利用原状磷石膏制备石膏基复合胶凝材料的力学性能

Mechanical property of phosphogypsum based composite cementing material prepared with original phosphogypsum

以未经处理的原状磷石膏制备磷石膏基复合胶凝材料,测试磷石膏基复合胶凝材料的力学性能,考察生石灰的掺量、水灰比以及成型压力对磷石膏基复合胶凝材料力学性能的影响。结果表明:当生石灰掺量为4%时,磷石膏-矿渣复合胶凝材料具有较好的力学性能,矿渣微粉对磷石膏-粉煤灰复合胶凝材料的力学性能有增强作用。对于磷石膏-矿渣-炉渣复合胶凝材料,当成型压力超过3 MPa时,制备的材料力学性能明显下降。同浇注成型试样相比较,在5 MPa成型压力下的压实成型试样,材料孔隙率提高,特别对于200 nm以上孔所占体积分数来说,其所占体积分数要远远高于浇注成型试样,导致了材料微观结构劣化,力学性能变差。

Original untreated phosphogypsum was used to prepare a kind of phosphogypsum based cementing material,the mechanical property of the prepared material was tested and effects of quicklime content,water/cement ratio and molding pressure on the mechanical property were investigated.The results showed that with the quicklime content of 4%,the phosphogypsum slag composite cementing material had a good mechanical property,slag power had a positive correlation with the mechanical property of the phosphogypsum fly ash composite cementing material,and the mechanical property of the phosphogypsum slag boiler slag composite cementing material decreased as the molding pressure was greater than 3 MPa.Compared with the specimens prepared by casting molding method,the total porosity value of the specimens prepared under 5 MPa molding pressure was larger,especially for the volume fraction of more than 200 nm pore.Its microstructure would be destroyed,thus its mechanical property was decreased.