The State of the Industry

Typically, the term fiber reinforced polymer (FRP) composite is used to describe product applications in the aerospace, military or recreational industries, (e.g. skis, boats, race cars, or golf clubs). However, over the last twenty-five years, the civil infrastructure industry has been conducting continual testing and multi-million dollar project applications of FRP composite materials. Even though the other abovementioned industries have remained the primary consumers, the use of FRP composites in civil infrastructure is fast becoming a major contender. …

When we think of bridge health evaluation, the traditional means and methods have been inspection by engineers in the field and ratings based on loading assumptions. Bridge inspectors are the original non-destructive evaluators, using observation and diligent records to establish how a bridge is performing during its life cycle. The term Non-Destructive Evaluation (NDE) has a greater implication, though; we are doing more than a visual evaluation. …

Steel Joists and Deck Summary

As Building Information Modeling (BIM) continues to progress through the steel design and construction industry, showcasing its many benefits to the building project and its owners, demand for BIM information continues to increase. …

Steel fabricators have been using three dimensional models to detail structural steel for many years now. In many modern shops, all information required for the fabrication of a project is included in the detailed model, including dimensional information, material grades, piece marks and specification of welds. …

The definition of high strength concrete continues to change. This change occurs as the art of achieving a particular strength is reduced to practice, and the structural requirements push at the edge with needs for higher strength. One such example is the CN Tower in Toronto, with its required strength in 1976 of 5000 psi. At that time, this was difficult to achieve. Today 5000 psi concrete is routinely used and produced without special precautions. …

ASTM A500 has been the preferred material specification in the United States for cold formed, welded carbon steel hollow structural sections (HSS) since the late 1970s. In April of 2013, a new material specification, ASTM A1085, was released for steel tubes used in structural applications. …

The most important concrete property in the ACI 318 Building Code is compressive strength. This reflects the notion of using concrete as a strong material against compressive stress in structural members. Tensile forces are expected to be carried by prestressing or reinforcing steel. These fundamental structural design concepts of putting concrete in compression and steel in tension have largely worked very well. …

Insight into the new Limit Design method for special reinforced masonry shear walls – what it offers, how it was developed, and a glimpse at possible future developments.

“Limit Design is a bold step for masonry engineering and it marks it as an even more significant structural material.” That may be my favorite comment from my tenure as the MSJC Chair. It came upon the successful balloting and adoption of the new Appendix C – Limit Design of Masonry. …

Disproportionate collapse of structures continues to be an exciting topic in structural engineering, given its public safety implications, philosophical aspects, technical challenges, and opportunities for designers to expand their technical skills while proposing unique solutions. Research is actively underway in the US and many other countries, in both university and government laboratories, and technical sessions on disproportionate collapse at recent Structures Congresses have been lively and well-attended. …

Cross Laminated Timber (CLT) is a flexible building system suitable for use in all assembly types (e.g., walls, floors, and roofs). Made from industrial dried lumber stacked together at right angles and glued over their entire surface, it is an exceptionally strong product that retains its static strength and shape, and allows transfer of loads on all sides. Panels are prefabricated based on the project design, and arrive at the job site with windows and doors pre-cut. Although size varies by manufacturer, they can be as large as 54.1 x 9.7 x 1.6 feet and include 3, 5, 7, or more layers. …