Center for Marine Materials
Director: Richard Granata, Ph.D.
About the Center
All ocean and mechanical engineering department activities pertaining to materials are organized and accomplished through the Center for Marine Materials which is the only organized academic unit in the country dedicated specifically to the study of marine materials and corrosion. Flowing natural sea water is available in a laboratory setting at the oceanfront Center for Marine Materials Laboratory. The two required undergraduate materials courses (EOC 3200 and EOC 4240) provide instruction regarding the fundamental chemistry and physics of materials and interface these topics with aspects of the marine environment so that engineering materials alternatives and choices for ocean and related service are understood. This theme progresses through graduate studies with courses in corrosion and corrosion control, physical metallurgy, fracture and failure analysis, fracture mechanics, and composite materials.
Research Areas Overview
Corrosion and Corrosion Control of Steel in Concrete
Corrosion of reinforcing steel in concrete and the resultant cracking and spalling of concrete constitutes the single most costly form of infrastructure deterioration in developed countries. This arises from salt (chloride) contamination of the concrete in conjunction with either deicing of northern transportation systems during winter months or marine exposure, or both. While there are numerous corrosion mitigation alternatives for new (non-salt contaminated) structures, cathodic protection and electrochemical chloride removal have emerged as singularly appropriate for ones already affected. However, the high specific resistivity of high performance concrete presents particular difficulties in application of these technologies. Corrosion propagation of the steel reinforcement under natural and modestly accelerated conditions are also being investigated. This is being done to better understand the parameters that affect the corrosion propagation stage (including the time to crack, ratio of corroding site length to concrete cover, resistivity of the concrete, moisture content). For new structures the use of corrosion resistant alloys is sometimes considered, our lab has been testing several corrosion resistant solid metallic reinforcements.
Sponsors: Federal Highway Administration, National Cooperative Highway Research Program, Florida Department of Transportation and IZA.
|Eanode effect, anodes at 9 m, h=10 m, 1% coating defective (left) and 10% coating defective (right)|
Durability of Composites exposed to Seawater
Modeling of Corrosion Processes
Cathodic protection modeling of the throwing power of intermediate anodes in a ballast tank. For systems consisting of coated steel that also include high strength fasteners (e.g. Monel K-500 bolts), it is important to know cathodic polarization levels for both corrosion protection (both at the fastener and coated steel) but also to avoid coating damage and hydrogen embrittlement (particularly at the fastener). Computational efforts were conducted to better understand polarization levels obtained under various conditions for a system with zinc/intermediate anodes, coated steel proximate to Monel K-500 bolt.
Collaboration with the University of Virginia under a project for the Office of Naval Research.
|Potential map for Eanode ranging -1.1 V (top row), -1.V (center row), -0.9 bottom row. All cases had h= 10 m, conductivity 2 S/m, anodes at 9 m from the center of the tank. Left column 1% coating defective and right column 10% coating defective.|
Durability of Concrete Structures
Chlorides from the solution surrounding reinforced steel concrete structures (typically bridges) exposed to marine environment could eventually cause corrosion of the reinforcing steel. Cores obtained from the field and/or outdoor exposed laboratory specimens are being used to better understand the transport of chlorides into high performance concrete. The cores are sliced or milled to various depths to obtain the chloride profiles, from which the apparent diffusivity is calculated. In addition, rapid migration test and resistivity characterization as the concrete ages (both natural and accelerated curing) are also being performed on concrete mixes relevant to FDOT.
Sponsor: Florida Department of Transportation