PSI - Issue 70

Ravi Malik et al. / Procedia Structural Integrity 70 (2025) 682–689

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3. Optimization and Future Directions Using an 800- sample dataset, Ahmed et al. (2021) evaluate the σc of FA-BGPC and identify the curing temperature (50 – 80°C for 24 hours), sodium silicate-to-hydroxide ratio (SS/SH: 1.5 – 2.5), and molarity (10 – 16 M) as the main influencing factors. Although the alkaline solution-to-binder ratio (l/b) has varying effects, heat curing increases early strength. The study highlights the feasibility of FA-BGPC as an environmentally benign material made from fly ash and other industrial waste, and it recommends more durability studies (such as fatigue and chloride resistance) to increase construction use. The scope is expanded by Castillo et al. (2021), who specify the activator type (sodium hydroxide and silicate mix), curing conditions (80 – 90°C for early strength, longer periods for total σc), and Si/Al ratio (ideal at 1.5 – 2.0) as crucial to geopolymer σc. Higher water content increases porosity, which lowers σc, but excess Si/Al weakens the material because of unreacted particles. In contrast to harmful heavy metal impurities, controlled calcium increases strength. The study urges investigation of various aluminosilicate sources by positioning geopolymers as mechanically competitive with PCC and having fewer emissions. Geopolymer concrete (GPC) is reviewed by Parcesepe et al. (2022), who highlight its early strength and lower resource requirements through the use of recyclable resources like fly ash and cementless binders. Although conservative design projections continu e, mechanical parameters (σc, tensile strength, and elastic modulus) change with mix design and curing, indicating structural potential in beams and columns similar to OPC. Widespread use is hampered by high costs, uneven characteristics, and a lack of design codes, despite the environmental advantages. In order to improve design standards, research on ambient curing and long-term durability is called for, along with applications in prefabrication and transportation (such as in the USA and Australia). Zhang et al. (2023) concentrate on geopolymer recycled aggregate concrete (GPRAC), which incorporates fly ash, slag, and metakaolin binders with recycled aggregates (RA). With the addition of fibers and nanoparticles, as well as optimum curing, GPRAC shows enhanced mechanical qualities (tensile, flexural, and σc strength) and durability (freeze-thaw, sulfate, and chloride resistance). By lowering porosity and water absorption (by 18.97% and 25.33%), modified RA helps achieve green goals by reducing emissions. However, there are issues with RA variability and interfacial zone porosity, which call for studies on RA therapies and quality requirements. All of these investigations support the mechanical potential and sustainability of geopolymer concrete, which is fueled by the use of fly ash and ideal curing conditions (50 – 90°C). However, practical obstacles (cost, norms), durability gaps (e.g., chloride resistance), and mix design variability continue to exist. To fully realize its promise in environmentally aware building, further studies should focus on ambient curing, long-term performance, and consistent formulations. 5. Conclusion A revolutionary development in environmentally friendly building, geopolymer concrete (GPC) provides a workable answer to the problems with standard Portland cement's effects on the environment. The remarkable mechanical qualities of GPC are highlighted in this paper, including its high compressive strength (up to 108 MPa), increased tensile strength, and improved resistance to chemical attacks such sulfuric acid and chloride penetration. These qualities result from its special geopolymerization method, which drastically lowers CO2 emissions by using industrial wastes like fly ash and slag. The study reveals important variables that affect GPC performance, including additive integration, curing techniques, activator concentration, and precursor selection. Strength development is accelerated by heat curing (50 – 100°C), whereas ambient curing techniques — although slower — are essential for realistic cast-in-situ applications. GPC is appropriate for sewage and marine infrastructure due to its exceptional resistance to harsh environments, as demonstrated by durability testing. However, obstacles to broad adoption still exist, such as mix design unpredictability, expensive costs, and the lack of defined codes. The creation of performance-based standards, long-term durability evaluations, and ambient curing procedure optimization should be the main areas of future research. Sustainability could be further improved by investigating the utilization of industrial byproducts and unusual waste materials. By tackling these issues, GPC has the potential to transform the building sector and provide a long-lasting, environmentally responsible substitute that supports international sustainability objectives. The review's conclusions highlight GPC's capacity to reduce environmental effects without sacrificing structural soundness, opening the door for its wider adoption in building methods.