Determination of the effect of waste foundry sand on the mechanical and radiation support properties of sifcon

This study aimed to experimentally investigate the effect of waste foundry sand (WFC), an industrial waste, on the mechanical properties of SIFCON (Slurry Infiltrated Fiber Concrete), a high performance concrete type, and to evaluate the usability of WFC as a sustainable and environmentally friendly construction material in this special type of concrete. ADC was substituted for stone dust at 0%, 20%, 40%, 60%, 60%, 80% and 100% of the aggregate components. Fresh concrete tests such as density, spread and flow time with V funnel were carried out. The results of these tests showed that there was a significant decrease in the workability of the mixtures with increasing ADC content. Following the fresh concrete tests, extensive analysis was carried out on the hardened concrete samples. SIFCON concretes were evaluated not only for their high mechanical strength but also for their physical, microstructural, economic and environmental aspects. Compressive strength and three-point bending tests were performed to determine the mechanical properties, while durability performance was evaluated by freeze-thaw cycles and sulfate impact tests with 5%-10% MgSO₄ solution. Within the scope of physical performance, radiation absorption capacity was also evaluated and analyzed depending on the ADC ratio. Scanning electron microscopy (SEM) was used to determine the phase distributions in the microstructure; the chemical composition was characterized by X-ray fluorescence (XRF) and the crystalline structure by X-ray diffraction (XRD). No significant decrease in mechanical strength was observed at ADK substitution rates up to 60%. However, the mechanical and physical properties of concrete deteriorated for admixtures above this level. In addition, the contribution of the use of ADK to production cost and environmental impacts was calculated; in particular, the reduction in carbon dioxide emissions was demonstrated. The compressive and flexural strength data obtained were statistically evaluated by reliability analysis.