Keith Fortune

Bio: Keith Fortune is an academic researcher from Montana State University. The author has contributed to research in topics: Durability & Thermal spraying. The author has an hindex of 5, co-authored 5 publications receiving 556 citations.

Investigating longevity of corrosion inhibitors and performance of deicer products under storage or after pavement application.

Abstract: This study evaluated the longevity of corrosion inhibitors and the performance of inhibited deicer products under storage or after pavement application. No significant degradation of corrosion inhibitor or loss of chlorides was seen during the months of field storage. The fate and transport of the inhibitors differed from those of the chlorides, in which dilution by precipitation and likely wicking of the deicer into the pavement and the top snow layer contributed to the loss of inhibitor and chlorides. The accelerated UV-degradation lab study found little degradation of GLT and FreezGard inhibitors but significant degradation of CCB inhibitor. While these inhibitors demonstrated their effectiveness in corrosion inhibition, they showed no side benefits in deicer performance. No significant difference in anti-icing performance was observed between the three liquid deicers during the two storm events. All three liquid deicers worked effectively for anti-icing applications under the investigated conditions. It is unnecessary to implement any mixing for the liquid deicer tanks, other than immediately prior to the use of the liquid deicers to ensure uniform composition and minimize stratification. Without dilution by precipitation (the black ice event), the percent of chloride recovered from the pavement by day 4 was approximately 30%, 20%, and 50% for NaCl+GLT, CCB, and FreezGard respectively. Up to 80% of the CCB inhibitor was recovered from the pavement 4 days after the deicer application. While such residuals could be washed away by precipitation, their presence on the pavement could potentially be measured and considered when re-applying chemicals for snow and ice control. This project revealed that the relative corrosivity of deicer solutions on the field pavement differed from that in the lab.

Replacing thermal sprayed zinc anodes on cathodically protected steel reinforced concrete bridges.

Abstract: This research aimed to address questions underlying the replacement of arc-sprayed zinc anodes on cathodically protected steel reinforced concrete bridges and to develop a protocol to prepare the concrete surface for the new anode, through a combination of literature review, practitioner surveys, laboratory studies, and field investigation (Pier 9 of the Yaquina Bay Bridge, Oregon). Concrete with an equivalent electrochemical age of 5 to 45 years was found to have a reaction layer of ~1 mm. To achieve strong initial bond strength of new zinc to the profiled concrete surface, the current ODOT sandblasting operating configuration (#8 nozzle with high sand volume) is too aggressive and should be changed to #6 nozzle with low sand volume to achieve target RMS macro-roughness of 1.2-2.1 centi-inches and micro-roughness of 3.5-5 μm. It is recommended to adjust the anode removal and surface profiling based on the electrochemical age of the existing concrete. Wherever possible, large aggregates (e.g., diameters ¾ in. and bigger) should be avoided for exposure by surface profiling. For non-electrochemically aged concrete, the surface should be profiled to achieve a RMS macro-roughness of 1.1-1.8 centi-inches and 5-36% exposed aggregates. For existing concrete with relatively high electrochemical age (14 yrs), the surface should be profiled to achieve a RMS macro-roughness of 1.1-1.5 centi-inches and 44-55% exposed aggregates. The following recommendations were made for old anode removal and surface preparation before new anode application: use a reasonably low air pressure and a reasonably hard and dense abrasive material for sandblasting; have a reasonably thin coating per pass during arc-spray operations; and have a slightly thinner overall Zn coating layer (15-17 mils vs. the currently used 17 mils). It is also desirable to have concrete with good surface cohesion strength and a minimum of 150 psi initial bond strength. For existing concrete with an equivalent electrochemical age of more than 8 years, the reaction layer should be completely removed prior to profiling and arc spraying (e.g., 4 mm grinding).

High-performance fiber-reinforced concrete: a review

Abstract: In recent years, an emerging technology termed, “High-Performance Fiber-Reinforced Concrete (HPFRC)” has become popular in the construction industry. The materials used in HPFRC depend on the desired characteristics and the availability of suitable local economic alternative materials. Concrete is a common building material, generally weak in tension, often ridden with cracks due to plastic and drying shrinkage. The introduction of short discrete fibers into the concrete can be used to counteract and prevent the propagation of cracks. Despite an increase in interest to use HPFRC in concrete structures, some doubts still remain regarding the effect of fibers on the properties of concrete. This paper presents the most comprehensive review to date on the mechanical, physical, and durability-related features of concrete. Specifically, this literature review aims to provide a comprehensive review of the mechanism of crack formation and propagation, compressive strength, modulus of elasticity, stress–strain behavior, tensile strength (TS), flexural strength, drying shrinkage, creep, electrical resistance, and chloride migration resistance of HPFRC. In general, the addition of fibers in high-performance concrete has been proven to improve the mechanical properties of concrete, particularly the TS, flexural strength, and ductility performance. Furthermore, incorporation of fibers in concrete results in reductions in the shrinkage and creep deformations of concrete. However, it has been shown that fibers may also have negative effects on some properties of concrete, such as the workability, which get reduced with the addition of steel fibers. The addition of fibers, particularly steel fibers, due to their conductivity leads to a significant reduction in the electrical resistivity of the concrete, and it also results in some reduction in the chloride penetration resistance of the concrete.

Bioinspired Surfaces with Superwettability for Anti-Icing and Ice-Phobic Application: Concept, Mechanism, and Design

Abstract: Ice accumulation poses a series of severe issues in daily life. Inspired by the nature, superwettability surfaces have attracted great interests from fundamental research to anti-icing and ice-phobic applications. Here, recently published literature about the mechanism of ice prevention is reviewed, with a focus on the anti-icing and ice-phobic mechanisms, encompassing the behavior of condensate microdrops on the surface, wetting, ice nucleation, and freezing. Then, a detailed account of the innovative fabrication and fundamental research of anti-icing materials with special wettability is summarized with a focus on recent progresses including low-surface energy coatings and liquid-infused layered coatings. Finally, special attention is paid to a discussion about advantages and disadvantages of the technologies, as well as factors that affect the anti-icing and ice-phobic efficiency. Outlooks and the challenges for future development of the anti-icing and ice-phobic technology are presented and discussed.