Assessment on structural and mechanical properties of reinforcement concrete beams prepared with luffa cylindrical fibre

So much study has been done and is currently being done on the possibilities of using natural fibres to increase the concrete strength, to lower the cost of production and to reduce the negative effects of concrete production on our environment. The structural behaviour of flexural-loaded reinforced concrete beams incorporated with different grades of concrete (normal, high, and ultra-high strength) and a constant percentage of luffa cylindrical fibre (0.75% of the volume) was studied. The experimental programme comprised two phases; phase one was the design of mixtures, and phase two was concrete beams, for the three types of concrete grades. Six beams were tested under one point load as part of the experimental programme. Three beams served as control specimens, whereas the other three beams were cast with constant percentages of fibre having various types of concrete. One type of luffa cylindrical fibre was used with a fixed size and a constant percentage added to all mixtures. The effects of two major variables were considered and empirically investigated. These variables were the influence of the concrete grade and fibre addition, which were reflected in the six tested beams. Each beam was loaded to failure, and the test data were analysed to examine the mode of failure, ultimate load, load–deflection relationship, stiffness, ductility factor, and toughness. Compared with the control beams (without fibre), all beams with fibre for three types of concrete showed an increase in ultimate load, stiffness, and toughness; otherwise, a decrement in ductility factor was reported. In addition to a better structural behaviour as shown by microstructure analysis.