Suitability Study on Strength Properties of Crumb Rubber in Geopolymer Concrete

Abstract

Due to an incessant upsurge in the construction industry and the steep increase in the cost of raw materials, researchers are focusing on various resources that can be replaced with cement as a construction material. One such material that is rich in Silicon and Aluminium is Flyash. Flyash as an additive to concrete made a way for a contemporary material that was coined as Geopolymer Concrete (GPC). In Geopolymer, alkaline activators such as sodium hydroxide or potassium hydroxide are mixed with sodium silicate so as to form geo-polymerization with products like GGBS, flyash etc. and which as a result binds the aggregate. This paper mainly emphasizes on role of Crumb Rubber (CR) in the formation of GPC replacing the fine aggregates by various percentages (5% - 15%) of CR. The Geopolymer mix design is proposed for M40 grade. Compressive and tensile strength tests were carried out on concrete modified with Flyash and GGBS (Ground Granulated Blast Furnace Slag) in 60:40 ratios. At a molarity of 14M, ratio of sodium silicate to sodium hydroxide is maintained as 2.5. The samples were placed in an ambient condition and were tested for strength on 7, 14 and 28 days. Based on the experimental results, it was observed that use of CR in GPC does not enhance the strength properties and cannot be used in high-end structural applications only.