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Need for performance specifications for Durability
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vijay.kulkarni
E-Conference Moderator


Joined: 27 Feb 2012
Posts: 6

PostPosted: Tue Mar 06, 2012 5:51 pm    Post subject: Need for performance specifications for Durability Reply with quote

Dear Friends,

The discussion till date has been hovering around certain limited issues in durability such as the role of cement and its changing characteristics, use of SCMs, QA & QC practices, BIS code provisions, special concretes such as HPC, SCC, HVFAC, UHPC, etc.

I think the time has now come to change our direction. There is a need to think afresh, discarding the conventional approach.

Fortunately, such a change is happening  in the sphere of concrete durability. The age-old practice of ensuring durability indirectly by specifying the minimum cement content, maximum free water-binder ratio, grade of concrete, etc. is changing in favor of specifying performance. A perceptible shift is now clearly seen in some advanced countries from the so-called \"prescriptive specifications\" to \"performance specifications\",  which on many occasions is referred as \"P2P\".

The West is now discovering the advantages of P2P. Briefly, these include: clearly defined end result requirements and owner' expectations, concrete mix optimization and field operations conducted to ensure that owner's expectations are met, focus on concrete behavior and characteristics that really matter, encouraging concrete producer to obtain benefits from unique materials and their combinations, technological expertise and knowledge of local materials.  The risks are responsibilities are clearly defined and the penalties and incentives are innovatively incorporated in the specifications. Such an approach is slowly fostering innovations.
In the present Indian context, P2P has a lot of potential. I am therefore requesting readers to peruse through the following documents, which I have found very useful and interesting


  1. ACI  ITG-8R-10, Report on Performance-based Requirements for Concrete, Reported by ACI Innovation Task Group 8, American Concrete Institute, 2010.
  2. Bickley John, Hooton, R D and Hover, K C, Preparation of a Performance-based Specification for Cast-in-Place Concrete, RMC Research Foundation, National Ready Mixed Concrete Association, USA.

For those who do not have an easy access to the above documents, I am pleased to provide three papers presented during the recent Seminar held under the auspices of Indian Concrete Institute (ICI) at New Delhi. The papers may provide some glimpse of recent developments in P2P.

Download it from here:

Why Performance specs_Delhi seminar Author: Vijay Kulkarni
Download Link :  http://www.sefindia.org/forum/download.php?id=6735

Performance specification of concrete with reference to sustainability.
B. Bhattacharjee
Download Link : http://www.sefindia.org/forum/download.php?id=6736


Evolving Performance Specifications for Concrete Construction in India Manu Santhanam*
Download Link : http://www.sefindia.org/forum/download.php?id=6737


At a time when our organized industry is growing fast, some pilot project may be undertaken to understand and possibly demonstrate the befits of P2P in India.


Vijay Kulkarni
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Dr. N. Subramanian
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Joined: 21 Feb 2008
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PostPosted: Tue Mar 06, 2012 7:15 pm    Post subject: Re: Need for performance specifications for Durability Reply with quote

Dear Er Kulkarni,

I have a doubt. You said in one of the postings that a few RMC plants in the country are not providing quality concrete. Er Alpa and another Sefian also informed about it.

If you do not have specific prescriptive requirements, will it not  be difficult to check them? I agree that many developed countries are changing over to performance based specifications, as their quality of execution is high. In countries like India where quality is already suffering and where corruption is at a higher level do you think  P2P will work out? May be it is good for researchers.

