Design and Characteristics of a Novel Casuarina Glauca Wooden K-Truss Formwork

Abstract

Beam-Truss wooden joists and stringers have been used extensively in the construction of reinforced-concrete floors in recent years due to their strength and ease of assembly and shuttering. However, the high price of such systems has always been a reason for why they are still not widely used in small-to-moderate-scale projects in developing nations. This high price is due to the high cost of the wood itself and the sophisticated know-how behind their manufacturing process. Hence, there is a need for reducing such costs through using cheaper woods that could be farmed on wastewater and using a simpler technique of manufacturing applicable on a wider scale without sophisticated know-how. This target has been achieved in this research through a truss designed and manufactured from Casuarina Glauca. Casuarina Glauca’s mechanical properties were found to be higher than most of the hardwoods but it was not tested in any structural applications before. In this paper, three trusses made of Casuarina Glauca wood were manufactured and tested until failure. The samples withstood loads higher than the design load and deflection and their failure pattern was not catastrophic. Furthermore, the cost of each truss was calculated. A case study was performed in which the developed system was used as joists and compared to two commercially available patented systems. This comparison covered the number of units, the total weight of the joists, and their total costs. The developed system was proven to provide significant cost-savings when compared to the other two.