Performance Study and Multi-Index Synergistic Effect Analysis of Phosphogypsum-Based Composite Cementitious Material

The application of phosphogypsum in building materials can consume waste phosphogypsum and reduce ecological pressure. In this study, building phosphogypsum was used as the base material, and fly ash, lime, cement, and other materials were added to explore the performance of phosphogypsum-based cementitious composite building materials via orthogonal experimental method. Variance analysis and multiple regression analysis were used to summarize the performance variation of these phosphogypsum-based composite cementitious materials. This work demonstrates that the building phosphogypsum content and the water-cement mass ratio are significant factors affecting the thermal conductivity and mechanical properties of these materials scanning electron microscopy (SEM) analysis showed that the mechanical properties and thermal insulation properties of the prepared phosphogypsum-based composite cementitious materials were good in the C-S-H gel system and ettringite formation uniform specimens. Regression analysis showed a significant relationship between the building phosphogypsum content, fly ash content in the supplementary cementitious material, lime content, water-cement mass ratio, compressive strength, and thermal conductivity. The compressive strength and the thermal conductivity were analyzed by the index membership degree. The comprehensive performance of the phosphogypsum-based composite cementitious materials was evaluated, and basic theoretical research into the use of the phosphogypsum-based composite cementitious materials in a building non-load-bearing wall was carried out.