Strength development of fly ash concrete incorporating graphene nanoplatelets

Abstract

Concrete is the most popular building material in the world. As the requirement for development in infrastructure increases, the demand for the Ordinary Portland Cement concrete also increases. Furthermore, there are many demands on the innovative concrete, which is stronger, and cheaper than the conventional concrete. Thus, Graphene Nanoplatelets additive comes forward to overcome strength problems. As known, Graphene Nanoplatelets is sulphate material which has good electrical conductivity and ultrafiltration, strong, stiff, very light and more durable. It has been used as an alternative to improve the strength of fly ash concrete. In this study, the effects of graphene are evaluated for two different percentages which are 0.05% and 0.10%. Fly ash is waste material used as replacement to reduce the usage of cement and to predict positive strength of the concrete for it has pozzolan characteristics. Furthermore, it has been proven that concrete strength is increased when fly ash is used between 15-25%. Laboratory testing is the main method and is conducted to analyse the performance of graphene on fly ash concrete. It is based on BS 5328: Part 1:1991 and BS1881:1983. Grade 25N/mm2 is designed for concrete mixture 0.5 water to cement ratio. There are 60 samples tested, which are 36 cube and 24 prismatic samples with dimension of 100mmx100mmx100mm and 100mmx100mmx500mm respectively. Tests are performed on the 7th and 28th day of water curing. Results show that the workability of concrete is reduced with increased graphene but the mechanical characteristic of concrete is increased. From the result obtained, the optimum value occurs on day 28 with 0.05% of graphene. The optimum values of compressive and flexural strength are 25.031MPa and 4.72MPa respectively. In conclusion, as an additive, Graphene Nanoplatelets improves the strength development of fly ash concrete by increasing its strength and enhancing other characteristics.