Progressive collapse of structures

Progressive collapse of structures means disproportion in size. Though the disproportion between cause and effect is a common feature, there are various differing mechanisms that produce such an outcome. The readiness to the theoretical treatment, approaches for quantifying indices, and possible or preferable alternate measures can vary accordingly. It is better to distinguish and describe the different types of progressive collapse. The term propagating action refers to the action that results from the failure of one element and leads to the failure of further similar elements.

A progressive collapse can be triggered by accident actions, including fire hazard, gas explosion, terrorist attack, vehicle collision, design and construction errors, and environmental corrosion. Due to industrialization, the buildings with multi-function and high complication become more common of which the safety and stability are far more concerned. Thus during the long-term use, the structure may suffer unexpected accidental actions, causing local damage or failure.

The progressive collapse of building structures is a complicated mechanical behaviour of the entire structural systems under large deformation. Problems such as large displacement, large rotation, contact and collision between specimens are inevitable during progressive collapse. Therefore, it is important to select the appropriate model for analysis to consider these features. Targeting at different objects, various progressive collapse models have been developed. The most representative models are the finite element model and the discrete element model. Before the failure of the entire structure the accurate mechanical behaviour can be calculated, but the following condition such as moving and collision between rigid bodies is hardly represented.

The progressive collapse of building structures can be analyzed using three finite models, they are the fine model, simplified model and multi-scale model. According to the mechanical behaviour of structural members the fine model can be established. This method is widely used for specimen because of its large calculations and large modelling process. Since the fine model is more time consuming and laborious simplified model is more preferred in the investigations on the progressive collapse. The ultimate mechanical behaviour of structures can be known by the simplified finite model. The finite element model can calculate the mechanical behaviour before the failure of the entire structure but the collision between the rigid bodies is not represented. The discrete element method brings out the mechanical behaviour of the structure. The dynamic effect can be known by comparing the internal forces and deformations in the dynamic and static analysis. The dynamic equation for structural progressive collapse is very complex hence is very difficult to obtain the simple mathematical expression of the dynamic effect. The structural ability to withstand the local damage due to accident is known as the robustness of the structure design courses in kerala. There are two classifications of the design methods for progressive collapse of building structures (1) the incident-dependent progressive collapse design; (2) incident-independent progressive collapse design. The first one is more accurate and mostly used with buildings with high safety requirement. The second method is all the more simpler.To put an end to the huge damage caused due to the progressive collapse several international designs and codes have been brought into effect.

Design of steel structures

The steel structure course in kerala should have adequate strength, stiffness and toughness for proper functioning.

Design Process

  1. Preliminary member sizing of beams
  2. Structural analysis – modeling, analysis
  3. Design review – member modifications
  4. Cost of estimation
  5. Preparation of structural drawings and specifications
  6. Loads for structural analysis and design
    1. Dead load
    2. Live load
    3. Mean return period OR
    4. Recurrence interval OR
    5. Live loads for various occupencies
    6. Reduction in basic design live load
    7. Impact Load
    8. Wind load

1. Adaptations to site:

If it is a building, the design must be such that there are suitable arrangements for rooms, corridors, stairways, windows, elevators, emergency exits etc and all this plan should be adapted to site so that it is acceptable and at a reasonable cost. This is called functional planning.

2. Structural scheme:

structural scheme is dependent on functional planning. Structural scheme includes the location of columns in the buildings, it is to be carried out with the functional plan and sufficient space must be calculated between finished ceiling and finished floor for location of columns.

3. Structural analysis:

Once the design is laid out, structural analysis must be performed to determine internal forces that will be produced in the framework. Proper calculations must be made and it should be ensured that structure in reality also behaves as it is supposed to be

5. Factor of safety:

The following factors must be considered while developing of design to provide suitable values of the margin of safety and reliability.

