Mechanical properties, radiation mitigation and fire resistance of OPC-recycled glass powder composites containing nanoparticles

Abstract

The main target of this research is the utilization of low- cost nanoparticles as substantive additions for bolstering the physicomechanical, mitigation of gamma radiation, thermal stability and morphological characteristics of OPC-recycled glass powder hardened composites. Nano MgO and MgFe2O4 spinel NPs were synthesized via the sol–gel route. Characterization of MgO (NM) and MgFe2O4 (NMF) spinel NPs was done using XRD, SEM, TEM, and EDX techniques. Compressive strength, water absorption, bulk density, and total porosity results revealed that partial replacement of OPC by different ratios of waste glass powder waste (WGP) affect negatively on the physicomechanical properties of hardened composites. Inclusion of NPs (NM or NMF) 0.5 and 1 mass % boosts the physicomechanical features of different OPC-WGP hardened composites at most curing ages. The activity of synthesized MgO and MgFe2O4 NPs was affirmed via TGA/DTG and XRD techniques which indicated the formation of diverse hydration yields like CSHs, AFt, AFm, CASHs, MH, CAHs, MSH, CFSH, and CFH that enhances the physicomechanical characteristics as well as the γ- rays shielding % of different OPC-WGP hardened nanocomposites. The thermal stability test was performed at elevated temperatures (300, 500 and 700 °C) for 180 min for all hardened prepared composites after curing for 28 days under normal conditions. The results indicated that the composite containing OPC-10WGP-0.5NMF showed the highest thermal stability. These results were confirmed via SEM/EDX images which displayed a compact and closely packed microstructure of rods-like crystals of CSHs, stacked plates of CASHs, ettringite fibers and symmetrical hexagonal sheets of CH.