Preparation of high flexural strength rankinite cement benefiting from formation of aragonite whisker during carbonation curing

Abstract

This study centers on a novel approach of high flexural strength rankinite (3CaO·2SiO₂, abbreviated as C₃S₂) cement benefiting from in-situ formation of aragonite whisker (AW) during carbonation curing. The manufacturing parameters including MgCl₂ concentration and reaction temperature play key influence on formation of AW. The results showed that high temperature favored AW formation and AW with length-diameter ratio of 15 ∼ 30 could be generated with concentration of Mg²⁺/Ca²⁺ molar ratio of 0.1 at 70 °C. Under this condition, the flexural strength of the C₃S₂ cement reached 7.5, and 15.6 MPa after 3d and 28d and the corresponding compressive strengths were 30.2 and 71.1 MPa, respectively. The results also showed that 40.9% of CO₂ by mass was consolidated in rankinite paste after 48 h, suggesting a promising prospect for calcium silicate-containing waste residue and cement to capture CO₂ and simultaneously manufacturing high-performance materia.

Keywords:

• flexural strength
• low-carbon cement
• CO2 utilization
• carbonation curing
• magnesium chloride

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors are grateful to the financial support by the Science and Technology program of Jiangsu province (BZ2020012), the National Natural Science Foundation of China (52108250, U2001225), the Opening Project of State Key Laboratory of Green Building Materials (2022GBM01), The natural science foundation of Jiangsu higher education institutions of China (22KJB560030), China’s building materials industry ‘to select the best candidates for key research’ project and Joint project of CNBM Innovation Technology Academy Co., ltd.