  1. Variability of the material with respect to strength and other physical properties
  2. Uncertainty in the expected loads
  3. Precision with which internal forces are calculated
  4. Possibility of corrosion
  5. Extent of damage, loss of life
  6. Operational importance
  7. Quality of workmanship

The design safety of structures may be evaluated in either of the two ways:

  1. Allowable Stress Design
  2. Load and resistance factor design

A. Allowable stress design:

  • Based on the elastic behaviour of the material.
  • The stress is in allowable limits.
  • The full strength of the material is not utilized but we use less value as the limited stress value.
  • It is based on the elastic behaviour of the material
  • The stress on structural members is kept within the allowable limits
  • Full strength of the material is not utilized and a lesser value of the limited stress value is used.
  • The compressive stress is divided by a factor of safety to obtain an allowable or working stress.

Disadvantages of Allowable stress design

  1. In ASD the internal stress is zero before any loads are applied .
  2. ASD does not give reasonable measure of strength. As strength is more fundamental measure of resistance than allowable stress. Safety is applied only to stress. Loads are considered to be uniform. To overcome the above limitations and drawbacks LRFD was evolved.
  3. During manufacturing of steel when it is cooled, the rate of cooling at the top is different than at the bottom or middle and so it causes differential cooling, thus, introducing induced stress internally.
  4. It does not give reasonable measure of strength. .
  5. Safety is applied only to stress level. Loads are considered to be uniform. If not, only option is the factor of safety.

B.Load and Resistance Factor Design(LRFD)

This is based on the principle that strength of various materials and the applied loads depend on certain factors, and thus the structural elements are designed using reduced strength and increased loads.The strength is reduced on the basis of the strength of the material. The load factor is more for the materials that cannot be easily predicted.

Structural behaviour of Steel

Steel structures comprise a large portion of the existing infrastructure worldwide. A number of factors can potentially cause major problems in steel structures in general and steel bridges in particular. These include corrosion, fatigue, design errors, sub-standard materials, vehicle-caused accidental damage, and lack of proper maintenance. In other cases, steel bridges may not be deteriorated or damaged but are rather in need of upgrading to carry larger loads and increasing traffic volumes. In most cases, the cost of adding a component is far less than the cost of replacement and it takes less construction time and therefore reduces service interruption time.

Conventional repair methods of steel structures courses in kerala generally involve bolting or welding Also, adding heavy steel plates increases the dead load of the structure, which limits the target increase of live load carrying capacity. The continuous process of corrosion and the reduced fatigue life associated with the welded steel plates may reduce the durability, and limit the effectiveness, of conventional repair methods Despite the higher cost of FRP materials, compared to steel, the material cost alone generally comprises a very small portion of the overall project cost.. They also have a minimum visual impact on aesthetic appearance and almost no effect on clearances underneath the retrofitted girders.

Retrofit of existing structures is typically needed when live loads increase beyond those the structures were originally designed for. It may also be required because of an inadequate design, damage, fatigue cracking, or deterioration such as corrosion. The following steps are recommended for upgrading steel bridges 1. Welding cover plates to the critical flange areas of the bridge floor beams. 2. When flange material is added, the existing bolting system may become insufficient. This should be corrected by adding more bolts or substituting larger bolts. 3. Bearing stiffeners may be reinforced by bolting or welding angles or by welding plates. 4. Intermediate stiffeners may also be added by bolting or welding plates. 5. If the web was not originally spliced to resist moment, it may be spliced by adding side plates. 6. Tension truss members can be reinforced by the addition of adjustable bars or cover plates. Cover plates must, however, be welded to the gusset plates. 7. Compression truss members can also be strengthened by adding cover plates, either to convert un-symmetric cross sections to a symmetric geometry, or to reduce the width-to-thickness ratio of the plates that comprise the cross section, in order to avoid local bucking and fully utilize their yield strength.

The inherent high strength and stiffness of steel makes it a more challenging material to strengthen, compared to other materials such as concrete and wood. If steel is retrofitted using a material with a lower Young’s modulus, load transfer and hence load sharing of the strengthening material will only be significant after the steel yields .Carbon fibers have outstanding mechanical properties that could be superior to those of steel. It can be concluded for these studies that the use of CFRP materials with elastic modulus equivalent to that of steel and a reasonably high tensile strength would be most suitable for increasing flexural strength of steel beams. On the other hand, CFRP with even higher modulus or larger cross sectional area would be required to increase stiffness of steel beams.

