Investigation of mechanical properties of phosphorus building gypsum modified by multi-walled carbon nanotubes

Abstract

This study delves into the multifaceted effects of multi-walled carbon nanotubes (MWCNT) incorporation on phosphogypsum's properties. We investigated the phase composition and morphology of phosphogypsum and observed the influence of MWCNT on the setting time, flexural strength, compressive strength, water resistance, and hydration process. The results demonstrated that MWCNT significantly abbreviates the setting time of phosphogypsum, enhances its absolute dry flexural strength and compressive strength, and improves water resistance, with optimal effects occurring at a MWCNT content of around 1.00%. Nonetheless, these benefits diminish and can even be counterproductive if MWCNT content is excessively high. The enhanced properties of phosphogypsum upon MWCNT addition can be ascribed to the filling effect and mechanical interlocking facilitated by MWCNT. Additionally, MWCNT promoted the hydration of phosphogypsum, as evidenced by calorimetric measurements.

Keywords

• Phosphogypsum
• Multi-walled carbon nanotubes
• Flexural strength
• Compressive strength
• Hydration process