P2P Documents for Ready mixed concrete as per NRMCA, USA, can be downloaded from
http://www.nrmca.org/p2p/Guide%20Spec%20Final.pdf
http://www.nrmca.org/p2p/QMS%203%20parts%20small.pdf

Other links to articles on P2P are given below:

http://www.nrmca.org/p2p/P2P%20Lab%20Report%20Jan2006.pdf
http://www.nrmca.org/p2p/Phase%20I%20Report%20Final%20January%202006.pdf
http://www.nrmca.org/p2p/Example%20Specification.pdf
http://nrmca.org/research/Specifying%20Concrete%20for%20Durability%20CIF%20Dec%2005.pdf
http://www.nrmca.org/p2p/ci2809bickley.pdf
http://www.nrmca.org/p2p/P2P%20Article.pdf
http://www.nrmca.org/p2p/Summary%20of%20Performance-based%20Specification%20Research.pdf
http://www.nrmca.org/p2p/AcceptanceCriteria_CIF_Winter_07%20small.pdf

Warm regards,

Subramanian
vijay.kulkarni wrote:
Dear Friends,

The discussion till date has been hovering around certain limited issues in durability such as the role of cement and its changing characteristics, use of SCMs, QA & QC practices, BIS code provisions, special concretes such as HPC, SCC, HVFAC, UHPC, etc.

I think the time has now come to change our direction. There is a need to think afresh, discarding the conventional approach.

Fortunately, such a change is happening  in the sphere of concrete durability. The age-old practice of ensuring durability indirectly by specifying the minimum cement content, maximum free water-binder ratio, grade of concrete, etc. is changing in favor of specifying performance. A perceptible shift is now clearly seen in some advanced countries from the so-called \"prescriptive specifications\" to \"performance specifications\",  which on many occasions is referred as \"P2P\".

The West is now discovering the advantages of P2P. Briefly, these include: clearly defined end result requirements and owner' expectations, concrete mix optimization and field operations conducted to ensure that owner's expectations are met, focus on concrete behavior and characteristics that really matter, encouraging concrete producer to obtain benefits from unique materials and their combinations, technological expertise and knowledge of local materials.  The risks are responsibilities are clearly defined and the penalties and incentives are innovatively incorporated in the specifications. Such an approach is slowly fostering innovations.
In the present Indian context, P2P has a lot of potential. I am therefore requesting readers to peruse through the following documents, which I have found very useful and interesting


  1. ACI  ITG-8R-10, Report on Performance-based Requirements for Concrete, Reported by ACI Innovation Task Group 8, American Concrete Institute, 2010.
  2. Bickley John, Hooton, R D and Hover, K C, Preparation of a Performance-based Specification for Cast-in-Place Concrete, RMC Research Foundation, National Ready Mixed Concrete Association, USA.

For those who do not have an easy access to the above documents, I am pleased to provide three papers presented during the recent Seminar held under the auspices of Indian Concrete Institute (ICI) at New Delhi. The papers may provide some glimpse of recent developments in P2P.

Download it from here:

Why Performance specs_Delhi seminar Author: Vijay Kulkarni
Download Link :  http://www.sefindia.org/forum/download.php?id=6735

Performance specification of concrete with reference to sustainability.
B. Bhattacharjee
Download Link : http://www.sefindia.org/forum/download.php?id=6736


Evolving Performance Specifications for Concrete Construction in India Manu Santhanam*
Download Link : http://www.sefindia.org/forum/download.php?id=6737


At a time when our organized industry is growing fast, some pilot project may be undertaken to understand and possibly demonstrate the befits of P2P in India.


Vijay Kulkarni
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manu_santhanam
SEFI Member
SEFI Member


Joined: 07 Mar 2012
Posts: 1

PostPosted: Wed Mar 07, 2012 5:33 am    Post subject: Performance specifications Reply with quote

Looking at the posts in the E-conference, it is heartening to see that people are indeed concerned about durability. But the bulk of the discussion posted addresses issues that are not directly related.

The know-how for ensuring durability in concrete structures is very much available in India, and most concrete practitioners are aware of the provisions for durable concrete. The reasons for premature failures have been well brought out in previous posts by other members, and I do not wish to further elucidate this issue.

However, I would like to add to the issue of performance specifications raised by Er. Vijay Kulkarni.

Successful implementation of performance specifications requires clear understanding of:
(i) the environmental classification,
(ii) mechanisms of deterioration,
(iii) choice of suitable performance criteria for the specific service environment, and
(iv) limiting values for the parameters that can be specified - these should be linked to the service life.