Steel Erection

There are four main steps for steel erection

  • Making sure that the foundations are suitable and safe for erection.
  • Cranes are used for lifting and placing components into position.

Alignment of the structure has to be done by checking that column bases are lined and in level.

  • All the connections have to be checked to make sure that the frame is rigid.

Cranes and Mobile Elevating Work Platforms are usually used for the erection of structural steel designing course in kerala work for buildings. Cranes can be of two types mobile and non-mobile. Mobile cranes include truck mounted cranes, crawler cranes and all-terrain cranes whereas non mobile cranes refers to the tower cranes.

MEWPs are used during steel erection which means it is used to bolt-up the pieces being lifted in by the crane. The MEWPs can be used either on the ground or on the partly erected steelwork to erect lighter steel elements directly .Also the steel work must be able to support the weight of the MEWP. Usually truck mounted cranes do not require a back-up crane and require very little set-up time. These two features mean that they are suitable single day commissions. It requires a larger footprint than what is required for an equivalent crawler crane to achieve a high lifting capacity from a light vehicle. The size of the footprint can be increased using outriggers but to provide a solid base and ensure adequate stability, good ground conditions are necessary.

Crawler cranes are stronger than truck mounted cranes therefore Ground conditions are less critical. Crawler cranes can travel with suspended loads on site, because they are stable without the use of outriggers. They do have a high lifting capacity. Since transportation to and from site is expensive, daily hire is not possible. They are more competitive than truck mounted cranes for long periods.

Because of their size, Tower cranes are assembled on site and their operation also requires a second crane. Dismantling, is also very expensive. They are only used when site conditions are in need for an alternative. A tower crane can be possibly affected due to wind loading, which may affect the working of the crane. The advantages of a tower crane is its ability to lift to greater heights and to lift their capacity over a significant proportion of their radius range. A tower crane can be erected within, the building frame. A tower crane can also be tied to the building frame to provide stability as height increases.

The difficulties during steel erection are related to falls from height, either from working positions or while gaining an access to it. Structural instability or any failure during erection handling, transportation and lifting of heavy components could also be a disadvantage. A dedicated department looks after the hazards and risks in steel construction as well as the issues related to works on construction sites

The main objective of the erection process is to handover the frame to following trades in an acceptable condition. The key aspect here is the accurate positioning of the erected frame, and this depends on an understanding of how the erected position of a steel frame is controlled.

A steel structure is an assembly of a large number of relatively slender and flexible components. Overall accuracies of approximately 1 part in 1000 are sought for plumb and line of the completed structure, using components that may individually be manufactured with greater variability. Apart from that deformations of the structure under self-weight of steel may affect its actual position. The concepts involved and the methods used for control of the erected position of a steel frame must be understood clearly.

Fabrication of Steel

The fast growing technology has brought about a big change in the steel Fabrication .Now people prefer readily available fabricated components that can be easily assembled at the site. This ensures a better quality and the work is also completed much faster. At present the fabrication work that is followed in India is based on the old techniques as a result it is inefficient. Thus it is not able to support the growth of steel construction in India. So the structural designers must be aware of the latest methods to be used to bring about a change in the fabrication practices. There are several authorised steel structuring institutes that are authorised to provide coaching regarding the latest steel structuring methods.

The fabrication of steel work for a small project is of assured quality but the same in a large project is poor in quality. The fabrication work at the large construction sites must be equipped with the latest methods and it should not harm the environment. The traditional drilling machines are now being replaced with machine operated tools that are effective in drilling materials that are very thick. Before the components are assembled they are fitted temporarily to check if there are any defects. The reason being when we join manually they may not be aligned properly. Any changes in the alignment can be corrected by heating. When a small area is heated the other areas surrounding the material prevents expansion. Hence, after detecting the minute changes the components are assembled and the alignment is properly taken care of. Proper fastening methods must be used so as to maintain the quality. Designing a structural is costly but it can be effective if it is used in a proper manner.

