Insights into the mechanical and environmental behaviors of artificially phosphogypsum-based lightweight aggregate and its sustainable application

This study proposed a new phosphogypsum-based lightweight aggregate (PGLA) in an attempt to replace traditional gravel aggregate for embankment filling purposes. Self-developed stabilizer (namely CTGU-NL stabilizer, including phosphogypsum, ground granulated blast-furnace slag, and lime) was applied on these two aggregates to compare their mechanical and environmental behaviors. Sensors were buried in two different fields to track the time-dependent variation of nitrogen, phosphorus, potassium concentration, electrical conductivity, temperature, and humidity. Core samples were collected at predesigned curing periods to obtain the unconfined compressive strength (UCS). Thereafter, scanning electron microscopy (SEM) and back scattered electron (BSE) tests were combined to investigate the microscopic property changes of samples particularly in the interfacial transition zone (ITZ).