PSI - Issue 70

Maahira M. et al. / Procedia Structural Integrity 70 (2025) 642–649

643

1. Introduction Coarse aggregates used for the construction purpose was natural aggregates which was derived from natural resources by depleting the environment (Klima et.al., 2023). The depletion leads to imbalance topography, habitat destruction and increased green gas emission which was an unsustainable process (Alaa et.al., 2024). Hence artificial aggregates have been shown to exhibit comparable or even superior properties to natural aggregates, including improved durability, strength, and resistance to degradation (Xu et.al., 2021). The use of artificial aggregates can also reduce the carbon footprint of concrete production, as they require less energy to produce and can replace a significant portion of cement (Fan et.al., 2023). Hence we have developed a sustainable solution for the production of rock coarse aggregates using waste slag as a process of recycling. The wastes generated in the metal extractions were dumped into the land fill causing land pollution by depleting the soil fertility, reducing vegetation and causes ground water contamination (Huang et.al., 2024). Hence these waste left after metal extraction known as slag was used for the production of rock coarse aggregates in this study. GGBS was 18% cheaper than ordinary Portland cement and offers enhanced durability, improved workability, reduced thermal cracking and lower carbon footprint (Wei et.al., 2020). According to statistics in India, 15 million tonnes of GGBS was produced and only 55% was used in construction industry however the remaining GGBS was left unrecyclable (Bekkeri et.al., 2024). Those can be used for the production of artificial aggregates as GGBS is known as green building material as it emits less CO2. It also offers a promising solution to mitigate the environmental impacts associated with natural aggregate extraction and processing (Hamsashree et.al., 2024). In the literatures, artificial aggregates and lightweight aggregates were produced using pozzolanic material such as flyash and various sludge like sewage sludge, desulfurization sludge etc., and have proved to have its own pros and cons. In this study, GGBS and copper slag are taken at required ratio and mixed with geo polymer solution as binding material in the manufacturing process of aggregates. The aggregates properties were studied (viz., physical and mechanical properties) as per Indian code and compared with the properties of conventional aggregate. The aggregates were also oven cured and then tested for water absorption, specific gravity, impact test and crushing test. The optimum mix of artificial aggregate were used to cast M30 geopolymer based samples and tested for compression, split tensile test and water absorption. Nomenclature

GGBS

Ground Granulated Blast Furnace Slag

M

Molarity

SiO 2

Silicon dioxide or Silica

Fe

Iron

Al 2 O 3 Aluminum oxide MgO Magnesium oxide S Sulphur Cu Copper CO 2 Carbon dioxide NaOH Sodium hydroxide Na 2 SiO 3 Sodium silicate L/A Liquid Ash ratio CA

Conventional Aggregate

FA Fine Aggregate C-A-S-H Calcium alumino silicate hydrate M-Sand Manufactured Sand