Steel is a very good material but it is useful only if it is handled by an experienced person who understands the value of it. Fabrication helps in transforming the steel into a product that can be used in large scale construction. Without the proper fabrication steel cannot be used for high pressure applications in big buildings. Welding is the most common method used for fabrication because it is simple to fabricate and it reduces the size of the joint. A welded joint is made by fusing the steel plates along the line of the joint. There are different welding processes used. Metal coating is done to protect the steel from corrosion. The commonly used methods are hot dip galvanising, metal spraying and electroplating. Galvanising is the most common method used for applying metal coating to structural steel designing course in kerala. In this method steel is dipped in molten zinc. Galvanised steel does not require painting. Alternative method of applying metallic coating is metal spraying. The metal in powder form is fed through a special spray gun containing a heat source. Painting is also used to prevent corrosion.

Because of the latest techniques the architectural designs have become more complex and stylish.This is because the quality of the steel used in the designs is good in quality. The use of the latest technology has helped in the formation of three dimensional structures .Fabricated structures can be easily used in any kind of a project but fabrication is a difficult task and has to be done by a professional.

Are there several steel structure component connection?

 

Steel structure : Steel structure is a pre-assembled material (steel) created by the production line into a segment, and after that the site of the site framed by the get together, so the connection between the segments and segments of the formation of steel structure and to guarantee that Structural security is an important part of the work.

Design the basic principles of steel structure designing courses in kerala connection

Sensible outline of the connection, to guarantee that the node has adequate carrying limit and the proper hub solidness, so as to accomplish the transmission of interior power at the hub.

The design should be based on the heap configuration esteem created by the structurer segment internal power reaction to the connection hub computation.

Accurately calculating the internal power that the node gets (or passing) is the essential to guarantee the security of the node. As indicated by the power system of the hub connection, the connection strategy and arrangement the connection are reliant on the heap qualities of the structure or part. The measure of the segment, the span of the association region, the prerequisites of the joint solidness, the development necessities of various connection techniques, the likelihood of construction and numerous different elements.

The basic way of connecting steel

Welding connection (metallurgical type)

So that the metal melts at high temperature after the formation of the whole

Using welding materials: arc welding, gas welding, electroslag welding

Do not use welding material: resistance welding

Fastener connection (mechanical)

Bolts: Common Bolts: Refined Bolts (A, B)

High strength bolts: Coarse bolts (Class C)

Rivets: nail connection: (nail, tapping screws, nails)

Other (chemical formula)

Strong glue: direct bonding parts

Chemical Bolt Bolt: The anchor is integrated with the anchoring foundation by means of structural glue for the connection of steel members to concrete structures.

What are the connection types in a steel structure?

Connections are required to transmit end shear only and to have insignificant imperiousness to rotate. Subsequently don’t trade significant minutes at a complete limit state. This definition underlies the design of multi-story propped traces in the UK formed as ‘clear advancement’, in which the shafts are arranged as just maintained and the fragments are planned for urgent weight and the little minutes influenced by the end reactions from the columns. Quality is given to the propping in order to case or by the strong focus.

Basic connections

Two rule types of basic association are used

Versatile end-plates and

Balance plates.

Normally experienced direct affiliations include:

Bar to-bar and bar to-segment associations using:

Partial significance end plates

Full significance end plates

Parity plates

Area grafts (impacted spread plates or end plates)

Fragment bases

Propping affiliations (Gusset plates).

Fundamental associations can be required for skewed joints, shafts whimsical to fragments and relationship with area networks. These are classed as outstanding affiliations and are managed autonomously.

Difference between Mild Steel & Stainless Steel

Carbon Steel which is known as Mild steel contains carbon as the combination, though stainless steel incorporates chromium.

Stainless steels are combinations that are comprised of iron and for the most part contain around 11.5% chromium.

Carbon steel is a combination that is comprised of the blend of carbon and iron. What’s more, a few different elements with low maximum rates are additionally included, for example, manganese, with 1.65% most extreme, silicon, with 0.60%maximum, and copper, with 0.60% greatest.

Important differences are:

      • Stainless Steel is more impervious to consumption than Carbon Steel.
      • Stainless Steel is less moldable and harder than Carbon steel.
      • Carbon steel is weak than steel.

