Strength and Durability of Concrete Incorporating Blast Furnace Slag Aggregate as Replacement of Coarse Aggregates

Abstract

Lack of availability of land for waste disposal and high cost of construction material such as aggregates, we require in-expensive and low cost construction material that can be used in concrete industry. The report presents an investigation on strength and durability properties by replacing coarse aggregate with Blast Furnace Slag aggregates (BFS). Coarse aggregates were replaced with BFS aggregate in various proportions such as 0% (control mix), 20%, 40%, 60%, 80% and 100%. Various mechanical properties of concrete were evaluated for 7 and 28 days. In case of durability properties, sorptivity, rapid chloride permeability was evaluated at the age of 28 days. Additionally, microstructural investigation was carried out on samples using scanning electron microscope to get a deeper insight in the mineralogical constitution and behavior of such mixes when used for construction purposes. Mechanical and the durability properties of concrete get enhanced when 60 percent of coarse aggregates were replaced by BFS aggregates. Due to increased C-S-H gel a compact structure was noticed and the same was verified by SEM technique also. Thus, it leads to a growing interest in the development of new concrete type, due to its high performance, durability, better serviceability and overall economy in the long run.