Characterization of recycled aggregate by the combined method: Acid soaking and mechanical grinding technique

Every year, large quantities of construction and demolition waste are generated in India, which is a mixture of different grades of concrete. Such waste disposal required an immense amount of land and induced ecological pollution as well. Globally, researchers are trying to substitute coarse aggregate in concrete with recycled aggregate (RA). In the present paper, construction & demolition (C&D) waste was obtained from nearby the Jaypee University of Engineering and Technology, Guna. Where, due to the up-gradation of National Highway-3, a massive amount of building structures is demolished. In this work, a newly invented technique called pre-soaking in mild acetic acid (3%), followed by mechanical grinding using the Los Angeles abrasion machine for various durations was proposed for RA treatment. To assess the quality of RA, basic properties were studied, such as gradation, structure, abrasion value, crushing value, impact value, bulk density, and water absorption. Strength and durability properties of concrete made with RA were also studied. The improvement in RA’s quality after 72 h of pre-soaking in mild acetic acid (3%) followed by 7 min of mechanical grinding in a Los Angeles abrasion machine was observed optimum duration of treatment based on laboratory work. Strength and durability properties were also studied for concrete made with RA with different natural aggregate (NA) replacement levels (NA). The compressive and split tensile strength increased by 17.11% and 14.03%, respectively, in RAC compared to natural aggregate concrete (NAC) at the 100% replacement level. The innovative proposed technique is an effective one to implement in the field to produce RA to meet the construction industry’s demands.