Nano-SiO2 contribution to mechanical, durability, fresh and microstructural characteristics of concrete: A review

Long-term durability of concrete has been of interest for researchers in past decades, and throughout their numerous research endeavors, they have tried to improve durability with the application of different methods. One technique is the integration of a new material into the concrete. One material that has attracted great attention of researchers is nano-SiO2 (NS). Its considerable performance in the enhancement of durability properties of concrete and mortar provides reasonable specifications satisfaction for scholars. In this paper, important durability characteristics of concrete, including the chloride ion penetration, electrical resistivity, water penetration, water absorption, the pore size distribution, the carbonation, the sulfate resistance, frost resistance, shrinkage, and thermal properties were explored. Additionally, the effects on the microstructure of concrete and mortar in the previous studies were discussed. Mechanical properties, such as compressive strength, flexural strength, tensile strength, and abrasion resistivity were also investigated in the past and most recent papers.