Diverse effects of metal–organic frameworks on microstructure and compressive strength of cement-based composites. (March 2022)

• Record Type: Journal Article
• Authors: Yuan, Ning; Zhao, Aijing; Fang, Kuizhen; Wang, Dongmin; Zhang, Xinling
• Is Part Of: Cement & concrete composites. Volume 127(2022)
• Publication Date: 2022-03
• Subjects: Cement -- Metal–organic frameworks -- Compressive strength -- Microstructure; Composite-reinforced concrete -- Periodicals; Concrete -- Periodicals; Composite materials -- Periodicals; Composites de ciment -- Périodiques; Béton -- Périodiques; Composites -- Périodiques; Béton léger -- Périodiques; Cement composites; Composite materials; Composite-reinforced concrete; Concrete; Lightweight concrete; Periodicals; Electronic journals; 620.135
• DOI: 10.1016/j.cemconcomp.2022.104406
• Languages: English
• ISSNs: 0958-9465

Abstract

Abstract: The modern construction industry is continuously demanding the reinforcement of the mechanical properties of cement-based materials. To realize the targets, intensive investigations have been conducted through the fabrication of micro-/nano-particles–cement composites during the past decades. The present work aims to exploit the metal–organic frameworks (MOFs)-doped cement-based materials that have been rarely reported, including MOF-5, HKUST-1, ZIF-8, UiO-66, and MIL-68(Al). Their decomposition behaviors in the simulated cement pore solutions are observed, and results demonstrate that ZIF-8, UiO-66, and MIL-68(Al) maintain structural integrity, while MOF-5 and HUKST-1 are destroyed. With the doping concentration of 0.1 wt%, MOF-5 and ZIF-8 result in significant improvement in the compressive strength of hardened pastes. The 28-day compressive strength of hardened pastes C-MOF-5 increases by 28.75%, and C-ZIF-8 by 24.65%, which benefits from the promoting effect for cement hydration, the optimization for the product structures, and the filling effect. HKUST-1 and UiO-66 improve the 3-day and 7-day compressive strength of cement-based composites, but the enhancement of the 28-day strength is not dramatic. By contrast, the compressive strength of 28-day MIL-68(Al)-doped cement-based materials (C-MIL-68(Al)) decreases because of the augmented porosity, the excessive Ca(OH)2 crystals in the pores, and the generated calcium carbonate. These findings lay a foundation for the utilization of MOFs in cement-based composites. Graphical abstract: Image 1 Highlights: MOFs affected the compressive strength of cement-based materials variously. Distinct behaviors of MOFs in simulated cement pore solutions were disclosed. Compressive strength of the composites were elucidated in terms of microstructures.