Work

Effects of Mg-based admixtures on chloride diffusion in alkali-activated fly ash-slag mortars

Year: 2024

Type: article

Abstract: This study evaluated the effects of various Mg-based admixtures, including magnesium oxide (MgO), layered double hydroxides (LDH), and calcined layered double hydroxides (CLDH), on the chloride resistance of alkali-activated fly ash-slag (AAFS) mortars. To this end, chloride diffusion tests were conducted on AAFS mortars containing 5 wt.% MgO, Mg-Al-CO3 LDH, and CLDH. The results revealed that all Mg-based admixtures investigated in this study enhanced the chloride resistance of AAFS mortars. The inclusion of MgO led to a finer pore structure and promoted the formation of more Friedel's salt, thereby enhancing the chloride resistance performance. Although the inclusion of Mg-Al-CO3 LDH and CLDH resulted in more lager pores in the matrix, leading to slightly lower compressive strength, the overall content of Mg-Al LDH and Friedel's salt formed in the system increased, which led to an improved chloride binding capacity and enhanced chloride resistance.

Source: Case Studies in Construction Materials

DOI: 10.1016/j.cscm.2024.e03659

Authors: Jingxiao Zhang, Yuwei Ma, Zuhua Zhang, Xiaocong Yang, Xingzhong Nong, Hao Wang

Institutions: Tongji University, Guangzhou University, Guangzhou Metro Group (China), University of Southern Queensland

Language: English

Topic: Concrete and Cement Materials Research

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,110

Funder: National Natural Science Foundation of China