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The effectiveness of aesthetic coating systems for steel bridges was studied. Twelve 2-coat, 3-coat, and duplex coating systems were selected and subjected to a series of accelerated weathering and mechanical tests to determine their performance. The performance evaluation was made by considering gloss and color retention, coating discontinuities,...
Context in source publication
Context 1
... liquid coating systems in this study were 2-or 3-coat coating systems that were applied to non-galvanized steel plates. All coatings were mixed per manufacturers' recommendations using a pneumatic mixer shown in Figure 45. If allowed and needed, coatings were thinned per manufacturers' recommendations and with the manufacturers-recommended thinners. ...
Citations
... As a corrosion protection technique, painting has been found to prolong the life of steel superstructures (Chong, 2004;FHWA, 1997aFHWA, , 2001Ghorbanpoor et al., 2013;Hopwood and Oberst, 1992;Oregon DOT, 2016;Roberts and Shepard, 2000;Zayed et al., 2002). However, highway agencies have been grappling with the question of when to paint the steel superstructure and which level of paint intensity to apply. ...
... This can be done to characterise the complex responses of various coating systems in the real world. Also, future research could replicate the work done by Ghorbanpoor et al. (2013) at different environments to investigate the effectiveness of coating systems that differ by the number of coatings, material base, gloss and colour, and the performance could be evaluated on the basis of criteria including colour retention, coating discontinuities, rust creepage, coating adhesion, overall longevity and the initial and life cycle costs. Also, the current visual ratings can be inadequate/ misleading due to certain coating problems, which can be hidden under the coating. ...
A bridge paint schedule is a set of treatment types (overcoat, recoat, spot repair) and timings. Age-based or
performance-based scheduling decisions for painting steel bridge superstructures are often made using expert
opinion, continuation of historical practice or explicit optimisation. Optimisation is the preferred mechanism because
it yields solutions that are not only data based but also objective and defensible. The information needed as inputs
for optimising painting application decisions (long-term paint scheduling) includes the agency and user costs
associated with painting projects and the long-term performance of bridge paint coats or the painted steel
component. This paper presents a synthesis of available literature on concepts that have been or could be applied to
develop these inputs. The paper also documents the painting decision trees and tables that have been developed in
the literature and describes past methodologies that have been used to develop these decision support tools.
... Hence, to specify an appropriate coating system that is known (through testing and validation) to perform well is more important than ever. Specification of coatings by generic type or using an equivalent approach can lead to disappointing results (Ghorbanpoor et al. 2013). ...
Departments of transportation (DOTs) currently use the conventional three-coat system as the predominant choice for the corrosion protection of steel bridge structures. Eliminating one step in the coating process could potentially save time and cost associated with lane closures and traffic control costs. This research paper evaluates several two-coat systems based on the zinc-rich primer and polysiloxane topcoat technology. All samples were conditioned and coated in a state-of-the-art, climate-controlled paint booth, simulating common field ENvironmental CONditions (ENCON) (ENCON 1: 25 °C/50% RH, ENCON 2: 10 °C/40%RH, and ENCON 3: 32°C/80% RH). Accelerated weathering tests were performed on 435 coated samples (scribed and unscribed). Regardless of the ENCON considered, the performance of the two-coat system is very comparable to the three-coat system. This coating technology offers much improved performance with quicker set time and better adhesion pull-off strength. Considering its durability and ease of application, this two-coat system can be attractive to other public and private agencies to enhance and extend the service life of steel structures.
... Material costs vary depending on the location and size of a project. Considering only the material cost by volume or weight may not offer the best representation of the actual cost for a project [12]. ...
... Properties Comparison of Collected Data: two coat and three coat system[12].A one page questionnaire has been prepared to solicit information and feedback. All 18 neighboring state DOTs have been contacted for the survey. ...
Departments of Transportation currently use the conventional three-coat system as the predominant choice for the corrosion protection of steel bridge structures. Eliminating one step in the coating process could potentially save time and the cost associated with lane closures and traffic control costs. Available field performance data for the two-coat system, zinc-rich and a polysiloxane top coat, is somewhat limited. To set the stage for any potential field applications, a comprehensive testing approach is presented and conducted in this report. This experimental work evaluates several two-coat systems, based on the zinc-rich primer and polysiloxane top coat technology. All samples were conditioned and coated in a state-of-the-art, climate-controlled paint booth chamber, simulating common field environmental conditions (ENCON) (ENCON 1: 25 °C/50% RH, ENCON 2: 10 °C/40%RH, and ENCON 3 :32°C/80% RH). Severe accelerated weathering tests were performed on scribed and un-scribed panels. Test results include accelerated corrosion tests, dry film thickness, adhesion, chipping resistance, UV/Condensation, abrasion resistance, fresh and salt water immersion tests, and flexibility of the coating systems. Overall and regardless of the ENCON considered, the performance of the two-coat system is very comparable to the three-coat system. This coating technology offers much improved performance with quicker set time and better adhesion to steel structures. Considering the lower cost and ease of application, this two-coat system can be attractive to other Departments of Transportation and will enhance and extend the service life of the infrastructure assets.
