Mechanical properties and mechanisms of alkali-activated slag paste reinforced by graphene oxide-SiO2 composite. (10th December 2022)

• Record Type: Journal Article
• Authors: Yang, Haibin; Hou, Dongshuai; Zheng, Dapeng; Tang, Luping; Tang, Waiching; Cui, Hongzhi
• Is Part Of: Journal of cleaner production. Volume 378(2022)
• Publication Date: 2022-12-10
• Subjects: Alkali-activated slag paste -- Graphene oxide-SiO2 -- Mechanical properties -- Strengthening mechanism -- Molecular dynamics; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2022.134502
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Alkali-activated slag (AAS) binders-based composites are considered potential alternatives to conventional cement-based composites. However, the quasi-brittle mechanical behavior of AAS binders-based composites limits their widespread application. In this study, a graphene oxide-SiO2 (GO-SiO2 ) composite was produced to address this issue. The experimental results showed that the flexural strength of an AAS paste increased by 133.2% with 1.5 wt% GO-SiO2 composite, and its corresponding flexural-to-compressive strength ratio increased 95% i.e. from 0.063 to 0.123. To explore the strengthening mechanism, the stability of the GO-SiO2 composite in alkaline solutions and the dispersion effect of GO-SiO2 composite on the mechanical properties of AAS paste were investigated. The experimental results showed that the prepared GO-SiO2 composite had stable C–O–Si chemical bonds connected GO with hydration products, thereby improving the strength of the AAS paste. The molecular dynamics study revealed the mechanism that the high-dispersed GO-SiO2 composite could improve the mechanical properties of the AAS paste dramatically. Highlights: The prepared GO-SiO2 composite exhibited excellent dispersibility in an alkaline solution. The stability of the C–O–Si chemical bond in the GO-SiO2 composite was investigated. Flexural strength of alkali-activated slag paste increased by 133.2% for the GO-SiO2 modification. Mechanisms of AAS paste reinforced by the GO-SiO2 composite were clarified.