Study on Cl- solidification characteristics and enhancement principle of alkali excited materials modified with high-performance strong base anion exchange resin

• Published in: Construction & building materials 2024-09, Vol.442, p.137314, Article 137314
• Main Authors: Yang, Zheming, Li, Faping, Lu, Yiyan, Ning, Anran, Li, Shan
• Format: Article
• Language: English
• Subjects: Alkali-excited materials; Cl- solidification; High-performance strong base anion exchange resin; Response surface methodology
• ISSN: 0950-0618
• DOI: 10.1016/j.conbuildmat.2024.137314

In this paper, a high-performance strong base anion exchange resin (HP-SBAER) suitable as a modifying additive for alkali excited materials (AEM) was prepared. The interaction between the independent variables (cross-linking degree, porosity and dispersibility) was explored by means of Box-Behnken Design (BBD) in Response Surface Methodology (RSM). HP-SBAER demonstrated a significant improvement of 8.01 % in mechanical properties and 41.57 % in Cl- solidification ability compared to SBAER. In addition, HP-SBAER had strong resistance to failure and stable Cl- solidification ability. HP-SBAER doping into AEM released OH-, which ensured the alkaline environment of AEM and promoted the condensation of AEM. The intergranular spacing of the crystal molecules decreased and the crystallinity improved. In addition, the newly generated C(N)-A-S-H gel filled the pores, and the pore size distribution developed toward harmless pores. The incorporation of HP-SBAER into M-AEM mortar modulated its fluidity and initial setting time, while having minimal impact on the final setting time. The optimal doping of HP-SBAER was determined to be 3 wt%. At this doping amount, the fluidity of the M-AEM mortar was 245 mm, and the initial and final setting times were 51 min and 80 min, respectively. Under a Cl-environment, the mechanical properties of the M-AEM improved by 25.66 %, and the Cl- solidification ratio increased by 115.38 % in the Cl- environment. The performance advantage of the M-AEM was more obvious in a high Cl- environment. •A high-performance resin modifier (HP-SBAER) was prepared to improve the durability of AEM in Cl- environments.•HP-SBAER enhanced alkaline environment and improved AEM microstructure and crystal structure.•HP-SBAER significantly improved the Cl- solidification properties of AEM and reduced the rate of strength loss in Cl- environments.