Strength, microstructural, and leaching characteristics of phosphogypsum-fly ash mixtures
Strength, microstructural, and leaching characteristics of phosphogypsum-fly ash mixtures
Phosphogypsum (PG) is a waste product from the fertilizer industries producing phosphoric acid and phosphate fertilizers. On the other hand, fly ash (FA) is the by-product of thermal power plants. This paper presents a comprehensive study of the application of PG in combination with FA in road construction. The PG-FA mixtures are prepared in 70:30, 60:40, 50:50, and 40:60 ratios at 97% of maximum dry density (MDD) and corresponding water content. The California bearing ratio (CBR) of mixes is then evaluated after 4 days of soaking. The risk of contamination is also determined by performing Toxicity Characteristic Leaching Procedure (TCLP). In addition, Field Emission-Scanning Electron Microscopy (FE-SEM) is conducted to identify the microstructural changes and interaction of PG-FA mixtures. Results indicate that all the mix proportions have CBR values greater than 10%, while the PG:FA proportion of 50:50 was optimal. The TCLP test results suggest that the concentrations of various trace metals are within the threshold limits specified by USEPA (1992).
Y. Thakur; Akanksha Tyagi; S. Sarkar
18th European Conference on Soil Mechanics and Geotechnical Engineering (ECSMGE2024)
E - Environment, water and energy
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