The Reinforcement Methods for Steel Structures

The main methods of steel structure reinforcement are:

Reduce the load, change the count of designs, and increment the structure of the cross-segment and the association quality, to prevent split engendering

There is a mature involvement, other reinforcement techniques can likewise be used. Distinguishing proof of the need to strengthen the steel structure, as per the extent of harm is, for the most part, partitioned into nearby support and exhaustive reinforcement.

Nearby support is an absence of conveying limit of the bar or connecting joints at the reinforcement, there is an expanded cross-area strategy to diminish the free length of the bar technique and the connection node support method.

Full reinforcement is the support of the general structure, there is no adjustment in the structure of the static calculation of the realistic reinforcement method and change the structure of the static calculation of the two types of graphic reinforcement.

Increase or strengthen the supportive network, yet additionally, a powerful method to reinforce the basic system.

The method for support of the first partial area is the most expensive and most exorbitant strategy (however regularly a practical strategy); the strategy for changing the estimation diagram is best and varied, and the cost is also extraordinarily reduced

1. Before determining the reinforcement plan, the following information should be collected:

The original structure of the completion of the map (including the change map) and acceptance records.

(2) The original steel material report copy or on-site material inspection report.

(3) The original structural components production, installation acceptance records.

(4) The original structural design calculations.

(5) Structural or component damage inspection report.

(6) The actual load and reinforcement after the new load data.

2. The main factors of steel structure damage and reinforcement technical measures

1 Overdue service and structural changes in load

(2) Accidental deformation, distortion, disability, depression, etc., result in weakened cross-section, bar warping, connection cracking.

(3) Temperature difference caused by component or connection deformation, cracking and warping;

(4) Corrosion due to the erosion of chemical substances and electrochemical corrosion caused by weakened steel structure components;

(5) Other including the design, production, construction errors and service during the illegal use and operation. This article origin steel alliance

 Steel structure reinforcement technology measures are mainly three:

(1) Section reinforcement method: in the local or along the full length of steel components to strengthen, even as a whole to make a common force;

(2) to change the calculation diagram: additional support, adjust the load distribution, reduce the internal force level, the statically indeterminate bearing structure forcing displacement, reduce the peak stress;

(3) prestressed cable method: the use of high-strength cable reinforcement structure to enhance the weak links or improve the overall structure of the bearing capacity, stiffness, and stability.

What is the need for a steel crank in slab reinforcement?

In the event that you are asking for to comprehend the wrench in the steel in slab then answer is steel is required for pressure. The pressure in section shifts at various focuses in the chunk. Additionally in section strain is absent on both the appearances in the meantime. Steel is wrenched to take after the strain. This additionally spare the cost as the utilization of the steel is reduced.

Why do you say that pinned supports play an important role in industrial steel structures?

There will never an answer to why.

Overturning calculations for wind and seismic

Equipment installation design

Piping layouts and calculations

Product certification

Seismic code review

Finite element analysis

Structural analysis

Vibration design and analysis

Shock/blast design and analysis

We use that term or word “stuck” to recommend that the steel is flexible. Bits of steel, while associating have been stuck, we have a method for estimating how much influence the building will have when finished.

We pre-made models that have been reused for considerable years have allowed us to quantify all the more correctly what will hold up in this Aquarium, Earth.

Know more about steel structures 

How is steel produced?

Steel is a composite of iron and carbon. So the essential raw materials we require are press mineral and coal. This iron metal along with metallurgical coke delivered from coke oven are fed as raw material into the blast furnace whereby decrease process we make pig iron. These fixings, sintered material (small measured iron metal protuberances and coal) and some fluxes (lime and dololime) are also included. Contrasting option to the blast furnace course is the DRI route. The midrex process, HYL process and so on are the techniques by which wipe iron or DRI can be created. The pig iron delivered from the blast furnace is exchanged to the steel melting shop by a torpedo spoon. After this outer desulphurization might be done relying upon the prerequisite of the client and from there on the pig press is charged into LD converter/BOF. In case of DRI, it is specifically charged into an EAF or CONARC shell and arcing is done alongside external spearing of oxygen. Pig iron contains around 93– 94% Fe, 4– 4.5% C, around 1– 1.5% Si, 1% Mn, S and P under 0.05%. In BOF; oxygen is blown through a water-chilled copper spear to bring off carbon in the scope of 0.02– 0.07% and to evacuate contaminations exhibit in the pig press by shaping SiO2, P2O5, MnO, and FeO. The arrangement of this oxides alongside CO gas advancement happens in various consecutive advances and is subject to temperature and fractional weight kept up in the bath.

