The key to accelerated steel bridge fabrication is seamless teamwork between the fabricator, owner, engineer, and contractor--and NSBA’s brand-new guide is designed to help you do just that.  

Accelerated Steel: Achieving Speed in Steel Bridge Fabrication describes how each of these roles affects critical shop support activities, which can make or break the fabrication schedule. This guide describes the ideal schedule for every step of fabrication as well as the responsibilities for owners, designers, and general contractors.  Learn more.

The use of steel provides great flexibility in the design of girder flanges, webs, stiffeners, field splices, and cross-frames. However, designers are routinely confronted with repetitive design decisions regarding material thickness and sizes for the routine steel I-girder bridges. In fact, two designers could design a steel I-girder bridge for the exact same span lengths and bridge width with girders that have completely different flange and web sizes, as well as differing cross-frame layout and member designs.

The objective of this project is to develop straight steel I-girder bridge standards for single-span bridges as well as two-, three-, and four- span arrangements that are optimally cost-efficient when considering design, material selection, fabrication, and construction. Achieving this objective would make the I-girder bridge design process faster, and as a byproduct of the careful consideration of sizing members, would also make the fabrication process more efficient and cost effective.

These standards will optimize and standardize web, flange, stiffener, and field splice plate sizes that can be readily obtained by fabricators from typical mill plate widths and thicknesses. They will also provide cost-efficient diaphragm and cross-frame standards for the entire suite of identified bridges. Look for these standards later next year.

Bridges designed with uncoated weathering steel (UWS) are the least expensive and fastest-to-fabricate when compared to any other system. UWS reduces the time necessary to fabricate structural steel and offers the benefits of reduced cost, both in terms of initial fabrication and construction costs as well as long term maintenance costs (life cycle costs).

The Uncoated Weathering Steel Reference Guide provides guidance for bridge owners and designers on when it is appropriate to specify UWS in bridge applications.  It discusses how to design, detail, fabricate, construct, inspect, preserve, maintain, and repair weathering steel bridges. Download the guide today!

SpeedCore has proven that a shop-fabricated core system can slash construction time. Can a shop-fabricated, panelized structural floor system do the same?

The goal of this project is to create a modular floor system (primarily steel and mostly fabricated off-site) that can be erected 30-50% faster than traditional concrete-on-metal-deck systems. These panels could be lifted and quickly set in place with simple, optimized connections.

Designers and researchers are considering this challenge and working on solutions. For example, Ron Klemencic of MKA is working on applying shipbuilding technology to floor systems, while Northeastern University’s Jerry Hajjar, Iowa State’s Sam Easterling, and Johns Hopkins’ Ben Schafer are all looking for potential game-changing innovations.

SpeedCore has already proven to dramatically accelerate construction time by over 40% and AISC plans to issue a Design Guide this year. (See aisc.org/speedcore for more information on this innovative system, and see the March 2021 issue of Modern Steel Construction for more insight into the background of SpeedCore.)

Now, researchers, including Amit Varma at Purdue and Michel Bruneau at the University at Buffalo, are looking at further improvement and additional applications. In addition, the Charles Pankow Foundation, MKA Foundation, and the Steel Institute of New York are funding further fire testing on steel-beam-to-SpeedCore wall connections.

Well underway is an effort to determine an optimized set of asymmetric shapes based on likely usage in shallow floor system construction. These asymmetric shapes will have differently sized top and bottom flanges and are used to simplify construction and reduce floor-to-floor height by allowing floor systems to easily rest on the bottom flange rather than the top. (To see a similar example, check out the Girder Slab system, girderslab.com, which uses a custom asymmetric member referred to as a D-Beam.)

As part of his Milek Fellowship work, Matthew Yarnold of Texas A&M University is performing analytic work to develop optimized geometries for asymmetric shapes and testing them on large-scale prototypes. It’s anticipated that testing will begin in the summer of 2021.

The industry oversight group for this project includes Chris Garrell (AISC/NSBA), Chia-Ming Uang (University of California-San Diego), Tom Sabol (Englekirk Structural Engineers), Joe Zona (Simpson Gumpertz & Heger), Ronnie Medlock (High Steel), Duff Zimmerman (Cooper Steel), and Margaret Matthew (AISC).

What if we could use innovative connections to simplify design and construction and speed erection? What if those connections also created fixed end conditions that would make our systems more rigid with lower deflections and drifts under load? 

This project will consider how current fabrication and erection technologies could be leveraged to make such connections, as well as the potential role of castings, how automation could influence connection economics, dimensional control, fit-up issues, ease of design, and specific safety (OSHA) requirements for steel connections.

The utility and safety of traditional spray-on fire-resistant material (SFRM) applied to steel framing in buildings are well known. And yet offsite application of fire protection can create scheduling benefits for other trades and reduce the construction schedule. Fabricators in the U.K. and Europe have already begun using shop-applied intumescent paints with great success.

Differences in building codes and fire safety requirements have made shop-applied intumescents more time consuming and more expensive on domestic projects than on similar projects in other countries. However, new formulations show promise at overcoming those limitations.

AISC and member fabricator Thomas Steel are working together on a shop demonstration of a new intumescent paint from Sherwin Williams, which dries quickly and is resistant to damage during handling. In addition, fire testing is underway at UL Laboratories.

New Products
This month’s New Products section focuses on software packages, many of which include features that can help users achieve the goal of AISC’s Need for Speed initiative: to increase the speed at which a steel project can be designed, fabricated, and erected by 50% by the end of 2025. For more on Need for Speed, see aisc.org/needforspeed.

Augmented Approach
Augmented reality provides a tool for steel fabricators to improve their processes, and a university research team is developing a program to make it accessible to fabricators across the country.

Early Integration
Fabricators can benefit in myriad ways from an integrated steel delivery model.

Evolutionary Optimization
A discussion on parametric design and optimization of steel structures.

The Times, They've Always Been a-Changin'
What propels the speed of structural engineering? In a word: technology.

Against the Wind
A look at wind design considerations for the SpeedCore system.

Nearly 360 Degrees of Separation
Robotic structural steel fabrication equipment hasn’t reached “end all be all” status quite yet, but those early adopters who have integrated it into their shops have generally been pleased with the results.

steelwise
Intuitive Details
While constructability ultimately becomes the creator's concern, addressing it early via more intuitive detailing can create a scenario where it's not a concern at all.

Coat of Arms
KTA-Tator's new home is an homage to the company's coatings know-how and steel history.

Accelerated Welding: Part Two
Taking on the need for speed in welding applications.

Accelerated Welding: Part One
Taking on the need for speed in welding applications.

Augmenting Productivity
Augmented reality is showing potential for increasing productivity when it comes to designing and building steel projects.

SpeedCore: Seismic Advantages
What to know when considering a SpeedCore system for its seismic properties.

Inside Job
Transforming Seattle’s historic KeyArena into the new state-of-the art Climate Pledge Arena required the near-total demolition of the old structure and construction of a new one—all while keeping the roof and façade intact.

Driving Innovation
How can the steel industry drive true innovation?

Moving Bridges Forward
Corrosion-resistant steel bolts and built-up press-brake-formed tub girders are showing promise.

Super Fast, Super Tall
In a city known for the tallest buildings and fastest pace of life in the country, a supertall skyscraper opens early thanks to an innovative steel connection design and modeling process.

Core Value
The first in a multi-part series on SpeedCore covers what influenced the system, how it was developed, relevant research, design and fabrication considerations, and the reason for its name.

Structurally Sound
Fire—and Rescue