If you're in the construction industry, you must be fairly aware of the structural magnificence of the Eifel Tower. A 1,063 feet high tower built using 18,000 pieces of steel. And all the pieces joined together using 2.5 million thermally assembled rivets. The construction of Eifel Tower was completed in the year 1889. Comparing the complexity of the structure from the year of its building makes it a master art of steel construction. The 10,000 tons of steel held straight using rivets since 1889, gives us an idea of how effective riveted steel connections can be.
The Eifel tower was built in the 19th century and it is still the same with just a little maintenance and paint jobs once every few years. Riveted connections in steel construction are used by many architects and mechanical engineers to join two steel pieces. Riveted connections were the best-found fit for the construction of airplane frames. This was because aluminum was used to build the plane's structure, as it was the lightest metal (to decrease the weight during the flight and tolerate the pressure from the winds and speed). Aluminum rivets are used to connect two structures of the plane as rivets are more enduring at such high speeds. But not everywhere do rivets perform the same as they did with the Eifel Tower.
What are the Advantages of Using Rivets for Steel Structures?
Rivets are used for strengthening different types of steel structures and to provide stability in complex structures created using more than 10 pieces of steel. Rivets are a popular fastening method among workers in the steel construction industry. The advantages it provides for construction of bridges and cell-phone or electrical towers makes it an advantageous fastener for steel construction.
1. Cost Effectiveness
Rivets are a cheap alternative to welding and metal adhesives. They save the cost of electricity that is required in large amounts for welding connections. There is no need for any special materials for the connection, unlike welding, which uses a hot metal adhesive to connect the steel members. The small size of the rivets allows transportation of larger quantities at once, thus saving the cost of transportation too.
2. Increases Production Output
Welding requires the preparation of both the pieces to be connected. The welding process also takes a lot of equipment to weld together and finish it by grinding the extra waste residue left on the joints. This increases the production cost and decreases your daily productivity. Riveting a joint, on the other hand, takes much lesser equipment and there is negligible waste residue left after the joint has been riveted. This decreases production cost and increases the profits of production.
3. Flexibility in Design
Rivets are manufactured in different shapes and structures according to the needs of construction. They are available in different materials that are chosen by the engineers for their steel construction design. Oval-headed, brazier headed and tubular rivets are some common designs and have different strength and tolerance values. The rivets can be painted or polished to match the main working structure. You can have different metal combinations for different pressures and metal thicknesses.
Solid steel rivets are highly durable. They are resistant to corrosion, moisture and even chemicals. Most of the rivets used in steel construction are made out of highly resistant metals and alloys such as galvanized steel, nickel, titanium and aluminum-based alloys, which increases the tolerance to high pressures and shear load. The anti-corrosive properties also increase the life of the part being joined together.
5. Easy Inspection and Maintenance
Inspecting and maintaining welded structures takes a longer time than rivets. Welded joints need a closer look to find out the wear and figure out the life of the joints. If a welding has worn off, the equipment has to be installed all over again and the welding process continues. Rivets, on the other hand, do not require a finer inspection. And the worn rivet can be easily reinstalled with minimum equipment like a hydraulic riveting machine or a simple hammer.
What are the Disadvantages of using Rivets for Steel Structures?
Although rivets can be highly durable for steel constructions, it has some disadvantages when compared to welded joints.
1. More Work Force
Riveting requires more workforce. A total of 4 people are required to complete the process. The buck-tail of the rivet is supposed to be heated until its red hot. One person is required to stand between the riveting position and the person who is heating up the rivets. The red-hot rivets are then passed on to the people fitting the rivets. Two people are required to hold the rivet in place and hammer it with full force to deform it and seal it from both the sides. This increases the cost of manpower required.
2. Higher Structural Weight
Let’s go back to the Eifel Tower. The 10,000 tons of weight is the result of 2.5 million rivets. Rivets are fully metal parts with their own weight. They surely do weigh higher than the welding joints. This adds extra weight to the structure you're building. It can be a hindrance to the efficiency of rivets as they might even sometimes get affected by the weight of other riveting joints.
3. Lack of Aesthetic Finish
Welded joints have a more finished touch to their appearance. The welded area cannot be easily noticed even from a short distance. Welders grind the excess material from the joints and keep it in level with the two adjoining parts. On the other hand, rivets can be seen from far off and protrude from the steel structure. It decreases the aesthetic appeal of the structural design.
Steel is used in almost all manufacturing or infrastructure industries as a temporary and permanent solution. If you're into steel construction, you’re fairly knowledgeable about the importance of steel, welding, bolts, and rivets. Northern Weldarc Ltd., provides structural steel for construction and also the equipment to work with the steel and build something magnificent.