www.www.bussiapp.com

[JVCSNL]

Dear All,

I understand that in India, we still have RCC as preferred material for building construction. My perception is that use of structural steel in tall structures is not much in India. Can anyone highlight the statistics of Steel buildings and concrete buildings?

Having little experience of working with overseas projects, I have seen extensive use of structural steel in most of the high rise buildings. Also, in order to deal with loads and other services requirement, use of alternative materials or methods is quite extensive.

I understand that most of the overseas residential buidlings use hollow concrete planks for floor. The openings in concrete slab not only reduces the dead loads but also provides space for routing other building services like cables, water and drainage pipes. Reduced dead load will also reduce the seismic weight.

I have few questions/observations for follwoing two points:

A. Use of Steel in Building industry.

1. Steel has much capacity compared to concrete. I understand that steel construction in general is perceived to be expensive. But this is not always true. For large loads, stel is always a preferred choice of engineer. Is Steel construction very expensive compared to RCC even for all high rise buildings?

2. Steel construction of high rise building require sections having large sectional area by large flange and web thicknesses. Does our steel producers make such sections?

3. Reduced plan dimensions of sections will give lot of room for floor area and may also be suitable for aesthetic purposes dur to slim sections.

4. Steel construction will require adequate measures for fire safety. Do we have adequate resources in terms of material and contractors who can do it?

5. Steel construction is faster compared to RCC. The sections may be brought directly from shop and very less field work will be required. Do builders give due consideation to time value in their commercial analysis of project?

6. Bolted connections can make building erection much faster. We are yet to adopt this philosophy. Experts can highlight pros and cons of bolted construction use as of today in India.

7. Many options are available in steel for lateral load resisting system. Adequate floor and vertical bracing system can provide lot of stability to the structure under lateral loads.

B. Alternative materials

1. Why such hollow precast planks not popular in India? Can the same be used with RCC construction also?

2. Light weight partitions are not much seen in India. Is it that the consumer is scared to adopt new material or is it not suitable to our environment.

Let me inform that I have not much exposure to taller residential buildings. However, having worked for tall plant buildings, both concrete and steel, in the range of 40 to 60m, I believe that steel construction is far more suited in overall terms.

Is it that our infrastructure or builder & consumer mindset or lack of availability of suitable materials limits the building construction to only RCC as an option?

I think, we need to challenge our assumption that steel is very expensive, always. If we need to fast respond to needs of our nation, we should address it appropriately. Looking forward to get educated through experts of tall buildings.

Regards,

Jignesh V Chokshi

[suraj]

Structural Steel & Alternative materials

1. In fact, there is no bar on use of structural steel inclusion on buildings
   
2. Structural steel buildings can be produced very well even, in ours
   
3. Industrial projects are generally, constructed by structural steel framing or trusses, when large span sheds are required
   
4. Residential buildigs can also, be produced using structural steel, but provision of fire resistance should be included, which would require concrete encasing around steel solumns & beams
   
5. Applications of fire resistance coating does not give an attractive decorative residential look
   
6. For industrial projects, coating can successfully be applied
   
7. Moreover, residential buildings require & define specific architecture, that is easily delivered involving RCC materials
   
8. RCC can be site produced meeting all requirements
   
9. Indeed, structural steel can be delivered ready made, but factory specific only
   
10. Structural steel design would depend on standard sections of RS available, which confines options demanded by owner
    
11. Structural steel of course, weighs lesser per square meter & cost of construction too is much lesser than conventional RCC
    
12. From 30 kg to 50/70 Kg/ sqm of structural steel use can produce varying use of buildings, but decoration would require enormous cost
    
13. Precast hollow RCC panels have been in use in many countries around, to be included for fast track construction with better quality controls
    
14. Such methods can be used only, where there is adequate access to site locations
    
15. It also, requires lifting equipment of demanded capacity
    
16. In ours, it has been regretfully noticed that even, no acces is allowed for reinforcing bars to be delivered in straight length of standard sizes
    
17. Reinforcing bars are commonly bent & delivered by ordinary trucks, since, most areas do not allow trailer entries
    
18. Precast panels require production within factory equipped with all requirements, which possibilty is yet remote to my information, but may start in future
    