Some of these issues are brought out in better detail in the links to the papers provided by Vijay Kulkarni (from the Performance Specifications Seminar in Delhi).

The world over, concrete researchers have generated a lot of interest in evolving a scientific approach towards performance specifications. Thus, service life concepts have to find their way into concrete design, especially for environments with carbonation or chlorides. The work of ISO TC 71/SC3 can be looked at for guidance.

Several developments have taken place in India with respect to implementation of durability provisions. Some examples have already been provided b Vijay Kulkarni, with respect to the use of certain durability tests in metro specifications. In the latest IRC code (112:2001), a new set of exposure classifications is introduced, along with limiting values of mix parameters for a 100 year design life. However, there is no indication of what model has been used for the service life. The provisions in IS 456 have not been updated for past 11 years, and are in real need of improvement to reflect the information available worldwide.
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vijay.kulkarni
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Joined: 27 Feb 2012
Posts: 6

PostPosted: Wed Mar 07, 2012 6:06 am    Post subject: SPAM-LOW: Re: Need for performance specifications for Dura Reply with quote

Dear Dr Subramanian,

It is not my contention that India should go whole hog on P2P. I am aware that even in countries like the USA there are only a few examples of P2P. Neither the ACI Committee nor the NRMCA are not looking for a dramatic change in favor of performance-based specifications. However, one things seems to be clear - the future lies in performance specs.
Looking at the experience of advanced countries I feel that time has now come for us to start thinking in the direction of performance specifications and that some pilot-scale projects can be taken up to gain experience.  
Thanks and with regards,
Vijay Kulkarni

From: Dr N. Subramanian [mailto:forum@sefindia.org]
Sent: Wednesday, March 07, 2012 12:46 AM
To: econf@sefindia.org
Subject: SPAM-LOW: [ECONF] Re: Need for performance specifications for Durability



Dear Er Kulkarni,

I have a doubt. You said in one of the postings that a few RMC plants in the country are not providing quality concrete. Er Alpa and another Sefian also informed about it.

If you do not have specific prescriptive requirements, will it not be difficult to check them? I agree that many developed countries are changing over to performance based specifications, as their quality of execution is high. In countries like India where quality is already suffering and where corruption is at a higher level do you think P2P will work out? May be it is good for researchers.

P2P Documents for Ready mixed concrete as per NRMCA, USA, can be downloaded from
http://www.nrmca.org/p2p/Guide%20Spec%20Final.pdf
http://www.nrmca.org/p2p/QMS%203%20parts%20small.pdf

Other links to articles on P2P are given below:

http://www.nrmca.org/p2p/P2P%20Lab%20Report%20Jan2006.pdf
http://www.nrmca.org/p2p/Phase%20I%20Report%20Final%20January%202006.pdf
http://www.nrmca.org/p2p/Example%20Specification.pdf
http://nrmca.org/research/Specifying%20Concrete%20for%20Durability%20CIF%20Dec%2005.pdf
http://www.nrmca.org/p2p/ci2809bickley.pdf
http://www.nrmca.org/p2p/P2P%20Article.pdf
http://www.nrmca.org/p2p/Summary%20of%20Performance-based%20Specification%20Research.pdf
http://www.nrmca.org/p2p/AcceptanceCriteria_CIF_Winter_07%20small.pdf

Warm regards,

Subramanian    
vijay.kulkarni wrote:    
Dear Friends,

The discussion till date has been hovering around certain limited issues in durability such as the role of cement and its changing characteristics, use of SCMs, QA & QC practices, BIS code provisions, special concretes such as HPC, SCC, HVFAC, UHPC, etc.

I think the time has now come to change our direction. There is a need to think afresh, discarding the conventional approach.

Fortunately, such a change is happening in the sphere of concrete durability. The age-old practice of ensuring durability indirectly by specifying the minimum cement content, maximum free water-binder ratio, grade of concrete, etc. is changing in favor of specifying performance. A perceptible shift is now clearly seen in some advanced countries from the so-called "prescriptive specifications" to "performance specifications", which on many occasions is referred as "P2P".

