Abstract

Using by-products as alternatives to ordinary Portland cement (OPC) is attracting growing attention in the sustainable construction material sectors. Alkali-activated binders have been proposed and emerged as an alternative to OPC binders, which seem to have acceptable mechanical and durability performances in addition to positive environmental impacts. These alternative binders, also named “geopolymer,” use a wide range of aluminosilicate precursors, with differing availabilities, reactivates, costs, and CO₂ emissions. The usage of various materials results in obtaining the locally adaptable mix compositions, which establishes a broader toolkit. In this study, Petrit-T as a by-product from manufacturing sponge iron with fine particle-size distribution and rich in calcium was used to prepare the structural lightweight aggregates. Moreover, ground-granulated blast-furnace slag (GGBFS) as the binder was activated by a combination of sodium hydroxide and sodium silicate as the alkali activator. The effects of using different fiber types, including PVA, PP, and basalt, on mechanical properties were investigated. Mechanical properties were addressed in terms of the compressive and flexural strengths. The results showed that reinforcing the composition significantly affected the flexural performance. Moreover, it was revealed that using the granulated Petrit-T presented a lightweight concrete, with density ρ ≤ 1600 kg/m³.