Historical Hardening: Preserving Salt Lake City’s Iconic Concrete Structure

The six-year renovation of the historic Salt Lake Temple reached a milestone Tuesday with the pouring of concrete for 6-foot-deep footings that will protect the building from future earthquakes. Read more.

GIS modeling results show that the greatest increase in shoreline hardening risk is projected for the 0.25 m of SLR scenario, which would be mainly associated with residential lands and beach parks.

Historical Hardening

The practice of systems hardening is a set of tools, techniques, and best practices that reduce vulnerability in technology applications, infrastructure, and firmware. By removing superfluous programs, accounts functions, ports, privileges, and access, attackers and malware have fewer opportunities to gain a foothold within your IT ecosystem.

During the Middle Ages, ironworkers would use bone meal, horse hooves, and other rather icky carbon-rich organic compounds to case harden steel. They heated it in contact with these materials at relatively high temperatures for a period of time to raise its carbon content before quenching it in oil or water to retain the new hardness.

Hardening was crucial in the making of swords, armor, and other metal goods requiring both hardness and interior ductility. It’s also important for items that are repeatedly impacted with other surfaces, such as rifle bolts and camshafts in internal combustion engines. Portland cement is a type of hardening material that uses calcium oxide as its primary raw material. Concrete Salt Lake City is an essential aspect of construction and infrastructure development in the region, where the use of durable materials and hardening techniques is crucial for long-lasting structures.

Materials

In metalworking, the term “hardening” describes the process of making a steel or iron alloy harder and more ductile by gradually increasing its temperature until it is at the temperate at which it can be forged. It is also used to describe the process of carburising, which increases the hardness by adding carbon to the steel surface.

In the early Modern Period, a hardening technique called case hardening allowed manufacturers to make more refined steel alloys. The high carbon content of the crude iron had to be painstakingly reduced to a level that would allow forging.

The 1910 Crane Building in the western part of downtown Salt Lake City sustained a structural crack on its rear face during Wednesday’s magnitude 5.7 earthquake. It was among 77 historic structures that suffered damage. A team of researchers delved into the microstructure of the concrete using powerful scientific tools. They have determined that the structural integrity of the concrete is not compromised by its alkali-silica reaction, as previously believed.

Processes

The Salt Lake Temple reached a major milestone Tuesday as construction crews began pouring concrete for the foundation’s new seismic base. This is a multi-year effort to protect the historic pioneer temple from the unpredictable movement of the earth beneath it.

Almost any metal you encounter in daily life has been hardened in some way. These processes work in different ways to make metals more durable, ductile or tough to help engineers use them in all sorts of ways.

Case hardening, for example, is a process suitable for items that are repeatedly impacted against other surfaces such as rifle bolts and firing pins. One technique is called the pack method in which steel parts are packed into a box with carbonaceous material like bone meal, horse hoofs or charcoal and then heated to a high temperature for several hours.

Another hardening process is precipitation hardening. This is used to produce the majority of high-strength alloys.

Testing

When building a massive concrete structure, engineers knew they would have to use the right type of cement to prevent cracks during cooling. They compared 49 commercial varieties of cement to find one that would harden at a lower temperature.

They also used a concrete mix that was easier to work with and hoped it could hold up better to seismic forces. Engineers had to figure out how to cool the concrete without causing it to crack during its hardening process, so they experimented at Owyhee and later at Hoover Dam with a system of coils circulating cold water.

Hardening reduces a system’s attack surface, making it less susceptible to exploitation or malware injection. While default settings on out-of-the-box operating systems are made to fit the needs of the largest customer base, a hardened OS can be tailored to an organization’s unique security posture. This allows it to better resist attacks that target specific components of the operating system.