Coating materials are considered one of the most antique materials of human civilization; they have been used for decoration and the protection of surfaces for millennia. Concrete structures—due to their permanent exposure to different types of environments and contaminants—require the use of coatings that contribute to its preservation by reducing the corrosion of its components (steel and aggregates). This article intends to introduce the principal causes of concrete deterioration and the coating materials used to protect concrete structures, including a summary of the coating types, their advantages and disadvantages, and the latest developments and applications. Furthermore, this paper also assesses brief information about the potential challenges in the production of eco-friendly coating materials.

If high-carbon fly-ashes are to be used, applications that are unaffected or improved by carbon content need to be identified. Currently, there are no applications for high carbon fly-ashes. One promising application is as a binder for iron ore pellets used, as blast furnace feed, to produce iron and steel. The objective of this project was to investigate the use of high-carbon fly-ashes as iron ore pellet binders. This is the first attempt to reuse high carbon fly-ash. Iron ore pelletization is a high volume application; during 1998 iron ore pelletization consumed 756,000 metric tons of the current binder, bentonite clay, which is similar in chemical composition to fly-ashes. The cost of bentonite is high because it must be shipped several hundred miles from the Western United States to Minnesota and Michigan's Upper Peninsula, while fly-ash has the benefit of being produced by power plants located within a few miles of iron ore pelletizing plants.

This paper assesses the behavior of mineral, epoxy (EP), solvent, and water-soluble coatings when exposed to salt and regular water for 28 days. Also, it evaluates the pull-off adhesion strength of the same coating materials applied to concrete slabs saturated with oil and water and dried with two different processes: air-dried for 28 days and air-dried for 14 days plus 14 days in the oven at 70 °C. Properties such as carbonation, water absorption rate, pull-off adhesion strength were evaluated for all coatings, and tensile strength, Young’s modulus, and elongation percentage were calculated for mineral coatings. According to the results, the EP coating showed the best performance with the highest pull-off adhesion strength (2.55 MPa) and lowest absorption rate, about 0.02 ± 0.002 g/m2 day in saltwater and 0.03 ± 0.002 g/m2 day in regular water. In addition, EP coatings also presented the lowest carbonation rate and the highest suppress ratio. The excellent performance of epoxy coatings is mainly due to their low porosity and the ability to decrease chloride diffusion, making them better than other types of coatings investigated in this study.