1effect of Graphene Oxide on the Hydration and Performance of Phosphogypsum-Based Self-Leveling Materials Used for Floor Heating Backfill

Abstract

Gypsum-based self-leveling materials (GSLMs) are extensively utilized in floor heating backfill systems due to their rapid setting and hardening, non-shrinkage, non-cracking, low carbon footprint, environmental friendliness, and excellent biocompatibility. A key technical challenge is enhancing the thermal conductivity of GSLMs to improve the energy efficiency of floor heating systems. This study explores the incorporation of graphene oxide (GO) into phosphogypsum-based self-leveling materials (PGSLMs) to enhance their thermal conductivity. It also examines the effects of GO on workability, mechanical properties, hydration processes, and microstructure of PGSLMs. Results indicate that GO promotes the dissolution of hemihydrate gypsum and cement particles, crystallization of dihydrate gypsum, and formation of a crystal network structure. As GO dosage increases, thermal conductivity linearly rises, fluidity decreases, setting time shortens, and mechanical properties initially improve before diminishing. Optimal mechanical properties are achieved at a GO dosage of 1.00%, with increases of 22.07% in compressive strength and 12.90% in thermal conductivity.

Keywords: Self-leveling materials, Phosphogypsum, graphene oxide, Thermal conductivity, hydration