The Improvement of Durability of Reinforced Concretes for Sustainable Structures: A Review on Different Approaches

Abstract

The topic of sustainability of reinforced concrete structures is strictly related with their durability in aggressive environments. In particular, at equal environmental impact, the higher the durability of construction materials, the higher the sustainability. The present review deals with the possible strategies aimed at producing sustainable and durable reinforced concrete structures in different environments. It focuses on the design methodologies as well as the use of unconventional corrosion-resistant reinforcements, alternative binders to Portland cement, and innovative or traditional solutions for reinforced concrete protection and prevention against rebars corrosion such as corrosion inhibitors, coatings, self-healing techniques, and waterproofing aggregates. Analysis of the scientific literature highlights that there is no preferential way for the production of "green" concrete but that the sustainability of the building materials can only be achieved by implementing simultaneous multiple strategies aimed at reducing environmental impact and improving both durability and performances.

Keywords: alternative binders; concrete durability; design strategies; rebars corrosion.

Figure 1

Different approaches to self-healing.

Figure 2

Average value of the concrete cover thickness as a function of the type of concrete (OPC = Portland cement; GGBS = ground granulated blast furnace slag; water/binder = 0.45) and the type of bar that guarantees a service life of 100 years in the splash zone, assuming a target probability of failure of 10%.

Figure 3

Water uptake as a function of the square root of time for mortars containing siliceous sand (Sand) and rubber grains from end-of-life tires (Rubber). Larger (L) and smaller (S) granulometric fractions of rubber have been separately use.