Characterization and use of biomass power plant ash in sulfoaluminate cementitious materials

• Published in: Construction & building materials 2022-03, Vol.325, p.126667, Article 126667
• Main Authors: Xie, Hongzhang, Ren, Changzai, Zhao, Baofeng, Liu, Suxiang, Zhu, Di, Guan, Haibin, Xu, Dan, Wang, Jingwei, Yang, Huajian
• Format: Article
• Language: English
• Subjects: Biomass power plant ash (BPPA); Compressive strength; Construction materials; Sulfoaluminate blended cement (SAC); Washed BPPA
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2022.126667

[Display omitted] •Proposed to use industrial solid waste instead of part of SAC clinker to synthesize SAC blended cement.•The effects of biomass power plants ashes on the performance of SAC blended cement were analyzed.•The effect of biomass power plant ashes on SAC blended cement hydration was analyzed. Using biomass power plant ash (BPPA) as an alternative to cement-based materials is an effective way to achieve high value utilization of industrial solid waste. In this study, BPPA was used to replace part of sulfoaluminate cement (SAC) clinker to produce SAC blended cement, and the influence of different BPPA contents on the mechanical strength, rheological properties, and microstructure of the SAC blended cement mixture was explored. The hydration mechanism of the SAC blended cement and the impact of washed and unwashed BPPA on SAC blended cement were analyzed by XRD, XRF, SEM, FTIR, TG, and DTG. The results showed that although replacing SAC clinker with 20%–30% BPPA decreased cement strength, an appropriate amount of BPPA (10%–15%) could significantly improve the mechanical strength of SAC blended cement. Meanwhile, the fluidity of cement pastes increased, and the setting time was prolonged with increasing BPPA replacement rate. In addition, SAC blended cement prepared with untreated BPPA had better mechanical properties than composite cementitious material prepared with washed BPPA. The compressive strength of unwashed BPPA composite cementitious material in 28 days could reach 80 MPa, whereas SAC blended cement prepared with washed BPPA only reached 50 MPa. Therefore, it was feasible to produce SAC blended cement by replacing SAC clinker with 10%–15% BPPA. This study provided solutions to the BPPA waste management problem and helped to minimize the consumption of energy-intensive cement to provide SAC blended cement and to meet the growing needs of the construction industry.