Insights on the performance of sintered silt ash-blended cement: experiments and thermodynamic simulation

Frontiers in Materials

Materials

Wu-Jian Long¹  Qiling Luo¹  Zhipeng Li²  Zhengxiang Liu³  Hongguang Zhang⁴ 

[1] Guangdong Province Key Laboratory of Durability for Marine Civil Engineering, Shenzhen University, Shenzhen, China;Key Laboratory of Earthquake Engineering Simulation and Seismic Resilience of China Earthquake, Tianjin University, Tianjin, China;Poly Changda Engineering Co., Ltd., Guangzhou, China;State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, China;

关键词: microstructure;    sintered silt ash;    hydration;    thermodynamic modeling;    portland cement;   

DOI  :  10.3389/fmats.2023.1264307

 received in 2023-07-20, accepted in 2023-08-14,  发布年份 2023

来源: Frontiers

【 摘 要 】

The dredged silt exposed to the air is highly expected to be used to replace cement in large quantities due to its richness in aluminosilicates, which is in line with the dual-carbon background. Herein, a systematic exploration on the basic properties and hydration products of sintered silt ash-blended (SSA-blended) cement is conducted, using experiments and thermodynamic simulations. The results show that in the process of adding SSA to 50%, the compressive property and chloride ion permeation resistance are enhanced first and then weakened, whereas the flexural property is weakened gradually. Among them, with the addition of 10% SSA, the compressive strength can reach 65.2 MPa and the electric flux is 37.3% lower than that of Portland cement (PC), and the chloride ion permeability is rated as the lowest. As SSA increases, the FTIR spectra show that the reduction rates of bound water, ettringite and Ca(OH)2 are accelerated gradually; SEM observation shows that the cement-based gelling skeleton has undergone a transition from dense to loose; the thermodynamic simulation results show that C-S-H increases first and then decreases, implying that SSA has a certain pozzolanic activity. In addition, the evolution laws of other hydration products are highly consistent with the analysis results of FTIR and SEM.

【 授权许可】

Unknown   
Copyright © 2023 Li, Liu, Zhang, Luo and Long.