Steel structures

STEEL STRUCTURES

Concrete is one of the very important and widely used materials in modern building construction. However, steel, by virtue of its physical properties, emerges a major contributor to the fabrication of infrastructure required for smart cities.

 

1. SMART CITIES

Across the globe, cities are marching towards becoming smart cities. In the attempt, they are either coming out with unique solutions using existing infrastructure or are adopting eco-friendly and sustainable models to solve problems of traffic, drainage, commuting, accommodation, and the like.

Project Smart Cities is a visionary project of the Government of India for sustainable, high quality of life in terms of infrastructure, mobility and connectivity, technology, environment, availability of resources and overall living conditions and experience.

The government's Smart City initiative is an urban renewal programme to develop 100 such cities in the country. The move aims for a major facelift of the existing inadequate infrastructure, including roads, flyovers, airports, residential areas and city sewage systems. It also includes community areas such as parks, shopping centres, hospitals and schools. For structures that are intended to have at least a 100-year life cycle with minimal maintenance but are quick to complete, the answer lies in steel, whether it is underground, above ground or in buildings.

Buildings across the globe 'are steel intensive. In many landmark buildings, such as the Lotus temple in Delhi, stainless steel rebars used have a lifespan of about 300 years. Creating new smart cities or upgrading old cities is fastest and cost effective with steel structures.

The Tokyo Metropolitan Government's Bureau of Waterworks has used stainless steel to dramatically reduce the city's water loss. In Detroit, Michigan, in the U.S., dumped wartime steel sheds are being brought back to life. These are being converted into places of accommodation which look attractive and provide low cost living in an artful manner.

Smart cities will house cohesive societies with intensive steel use. They will include advanced architecture and city planning and buildings made with eco-friendly yet sturdy and durable materials. They will have advanced technology for faster communication and transportation and adequate water resources. All the above aspects will be energy efficient as well.

 

2. ADVANTAGES OF STEEL CONSTRUCTION

1. All sewage, drainage, water, casing for cable for Internet or transmission, will ensure zero wastage and maintenance.

2. If roads are laid with concrete strengthened with steel, it translates to lesser damage over a period.

3. Drinking water pipes made of stainless steel for transporting water after filtration are not only good for health but also stop leakage of potable (clean and drinkable) water, a precious commodity today.

4. Bridges, culverts and crash barriers of steel will protect valuable lives.

5. No debris and faster execution of projects.

6. Assets created promise to be long lasting.

7. Steel is also 100% recyclable, and thus, environment friendly.

8. In the long run, it will reduce life cycle costs.

Principle of life cycle cost

There is a misconception that steel works out to be expensive. In many government projects relating to roads, bridges, buildings, construction of railways and shipping, the principle of life cycle cost will play a decisive role in the sanctioning of the project design.

The use of steel has a major bearing on the life of the project. In the long run, it will reduce life cycle costs. There might be several projects that are steel intensive and may incur higher initial costs. But, in the long run, their overall cost comes down which is determined by factors such as material, quality, repairs needed, the time for execution of the projects, etc. All such projects will add to the inventory of national assets.

 

3. DISADVANTAGES OF STEEL CONSTRUCTION

In spite of many advantages, there are few drawbacks with steel construction:

1. Steel corrodes in very humid areas, coastal regions and moist areas of building like bathrooms. Builders have to use coatings of anti-corrosive agents to protect the structure.

2. Steel is a good conductor of heat and cold. Hence, it is not ideal where insulation is required. Additional insulation is required to make a steel building energy efficient.

 

4. STEEL FABRICATION AND WELDING

The success of building construction using steel fabrication is highly dependent upon successful welding techniques. Refinements in welding techniques have allowed architectural designs to be more complex and stylized than ever before. Not only is welded steel safer, it is also cost effective.

Besides civil engineering, steel fabrication and welding finds a lot of applications in mechanical engineering, automobile engineering, aerospace engineering, marine engineering etc. The principles of welding as a metal joining process are dealt with in Chapter 2(A).