Once the essential refining has been done in BOF, the metal is taken to ARS(Argon Rinsing Station), where Al and other Ferro-combinations are added by the steel grade that will be made. An incomplete expansion is being done alongside argon cleansing to execute the shower and to use the high tapping temperature of BOF. In some cases, Al is supplanted by Fe-Si, contingent on whether the grade is aluminum or silicon killed.

Next in the line is the treatment of the warmth in LRF, where secondary refining is carried out by cutting down the sulfur content in the bath. Alloy increments are likewise done to accomplish the last point composition of the grade and the heat is then exchanged to CCM or Continuous throwing machine. If there should arise an occurrence of IF steel(Interstitial free steel); after LRF treatment, the warmth is taken to RH degasser for degassing and decarburization (carbon in these steels are in the scope of 0.002– 0.005%) and afterward at last to the caster.

Which type of steel is used for construction?

In most of the fortified concrete structures or in steel structures two types of steel are utilized. One is mellow steel and another is HYSD (High Yield Strength Deformed Bars ) or otherwise called TOR bars. Gentle steel (Fe 250 )has less quality yet because of the pliability property it is generally utilized as a part of Earthquake opposing structures. HYSD bars of level Fe 415 and Fe 500 are fundamentally utilized as a part of development work. If Pre focused on concrete structures like bridges high-quality steel is utilized.

There are numerous sorts of steel utilized as a part of the development of a building.

Here are the three most basic steel  writes utilized as a part of the development of structures.

1. Mild steel or carbon steel: Carbon steel is considered as exceptionally safe because of its quality and sturdiness. It isn’t inclined to breaking and can persist catastrophes like seismic tremors.

2. Rebar steel: Rebar Structural Steel Detailing Course in TEKLA is used to give solid help to stonework structure. It can give protection and solidness which spreads over a wide zone.

3. Structural Steel: This kind of steel comes in particular shapes like I-Beam, Z shape, L shape, T shape, Rail profile, bar, pole, plate, and so forth. It is solid, bendable and exceedingly solid and can be transformed into any coveted shape.

Is structural steel detailing revolutionizing the construction industry?

 

Yes….!! We can state that steel enumerating is changing the development field.

Few important factors to be considered while developing any building, particularly high rises.

1. Low cost

2. Less construction time

3. Variety of Design

4. And the list can go on.

Particularly the construction of high rises has brought an immense jump into success with the assistance of detailing. Engineers and Architects began to make and explore new design and conceivable outcomes in light of steel detailing courses in kerala. The construction with steel has turned out to be moderate in many developed countries.

Detailing industry isn’t a small occupation and it requires both field and shop involvement or possibly a little knowledge on them two. This is the motivation behind why detailers are prepared well before utilized into constant employments. Detailers take after various models in an detailing work based on the location of the activity. For USA it is AISC(American organization of steel construction).

A great deal of marvels began a long back in steel development.

Is steel structural buildings are more viable than concrete basic structures?

They are both great, yet it depends more on the project at hand, construction laws and the customers necessities what you should use.

Steel structures are lighter, yet they are more costly, also steel conections must be designed and built with more care than their fortified concrete counter parts, be that as it may, it’s simpler to do the math.

Concrete structures are heavier and less expensive, but it depend if it’s thrown nearby or precast.

However, enormous structures have these days mixes like steel bars and sections with concrete slabs or concrete segments with steel shafts and steel decks.

Steel Structure and bridges

Construction of a bridge requires choice of appropriate quality of steel. This relies upon various factors like material properties, design requirements, accessibility of steel, cost of steel, and item details. Basic Steel is broadly utilized for construction purpose. It is used for making construction materials of different shapes and sizes. The structural steel shows different properties like shape, size,, synthetic arrangement, quality etc. They are managed by industry standards.
This 26,500 or more mega ton of high-malleable steel made bridge is remaining over waterway Hooghly since 1943. Actually its a “Steel Truss Cantilever” connect built totally by riveting, without nuts or screws! It stands sixth among world’s longest cantilever spans. An every day activity of around 100,000 vehicles and potentially in excess of 150,000 people on foot, effectively makes it the busiest cantilever connect on the planet.

