Multimetallic MOF-74-M reinforced lightweight concrete: Enhanced impact resistance and environmental durability

The advancement of high-performance, durable lightweight construction materials is crucial in modern civil engineering, particularly for applications exposed to impact and harsh environments. In this study, a multimetallic MOF-74-M nanostructure incorporating Zn, Ni, and Pd was synthesized via hydrothermal methods and employed as a nano-reinforcing additive in lightweight foamed concrete (LFC). The objective was to enhance both impact resistance and long-term environmental durability of the cementitious matrix. The fabricated composites were subjected to comprehensive testing including impact energy absorption, compressive and flexural strength, drying shrinkage, sulfate and acid resistance, chloride ion penetration, water absorption, ultrasonic pulse velocity, and porosity analysis. Experimental results showed that incorporating 4 wt.% MOF-74-Ni increased the maximum impact energy absorption by 1197 J, improved crack resistance by 697 J, and reduced porosity by up to 23% compared to control specimens. Additionally, water absorption was reduced by 25%, and drying shrinkage decreased significantly, enhancing durability. Chloride penetration and sulfate resistance also improved, with compressive strength retention after 25 weeks of acid exposure exceeding 80%. SEM, XRD, FTIR, and XPS analyses confirmed strong interfacial bonding and structural stability of MOF-74-M within the matrix. These enhancements are attributed to the uniform dispersion, high specific surface area, and multifunctional properties of the MOF particles. The results indicate that multimetallic MOF-74-M is a promising candidate for multifunctional nanocomposite systems in sustainable construction, offering both mechanical resilience and superior durability against aggressive environmental conditions.