The West is now discovering the advantages of P2P. Briefly, these include: clearly defined end result requirements and owner' expectations, concrete mix optimization and field operations conducted to ensure that owner's expectations are met, focus on concrete behavior and characteristics that really matter, encouraging concrete producer to obtain benefits from unique materials and their combinations, technological expertise and knowledge of local materials. The risks are responsibilities are clearly defined and the penalties and incentives are innovatively incorporated in the specifications. Such an approach is slowly fostering innovations.
In the present Indian context, P2P has a lot of potential. I am therefore requesting readers to peruse through the following documents, which I have found very useful and interesting

<![if !supportLists]>1. <![endif]>ACI ITG-8R-10, Report on Performance-based Requirements for Concrete, Reported by ACI Innovation Task Group 8, American Concrete Institute, 2010.
<![if !supportLists]>2. <![endif]>Bickley John, Hooton, R D and Hover, K C, Preparation of a Performance-based Specification for Cast-in-Place Concrete, RMC Research Foundation, National Ready Mixed Concrete Association, USA.

For those who do not have an easy access to the above documents, I am pleased to provide three papers presented during the recent Seminar held under the auspices of Indian Concrete Institute (ICI) at New Delhi. The papers may provide some glimpse of recent developments in P2P.

Download it from here:

Why Performance specs_Delhi seminar Author: Vijay Kulkarni
Download Link : http://www.sefindia.org/forum/download.php?id=6735

Performance specification of concrete with reference to sustainability.
B. Bhattacharjee
Download Link : http://www.sefindia.org/forum/download.php?id=6736


Evolving Performance Specifications for Concrete Construction in India Manu Santhanam*
Download Link : http://www.sefindia.org/forum/download.php?id=6737


At a time when our organized industry is growing fast, some pilot project may be undertaken to understand and possibly demonstrate the befits of P2P in India.


Vijay Kulkarni

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Dr. N. Subramanian
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Joined: 21 Feb 2008
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PostPosted: Wed Mar 07, 2012 6:15 am    Post subject: Re: Performance specifications Reply with quote

Dear All,

I thank Dr Manu Santhanam, for his posting-also thank Er Kulkarni for asking him to participate in the discussions. Prof. Santhanam, now working in IITM received the Best Concrete Technologist Award from ICI Tamilnadu centre for the year 2011.

As all of us are aware concrete is formed due to the exothermic chemical reactions, producing heat. When we add chemical and other admixtures to concrete, these components should not produce adverse reactions. Such compatibility issues with respect to superplasticisers has been researched well by Prof. Santhanam and presented in a recent paper authored by him with another notable concrete technologist Prof. Ravindra Gettu. I suggest all to read that paper published in the July 2011 issue of ICJ.

Best wishes
Subramanian



manu_santhanam wrote:
Looking at the posts in the E-conference, it is heartening to see that people are indeed concerned about durability. But the bulk of the discussion posted addresses issues that are not directly related.

The know-how for ensuring durability in concrete structures is very much available in India, and most concrete practitioners are aware of the provisions for durable concrete. The reasons for premature failures have been well brought out in previous posts by other members, and I do not wish to further elucidate this issue.

However, I would like to add to the issue of performance specifications raised by Er. Vijay Kulkarni.

Successful implementation of performance specifications requires clear understanding of:
(i) the environmental classification,
(ii) mechanisms of deterioration,
(iii) choice of suitable performance criteria for the specific service environment, and
(iv) limiting values for the parameters that can be specified - these should be linked to the service life.

Some of these issues are brought out in better detail in the links to the papers provided by Vijay Kulkarni (from the Performance Specifications Seminar in Delhi).

The world over, concrete researchers have generated a lot of interest in evolving a scientific approach towards performance specifications. Thus, service life concepts have to find their way into concrete design, especially for environments with carbonation or chlorides. The work of ISO TC 71/SC3 can be looked at for guidance.

