Doped multi-walled carbon nanotubes and nanoclay based-geopolymer concrete: An overview of current knowledge and future research challenges

This in-depth review aims to shed light on the application of nanoclay and multi-walled carbon nanotubes in geopolymer concrete. It comprehensively examines the profound impact of these nanomaterials on the physical, chemical, and mechanical properties of geopolymer concrete. The review delves into the intricate details of the properties exhibited by nanoclay and multi-walled carbon nanotubes, providing valuable insights into their unique physical and chemical characteristics. It also explores the methodologies adopted for their dispersion and the underlying functionalities within geopolymer composite. The review highlights advanced imaging and characterization techniques essential for understanding surface and mechanical properties. The review compares imaging techniques (scanning electron microscopy, transmission electron microscopy, helium ion microscopy, and atomic force microscopy), emphasizing their importance in characterizing mechanical properties of nanocomposites. A detailed discussion on the fresh and hardened mechanical properties, specifically compressive and flexural strength, of geopolymer concrete incorporating nanoclay and multi-walled carbon nanotubes is also included. Addressing key challenges and offering perspectives on future developments in the realm of geopolymer concrete, this review serves as a comprehensive exploration of the subject.