that determines the connection strength. This paper presents the result of study aiming at determination of minimum distance of bolt to the end of bamboo culms without node. Tests conducted by giving tensile force on the bolt with certain distance based on the analysis of shear strength and bearing strength of bamboo. The results showed that the critical distance of bolt to end of bamboo culms without node is 4-5 times the diameter of bamboo. Two main criterion of connection failure, namely shear and bearing failures are considered.

This paper focuses on the effect of polypropylene (PP) fibers on the mechanical properties and thermal conductivity of fly ash-based geopolymer foams. Class C Fly ash (FA) was used as a binder material. A mixture of sodium silicate (SS) and sodium hydroxide (SH) was used as an alkaline activator of the geopolymer binder. The foams were prepared mechanically by mixing the foaming agent with distilled water at high pressure. The foams were added to the geopolymer admixture with volumes of 40% and 60%. A small dosage of PP was varied from 0%, 0.25%, and 0.50% by weight of fly ash (FA). The result showed that the strength of foamed geopolymer rises as the PP fiber content increases. The PP fiber was proven to increase the tensile strength of foamed geopolymer due to the ability of PP fiber to connect the crack and improve the tensile strength. The PP fiber amount in this study significantly affects the thermal conductivity of foamed geopolymer. However, the thermal conductivity in this study has the same properties as lightweight concrete and a little higher than gypsum board.

High strength bamboo material cannot be fully utilized in construction projects due to the constraints of the connection system. The connection system element on the truss structure greatly affects the strength of the structure. Several studies have been completed to provide higher strength of the truss connections. However, the connection system is constrained by the costs of construction, availability of materials, equipment, skilled labored standardization. In this study, a connection system that possesses lightweight properties but with higher strength and lower cost while keeping the form of the bamboo being connected to remain natural has been developed. The proposed connection system consists of bolts, wooden gusset plates and special wooden clamps that have been adjusted with the shape and dimension of the bamboos being connected. A connection system without filler material on bamboo culms and wooden clamps used to increase the contribution to the shear at the connection has been proposed. The results showed an increase in the strength of the proposed connection of about 40% of the wood gusset plate system using wooden clamps than connection system without using wooden clamps, so it can be concluded that the proposed connection system possesses higher strength, yet much lower weight and has the potential for practical applications.

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