19. Moreover, on top of all explanations, ours public do not have any interest in quality requirements in reality, but limited on documents only
    
20. Engineers are not well required on technologies implementations
    
21. Promoters are in general, interested on making profits only, without even, caring for basic effects
    
22. No intention to criticise any more for ours, but facts remain to be resolved
    
23. There is no use to compare our current status with other nations that respect regulations & engineering
    
24. Ours did not even care for Engineer regulated mandatory status
    
25. 我们的工程师没有特定的责任or legal responsibilities, but just to do jobs & earn monthly salaries & report to architects
    
26. Use of light partitions has been made in gulf countries for many years, but to my observation, these have not been satisfactorily successful
    
27. Cement boards, gypsum boards & magnesium oxide boards have been in use
    
28. MGO have been introduced recently, but effect is yet to be announced
    
29. Cement & gypsum boards can be successful only depending on weather conditions suitabilty, otherwise, warping can result
    
30. I experienced on one project that gypsum boards within interior of buidlings were included, but building could not be closed for years, which situation deteriorated all boards to an extent that ceramic tiles on walls attained out of line & in many cases were removed to redo
    
31. Light boards can survive satisfactorily, only when a strong & durable metallic backing is provided, which is not done to an extent demanded by technology, but required with continuous non exposure to weather conditions

[R L DINESH]

Dear SEFi's ,
Choice of RCC & Steel depends on factors like construction cost, less weight of construction, stiffness, flexibility of plan, behavior in fire, construction time and usable area. A general guide lines collected from tall structures references is enclosed.
+ sign indicate suited. ++ sign indicate more suited

CRITERIA	RCC Normal	RCC High Strength	STEEL	COMPOSITE
Construction Cost	+	++	0	++
Less Weight of construction	0	+	++	+
Stiffness	++	++	0	+
Flexibility of plan	0	0	++	+
Behavior in Fire	++	++	_	+
Construction time	+	+	++	++
Usable area	_	+	++	+

Regards

[francis chacko]

Will the steel structure be economical when compared to RCC tall structure?

On Tue, Nov 20, 2012 at 9:40 PM, suraj forum@www.bussiapp.com)> wrote:

[JVCSNL]

Dear All,

The issue is not only cost of tall steel structure as of now.

针对使用钢布鲁里溃疡ilding industry, the costs will not be competitive. Probably, we also don't have many fabricators and erectors for tall structures. Also, the heavy sections required are not rolled and hence, builtup sections are the only choice, which makes the costs high.

I wanted to know our nation's readiness to adopt steel as material for high rise buildings. I know there is sincere effort in this line but yet a long way to go.

I assume that if these issues are addressed the costs will definitely come down in coming years.

Do we have comparative analysis on this issue? Else, we have no choice but continue.

Regards,

Jignesh V Chokshi

[bharatthej]

cannot agree more.further more the combination of hot rolled and metal stud framing is quite pivitol considering the ease of fabrication and dead weight(of light gauge framing). the elements contributing to stiffness of building can be hotrolled and the diaphragm/drywalls can be metal stud framing.


On Thursday, November 22, 2012, JVCSNL forum@www.bussiapp.com)> wrote:
[quote]Dear All,

The issue is not only cost of tall steel structure as of now.

针对使用钢布鲁里溃疡ilding industry, the costs will not be competitive. Probably, we also don't have many fabricators and erectors for tall structures. Also, the heavy sections required are not rolled and hence, builtup sections are the only choice, which makes the costs high.

I wanted to know our nation's readiness to adopt steel as material for high rise buildings. I know there is sincere effort in this line but yet a long way to go.

I assume that if these issues are addressed the costs will definitely come down in coming years.

Do we have comparative analysis on this issue? Else, we have no choice but continue.

Regards,

Jignesh V Chokshi



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Posted via Email

[kapildingare]

Dear Sefians,

Posting here article on relative comparison on 30 storey building with R.C.C ,Steel and composite as framing options,I think it will be useful,Seniors please comment.

Thank you.



KAPIL DINGARE