BOND STRENGTH OF BANANA STEM FIBER REINFORCED CONCRETE UNDER NON-STANDARD CURING

Abstract

Today, worries about the problems and impacts of environmental damage have become a reality, so the use and development of novel, environmentally friendly materials is a challenge. The presence of natural fibers in concrete materials, among others, functioned to improve the mechanical characteristics of concrete materials, retarded cracks in structural components up to certain loading levels, and reduce structural failure due to corrosion of reinforcing steel. The influences of the percentage of banana stem fiber and variation in bar diameters on the bond strength and other mechanical properties in non-standard curing conditions need to be investigated. This research presented a study of the use of banana stem fiber obtained from the waste of the banana pseudo stem, which is available in large quantities in Indonesia. This experiment method uses a push-off test on the cylindrical specimen. Results show that the larger the plain reinforcement diameter, the smaller the development of bond strength, so the bond strength of banana stem fiber reinforced concrete, called NBSFRC, is inversely proportional to the diameter of the plain reinforcement. The development of bond strength increased significantly at the early ages of the specimen for plain reinforcing bar diameters of 10 mm and 12 mm. Another aspect that may strongly affect the bond strength is the curing process that is not maximal, because after casting, the specimen cannot be immersed in the tub as other test specimens for curing to avoid fast corrosion, but only be wrapped in gunny sacks and watered daily.