Durability performance of concrete incorporated with alkali-activated artificial aggregates
Gopal Bharamappa Bekkeri, Kiran Kumar Shetty, Gopinatha Nayak, Abhilash Kumar K A
Abstract
Abstract The surge in infrastructure projects has spurred a surge in demand for concrete, putting pressure on the supply of key raw materials, notably aggregates. Innovative approaches have been devised to address this challenge, including developing alkali-activated artificial aggregates (AAAs). These aggregates were crafted from a blend of seashell powder, fly ash, and slag through an alkali-activation cold-bonding technique. The concrete containing up to 50% replacement of natural coarse aggregates with AAAs depicted optimum mechanical properties. As the studies on the durability perspective of concrete with artificial aggregates were limited, extensive studies on durability characteristics, such as resistance to elevated temperature, acid, sulfate, chloride, seawater intrusion, reinforcement corrosion, and others, were determined. Some prime results of alkali-activated artificial aggregate concrete (AAAC) mix after 90 days of curing depicted a water absorption of range 0.16–0.2% and sorptivity of 1.86–7.43 × 10 − 5 mm/Sect. 0.5 .When exposed to the sulphuric acid solution, the strength loss ranges between 41.66 and 43.89%, and the thermal conductivity was 1.08–1.98 W/m⁰C. Mass loss of steel bars embedded in concrete mixes exposed to accelerated corrosion test varied between 24.5 and 33.5 g for a cover of 40 mm. In addition, at an elevated temperature of 800⁰C, the concrete mixes presented a strength loss range of 15.38–20.4%. Overall, the comprehensive findings of this study underscore the viability of artificial aggregate-based concrete in meeting stringent durability standards. Moreover, by repurposing waste materials, this research significantly contributes to sustainable construction practices, curbing the environmental footprint of concrete production while enhancing its performance and longevity.