Several developments have taken place in India with respect to implementation of durability provisions. Some examples have already been provided b Vijay Kulkarni, with respect to the use of certain durability tests in metro specifications. In the latest IRC code (112:2001), a new set of exposure classifications is introduced, along with limiting values of mix parameters for a 100 year design life. However, there is no indication of what model has been used for the service life. The provisions in IS 456 have not been updated for past 11 years, and are in real need of improvement to reflect the information available worldwide.
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alpa_sheth
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PostPosted: Wed Mar 07, 2012 8:48 am    Post subject: Need for performance specifications for Durability Reply with quote

Thanks Mr. Vijay Kulkarni for adding a new topic to the econf. 


I agree with Dr Subramanian (who as usual posted another insightful mail). This topic of moving from prescriptive to performance based finds itself also being actively debated in structural design. More and more countries are giving an option to go for performance based design. 


Usually one goes for performance based design when the situation (project) is beyond that normally envisaged by the building codes. It could be an iconic building or a very high precision project where the performance standards of the project if designed by the standard codes may fall short of the requirements of the project. We must remember that building codes stress on safety and do not focus too much on finer points of serviceability. 


My point is, one goes for performance based design when one wants to go beyond prescriptive codes- one has higher, not lower, standards than the building codes. It is not a way to circumvent the code but to enhance the code requirements. 


We have been debating much on this esp for earthquake engineering design and I think India has still some ways to go before it is quite there. 


To bring that analogy to concrete technology, when ACI committees  discuss performance specifications,  I assume  they are expecting more enhanced performance  than that given by prescriptive specifications. Unfortunately in India we are not able to even achieve the prescriptive requirements. 


But I do agree with Mr Kulkarni that we need to have the option available to that one-off project which wants to go beyond codes to have performance based specifications and we must have a special code to that effect. It not an either/or situation. It is an "and" situation. Let's have a performance based specification at one end and prescriptive specifications at the other of the spectrum.


I am now going to address a very touchy subject which I had brought up even earlier on SEFI - years ago. In India, the concrete (incl cement) code committees are controlled by the cement industry. Code clauses are often governed by what is expedient to that lobby, not what is good for construction quality.  


I think there is a need to effect sweeping changes. Sure, we need the cement companies represented, but we also need on our concrete code committee independent concrete technologists, designers, academia, serious researchers - there was not a single IIT in CED 2  (IS 456) code committee. And I know some stellar research professors at some IITs.  We need people who  invest their time in research and are up-to-date with State of art, and  international best practices. We need people who are ready to call the bluff of vested interests. 


Everybody is aware of these problems. I remember not a very long time ago one of the IITs decided to overhaul the system and address issues of concrete and essentiall rewrite concrete codes. I was the one who poured cold water on this very laudable endeavour simply because I was realistic (and cynical) enough to know that the cement industry  and other interested lobbies would block any such effort to realise this project  into code changes. 


I do not think it is an impossible situation. It needs dedication from our end and I think we could do it. 


best regards,
Alpa 

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Dr. N. Subramanian
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PostPosted: Wed Mar 07, 2012 3:54 pm    Post subject: Re: Need for performance specifications for Durability Reply with quote

Dear Er Alpa,

Thanks for your kind words.

I think the year 2000 version of IS 456 was also revised mainly by Cement Industry people at NCCBM (of course BIS circulates to other people and get their comments also but to accept any suggestion is left to the people or committee which is drafting the revision)- they left most of the design provisions untouched and added the most wanted durability provisions. I find the only professor on this  committee is Prof. A K Jain of Univ. of Roorkee.

Cement industry is acting on its own to provide the products for use by the general public. Though some of the new products are good some are not necessary. For example they removed Grade 33 cement from the Market-which is very good for majority of the construction projects, which is using M20. Most of the problems which we are taking about now, are due to cracking of concrete are because of  the use of Grade 53 cement which has high early strength and has to be cured as soon as the initial set takes place-Many at site start curing after several hours of placing concrete- this results in cracking of concrete and  gives raise to durability problems. In my opinion Grade 53 cement is required only for HSC.  It is better to print on Cement bags when curing should should start, the % and quality of flyash used etc. like the warnings that are printed in Cigarette packets now-a-days.

