Title: Sustainable Concrete Using Seawater, Salt-Contaminated Aggregates, and Non-Corrosive Reinforcement

Author(s): Antonio Nanni

Publication: CRC

Volume:

Issue:

Appears on pages(s):

Keywords: seawater, sustain, non-corrosive, aggregate, GFRP, steel, reinforce

DOI:

Date: 1/10/2015

Abstract:
The research project “SEACON: Sustainable concrete using seawater, salt-contaminated aggregates, and non-corrosive reinforcement” addresses the issue of sustainability from the perspective of the construction material most used worldwide. This 2.5-year project started on October 1, 2015. It was proposed and carried out by a transnational consortium of six partners and three collaborators including two academic institutions, six companies, and a department of transportation. During the course of the project, a fourth collaborator joined the consortium. The goal of SEACON is to promote the use of best practices in both the production of concrete and reinforced concrete (RC) structures by implementing alternative materials. The aim is to reduce the use of critical resources by replacing them with alternatives that can be chloride-contaminated coupled with non-corrosive reinforcement. This approach would extend the affordability and sustainability of constructed elements under aggressive environmental conditions without affecting their longevity and durability. The three overarching objectives of the research program are: • to confirm scientific evidence, through experimental work, that the presence of chlorides is not harmful to the properties of plain concrete; • to prove, through laboratory studies, the successful use of composite (glass fiber reinforced polymer – GFRP) and stainless steel reinforcement in concrete made with seawater, salt-contaminated aggregates, and high-chloride content cement; and, • to demonstrate this technology by means of two field prototypes, incorporating commercial design, while developing model specifications and guidelines to be proposed for adoption to national and international standard-writing agencies. The work plan was subdivided into seven Work Packages (WPs), of which five dealt with technical issues and two with dissemination and management, respectively. Laboratory and analytical work, including LCC/LCA studies, were conducted, and the technical results have been made available to the public via the internet (see http://seacon.um-sml.com/) as well as a number of presentations at national/international conferences and peer-reviewed publications in conference proceedings and journals. As important, the laboratory results made possible the planning and execution of the two field demonstrations that will be monitored beyond the duration of the SEACON project. The first demonstration is an open culvert project undertaken in Italy that was constructed during the last week of November 2016 along Motorway A1, near the city of Piacenza. Three concrete mix designs were considered (traditional concrete, concrete mixed with seawater and concrete produced with recycled asphalt pavement) in combination with different types of reinforcement (black-steel, GFRP, and stainless steel rebar’s). The second demonstration is the vehicular five-span bridge currently under construction in Homosassa, Florida (start date January 2017, expected end date December 2018). The bridge was designed by the Florida Department of Transportation for Citrus County, the owner, and includes a number of innovations that make it unique. SEACON technology was used in the bulkhead caps (made of concrete with seawater) and the gravity walls (made of concrete with recycled aggregates). All these elements were reinforced with GFRP. Both demonstrators served as the testbed for comprehensive and detailed LCC/LCA studies that have proved the viability of the technologies investigated in the project. Additionally, they provided the opportunity for developing the drafts for a new generation of construction and design specifications.