My wife thinks that my driving skills are poor. She is not entirely wrong in this opinion. Whenever I am on a long drive or I am driving in an unfamiliar area, my eyes tend to stray from the road and examine any bridge or sign structures I come upon. If you do the same […]
When a large-scale bridge is in need of significant reconstruction, many factors should be considered prior to initiation of the project. Part of this particular reconstruction involved repainting of the structural steel on a 40-foot-wide lift bridge that had a total length (including approaches) of 2,877 feet, with a main span of 418 feet. The
Investigating Failure: Considerations for Reconstruction of a Bridge Exhibiting Staining Read More »
Weathering steel, often referred to by the genericized trademark COR-TEN steel, is a group of steel alloys developed to form a stable corrosion-resistant surface after several years exposure to weather, potentially eliminating the need for painting in many environments. U.S. Steel (USS) holds the registered trademark on the name COR-TEN, which refers to the two
Weathering Steel – Use and Preparation When Left Uncoated and When Coated Read More »
Galvanizing is the application of a zinc layer to steel by a variety of methods such as hot dip, continuous or electro-deposition. In many instances galvanized steel is not painted since the service life of galvanizing alone typically exceeds that of conventional protective coatings. When paint is applied to galvanizing it often is referred to
Preparing and Painting Galvanizing Read More »
Background/Introduction The AASHTO/AWS D1.5M/D1.5 Bridge Welding Code: 2015 published by the American Welding Society (AWS) covers the welding requirements for The American Association of State and Highway Transportation Officials (AASHTO) welded highway bridges fabricated from carbon and low-alloy constructional steels. This code covers welding fabrication requirements applicable to welded highway bridges. The code is applicable
Changes to the 2015 Edition of the AASHTO/AWS D1.5 Bridge Welding Code Read More »
Introduction Surface profile is defined as a measurement of the maximum peak-to-valley depth generated by abrasive blast cleaning and impact-type power tools. These operations effectively increase the surface area and provide an “anchor” for the applied coating system. The surface profile depth must be compatible with the total coating system thickness; typically, the thicker the
Surface Profile Measurement Options on Rough/Pitted Steel Surfaces Read More »
Nearly every structure is an assemblage of individual parts or members that must be fastened together, usually at the ends of the member, by some means. Welding is one such means and is quite effective. The other usual means is to use fasteners such as rivets or bolts. This article is concerned with bolting, in
Slip Coefficient of Bolted Connections: What is it and Why is it Important? Read More »
Before describing the difference between inorganic zinc-rich coatings and organic zinc-rich coatings, an explanation of galvanic protection is necessary. Zinc-rich coatings are used to protect steel substrates from corroding by employing some barrier protection but primarily sacrificial or cathodic protection. A corrosion cell contains four elements (oxygen is assumed to be present): anode, cathode, metallic
Inorganic Zinc-Rich Primers vs. Organic Zinc-Rich Primers: What’s the Difference? Read More »
Introduction The American Association of State Highway and Transportation Officials (AASHTO) is a nonprofit, nonpartisan association representing highway and transportation departments in the 50 states, the District of Columbia, and Puerto Rico. It represents all five transportation modes: air, highways, public transportation, rail, and water. Its primary goal is to foster the development, operation, and
AASHTO NTPEP DataMine for Structural Steel Coatings – Its Value and Use Read More »
Rather than describe a failure that has already occurred, this article addresses key steps to follow when painting bolted connections in order to prevent failures from occurring by focusing on surface preparation and painting practices that have been used successfully on bolted bridge connections such as splice plates and gusset connections for new construction projects