Examples

Sydney Harbour Bridge (Sydney, Australia): World’s largest steelarch bridge built in 1932
Golden Gate Bridge (San Fransisco, USA)
Weichsel Bridge ( East Prussia)
Ikitsuki Bridge (Nagasaki, Japan)
Akashi Kaikyo Bridge (Kobe, Japan)

What type of steel are bridges made of?
Basically every expansive steel structure in the USA will be made of A36 basic steel, which is a specific steel composite that is indicated by ASTM International.
If a isn’t utilizing A36 steel, it will be a higher-quality composite that has been determined in light of the fact that something should be high-quality, similar to a basic association that has some wacky space limitations. The real evaluations of high-quality steel that are utilized are A992 and A514, albeit some of the time you’ll see others relying upon what’s required.
however, it’s not an extraordinary plan to blend and match different kinds of steel, since it makes constructing the bridge more troublesome. If two sections made of various composites are also measured, at that point there’s a potential for them to get stirred up too, which could cause disastrous disappointment.

Why there is a huge difference in steel buildings in India comparing to Europe, US, UK and Japan

It is estimated that in Europe, UK, US and Japan the percentage of steel buildings is more than 60-70% whereas the percentage of India is less than 1 per cent. Why do you think is this huge gap?

“In India steel has not got its due as it deserves; such a versatile material like steel, has not been as frequently and extensively used by Indian construction industry, until recent times. India, unlike other western countries has a history of British Architecture, which meant major use of stone, concrete, lime and such materials. India is also a labour oriented country, while automation came in much later and at a very high cost. Until a few years ago, steel was being considered to be used only in industrial type of structures; not just was the steel very expensive, but also quality of product and resources available. Way back in 1980s I had used steel to a huge quantity for the development of the revolving restaurant above the existing Ambassador hotel, however it was an expensive affair.

It good to note that, today, the times have changed, India has come closer to the world and it realized that steel can be used in a variety of forms and means to create landmark structures- one can proudly mention today. That steel is being considered for every type of structure and in every form and finish. With good manufactures available and prices being competitive, I am currently designing various forms-Lets just say, as regards to use of steel in construction, India is catching up with other countries!”. PREM NATH, principal, Prem Nath Associates.

“it is common knowledge that the construction cost of steel is much higher that than of concrete. Though factors such as the height and scale of the project influence the cost, working with concrete is roughly 30 to 35 per cent cheaper than with steel. Steel can soften and melt with exposure to extremely high temperatures, and requires an addition of passive fire protection such as spray-on fireproofing

Recent tall structures across the globe such as the Burj khalifa, Shanghai tower, and Taipei 101 are concrete structures. When you compare the skyline of Europe, UK and japan to India, you notice that majority of their high-rises are commercial towers, while in the case of India they are residential towers. They are focused on shorter construction timelines which can be delivered in steel. Furthermore, our metropolitan cities which are home to high-rises are huge clusters, unlike that in other countries where the wind loads need to be considered as they are isolated structures among low laying ones. With the structural stability and integrity of reinforced concrete being same as steel, and the significant relief in cost, the Indian real estate industry finds concrete to be a viable construction material”. REZA KABUL,President,ARK Reza Kabul Architects.

“ A number of factors contribute to this gap in percentage of buildings built in steel detailing course in India. Labour in India is abundant and cheap as compared to the rest of the developed world. Aggregate is not expensive in India which is a big component in RCC construction. Steel buildings; on the other hand, require skilled workmen, which are not easily available in India. Steel prices also fluctuating depending upon various factors. The cost of building in steel is always perceived to be higher as India is a very price sensitive market. The western markets have a huge shortage of cheap labour, and hence economics work differently there. We have to also take into account that concrete is also an insulating material and suitable ti Indian weather conditions where the temperature variance is not as much as US and Europe”. YATIN PATEL, Principal,DSP Design Associates Pvt.Ltd.