文献类型：期刊文献

英文题名：Research on the Mechanical Properties and Microstructure of High Dosage β Hemihydrate Phosphogypsum-Based Composite Cementitious Materials

作者：Lu, Hongna Lian, Shuailong Du, Can Wang, Lei Liu, Qiumei Wu, Anjie

通信作者：Du, C[1]

机构：[1]Guizhou Inst Technol, Coll Civil Engn, Guiyang 550003, Peoples R China;[2]Hunan Univ Sci & Technol, Sch Resource Environm & Safety Engn, Xiangtan 411201, Hunan, Peoples R China

第一机构：贵州理工学院

通信机构：corresponding author), Guizhou Inst Technol, Coll Civil Engn, Guiyang 550003, Peoples R China.|贵州理工学院;

年份：2026

外文期刊名：JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE

收录：;EI(收录号：20260720092667);WOS:【SCI-EXPANDED(收录号:WOS:001690053800001)】；

基金：This research was supported by Guizhou Provincial Science and Technology Foundation (No. MS [2025]198), Natural Science Research Project of Colleges and Universities of Guizhou Provincial Department of Education (Youth Science and Technology Talent Development Project) (No. [2024]166), Guizhou Institute of Technology High-Level Talent Research Start-Up Funding Project (No. 2023GCC074, 2023GCC074), the Young Researcher Program of the Science and Technology Foundation of Guizhou Province (NO.QN[2025]218) , and National Natural Science Foundation of China (No. 52468019).

语种：英文

外文关键词：beta hemihydrate phosphogypsum; mechanical properties; microstructure; range analysis; water resistance

摘要：The co-preparation of phosphogypsum (PG) and silica fume (SF) to form PG-based composite cementitious material (PGCM) is an effective way to promote the resource utilization of PG, with enormous environmental benefits. This paper mainly focuses on high-dosage beta hemihydrate phosphogypsum (beta-HPG), formulates the L-9(3(4)) type orthogonal test scheme with SF, quicklime, polycarboxylate superplasticizer (PCS) and protein retarder (PR) as variables, and conducted physical and mechanical test on PGCM. The test results for PGCM cured for 14 days under natural, absolute drying, and saturated conditions showed that its flexural strength (FS) and unconfined compressive strength (UCS) fell within the ranges of 1.1-5.3 MPa and 3.3-22 MPa, respectively. The water absorption rate ranges from 16 similar to 26%, and the flexural and compressive softening coefficients are 0.38 similar to 0.64 and 0.27 similar to 0.59, respectively. Range analysis pointed out that the PR and SF have the greatest influence on the mechanical properties, and the water resistance performance is mainly affected by SF and PR, and the optimal ratios corresponding to different performance indicators were obtained by range analysis. Scanning electron microscope (SEM), x-ray diffractometer (XRD), Fourier-transform infrared (FTIR) and thermogravimetric (TG) test were also carried out on the specimen with the highest (PGCM1) and lowest (PGCM7) UCS under absolute dry state. The SEM analysis revealed the mechanism by which the 0.3% protein retarder weakens the strength: the dihydrate gypsum crystal structure of PGCM7 with 0.3% protein retarder is shorter, and has fewer connection points, a looser microstructure, more pores and a decrease in density, and leads to the poor mechanical performance. The hydration products of PGCM1 and PGCM7 were characterized by XRD and FTIR, and both samples contain the dihydrate gypsum (DG), quartz (SiO2), and calcium silicate hydrate (C-S-H) gel. The TG and DSC test showed the PGCMs have good thermal stability.