A comprehensive review on dispersion techniques of nano-SiO2 in concrete matrix
摘要
Advanced concrete structures require high performance materials with excellent mechanical and durability properties. One of the most effective ways to improve the performance of advanced concrete structures is nanomaterials. Nanomaterials such as nano-SiO2, nano-TiO2, nano-graphene oxide, carbon nanotubes, nano-alumina, and nano-ferric oxide is incorporated to improve the qualities of cementitious composites. Apart from the benefits, nanoparticles added to the concrete matrix are difficult to disperse. Dispersion of nanomaterials in concrete matrix plays a key role in enhancing concrete strength and durability properties. In past few decades significant amount of research has been conducted on incorporating nanoparticles in cementious matrix but the ideal method for nanoparticle dispersion remains uncertain due to limited research in this area and a lack of comprehensive understanding. This review paper aims to address these gaps by focuses on the dispersion of zero-dimensional nanomaterial in a cementitious matrix to better understand the appropriate dispersion technique for enhancing concrete properties. The study investigates the application of nano-SiO2 dispersion techniques in the concrete matrix, with particular attention to ultrasonication, dry mixing, wet mixing, and surface modification approaches. The review’s findings indicate that the optimal concentration of nano-SiO2 is between 0.5 and 4%, at which concrete properties were significantly improved. In cementitious matrix, the colloidal form of nano-SiO2 outperform the powder form and provide better dispersion. Wet mixing combined with ultrasonication works better when it comes to effectiveness, health concerns, and performance of concrete. In addition, it was found that the superplasticizer performs better as dispersion agents.