The increasing scarcity of sand for construction is driving up the cost of sand, which in turn is affecting overall construction works in Asian countries. Therefore, it is essential to go for an alternative material to reduce the load on the traditional sand in underdeveloped nations. The purpose of this paper is to examine the influence of e-waste (0–25%) as an alternate for fine aggregate on the thermal and residual mechanical performance of cement concrete (CC) and geopolymer concrete (GC) mixes exposed to elevated temperatures following the International Organization for Standardization 834 fire curve.
Concrete specimens with varying proportions of e-waste were incorporated for both CC and GC mixes. These specimens were subjected to elevated temperatures (30–120 min) to simulate real fire conditions. The properties of the concrete were evaluated (density, porosity, crack width and residual compressive strength). The comparative performance of CC and GC was analyzed using experimental results.
Results showed that a decline in density and compressive strength, alongside an increase in porosity and crack width with an increase in exposure duration. Moreover, GC outperforms CC mixes in the case of thermal resistance. GC mixes exhibited higher residual strength (up to 17.2 MPa after 30 min and 4.5 MPa after 120 min), lower porosity (0.03%) and reduced crack width (0.02 mm), demonstrating improved fire resistance. The addition of e-waste (EW) had a marginal effect on mechanical strength at room temperature but contributed to enhanced thermal performance. GC showed 20–30% higher residual strength than CC after exposure to 1,029 °C.
This study introduces a sustainable approach to concrete production by utilizing e-waste as an alternative to fine aggregate and evaluating thermal resilience in both CC and GC. The results show that the incorporation of e-waste is a positive alternative to conventional sand, thereby reducing the need and demand for it (especially in the case of GC), which paves the way for sustainable construction practices.
