Self-healing Coatings for Steel-reinforced Infrastructure

EPA Grant Number: SU835699
Title: Self-healing Coatings for Steel-reinforced Infrastructure
Investigators: Sakulich, Aaron , Peterson, Amy
Institution: Worcester Polytechnic Institute
EPA Project Officer: Hahn, Intaek
Phase: I
Project Period: August 15, 2014 through August 14, 2015
Project Amount: $14,982
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2014) RFA Text |  Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Built Environment , P3 Challenge Area - Materials & Chemicals , P3 Awards , Sustainability

Objective:

The United States is facing an unprecedented, and rapidly escalating, maintenance crisis. The more than $100 billion spent annually is not enough to keep infrastructure in a state of good repair. More funding, however, is only a temporary solution- it is widely acknowledged that new materials, with better durability, are the key to addressing this challenge. The electrochemical corrosion of rebar in steel-reinforced concrete is a major contributor to this maintenance crisis. One of the most popular methods of delaying the onset of corrosion is to use epoxy-coated rebar (ECR). Chips or cracks in the epoxy coating, which can be easily introduced during handling or at the work site, significantly reduce the effectiveness of this technique.

This proposal therefore focuses on developing, for the first time, self-healing coatings for rebar. Self-healing coatings based on three different healing mechanisms will be investigated. If successful, these coatings will lead to better, and more consistent, corrosion resistance in infrastructure. As such, maintenance would need to be carried out less frequently, reducing the amount of energy and materials consumed during construction; the amount of waste produced; and additional traffic congestion, which leads to wasted fuel and unnecessary CO2 emissions.

Approach:

Well-established interdisciplinary methods will be used to investigate self-healing coatings for rebar. These methods include synthesis and processing techniques for producing the coatings, mechanical property measurement and accelerated corrosion tests to ascertain the effectiveness of the coatings, and life-cycle analyses to determine the practicality of the coatings. The corrosion tests will be run on large-scale specimens that can easily be scaled up further. The effectiveness of the three different healing methods will be compared.

Expected Results:

In the short run, the applicability of three different self-healing systems as rebar coatings will be investigated for the first time. In the long run, self-healing coatings on rebar will be less likely to be damaged at the job site, and will enter infrastructure in good condition. The rebar will therefore be more completely protected from chemical attack, extending the life of any given infrastructure system and obviating the need for environmental and economically costly maintenance. As rebar is a primary construction material, the benefits of improved rebar durability would be significant.

Supplemental Keywords:

Waste minimization, civil engineering, chemical engineering, epoxy resin, benzotriazole, bismaleimide

Progress and Final Reports:

  • Final