Experimental study on the mechanical properties of modified phosphogypsum at different loading rates

Area of Science:

• Materials Science
• Geotechnical Engineering
• Environmental Engineering

Background:

• Phosphogypsum (PG) is a major industrial solid waste from phosphoric acid production.
• Modified phosphogypsum (MG) shows potential for environmental sustainability and engineering applications.
• Understanding MG's mechanical properties under different loading conditions is crucial for its utilization.

Purpose of the Study:

• To investigate the mechanical properties of modified phosphogypsum (MG) under various uniaxial compression loading rates.
• To analyze the influence of loading rates on stress, strain, and energy characteristics of MG.
• To provide a theoretical basis for the engineering application of MG as a building material.

Main Methods:

• Uniaxial compression tests were performed on modified phosphogypsum (MG).
• Four distinct loading rates were applied: 0.03, 0.06, 0.12, and 0.6 mm/min.
• Mechanical responses, including stress-strain behavior and energy evolution, were analyzed.

Main Results:

• MG exhibited creep at 0.03 mm/min, quasi-static loading at 0.12-0.6 mm/min, and transitional behavior at 0.06 mm/min.
• Crack initiation stress, damage stress, and peak strength increased with loading rate, with diminishing amplitude.
• Elastic strain energy increased steadily, while total and dissipative strain energies showed a decrease followed by a slow increase with rising loading rates.

Conclusions:

• MG's mechanical properties are significantly influenced by loading rates, dictating its deformation behavior.
• The study provides critical data on the strength and energy characteristics of MG under different loading scenarios.
• These findings support the viable engineering application of modified phosphogypsum as a sustainable building material.