In ICI for a long time there was a talk about publishing a code similar to ACI. I think the problem is dedication is lacking. in ACI several persons from different spheres take part actively without any personal gain.

I think it is a bad idea to have Professors or Researchers drafting the code. They will make the code more theoretical with complicated equations and make it difficult to follow. As the codes are mainly implemented by practicing Engineers they should only lead the team perhaps with the assistance of professors.

Regards
NS


alpa_sheth wrote:
Thanks Mr. Vijay Kulkarni for adding a new topic to the econf.


I agree with Dr Subramanian (who as usual posted another insightful mail). This topic of moving from prescriptive to performance based finds itself also being actively debated in structural design. More and more countries are giving an option to go for performance based design.
...........

I am now going to address a very touchy subject which I had brought up even earlier on SEFI - years ago. In India, the concrete (incl cement) code committees are controlled by the cement industry. Code clauses are often governed by what is expedient to that lobby, not what is good for construction quality.  


I think there is a need to effect sweeping changes. Sure, we need the cement companies represented, but we also need on our concrete code committee independent concrete technologists, designers, academia, serious researchers - there was not a single IIT in CED 2  (IS 456) code committee. And I know some stellar research professors at some IITs.  We need people who  invest their time in research and are up-to-date with State of art, and  international best practices. We need people who are ready to call the bluff of vested interests.


Everybody is aware of these problems. I remember not a very long time ago one of the IITs decided to overhaul the system and address issues of concrete and essentiall rewrite concrete codes. I was the one who poured cold water on this very laudable endeavour simply because I was realistic (and cynical) enough to know that the cement industry  and other interested lobbies would block any such effort to realise this project  into code changes.


I do not think it is an impossible situation. It needs dedication from our end and I think we could do it.


best regards,
Alpa

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PostPosted: Thu Mar 08, 2012 4:20 am    Post subject: Reply with quote

Dear Dr. Subramanian,


This is a very good point you made about the termination of Grade 33 cement. In my view Grade 53 should be used only for HSC. The market wants to just jump to any new product that is released. They just think that Grade 53 is higher than Grade 43 so it should be the best. Tomorrow if there is something higher they will stop Grade 43. I will go further to say that there is a cartel of cement vendors in the market. They all join hands and fix the price of cement. Strangely any customer is not allowed to import cement from abroad for their project without the permission of the government of India. Here the political class and the cement vendors work hand in hand.

Non availability of Grade 33 has been the bane of our problems. We are Industrial consultants and we design large slabs on grade for Industrial buildings. Here the effect of shrinkage on concrete is felt to a large extent.

Hopefully things will change. As a nation I think we need a dictator who is not a crook. We are too democratic as a nation.


Regards
Sriprakash
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PostPosted: Thu Mar 08, 2012 7:37 am    Post subject: Need for performance specifications for Durability Reply with quote

Dear Dr. Subramanian,

This is a very good point you made about the termination of Grade 33 cement. In my view Grade 53 should be used only for HSC. The market wants to just jump to any new product that is released. They just think that Grade 53 is higher than Grade 43 so it should be the best. Tomorrow if there is something higher they will stop Grade 43. I will go further to say that there is a cartel of cement vendors in the market. They all join hands and fix the price of cement. Strangely any customer is not allowed to import cement from abroad for their project without the permission of the government of India. Here the political class and the cement vendors work hand in hand.
Non availability of Grade 33 has been the bane of our problems. We are Industrial consultants and we design large slabs on grade for Industrial buildings. Here the effect of shrinkage on concrete is felt to a large extent.
Hopefully things will change. As a nation I think we need a dictator who is not a crook. We are too democratic as a nation.

Regards
Sriprakash



From: Dr N. Subramanian [mailto:forum@sefindia.org]
Sent: Wednesday, March 07, 2012 9:24 PM
To: econf@sefindia.org
Subject: [ECONF] Re: Need for performance specifications for Durability



Dear Er Alpa,

Thanks for your kind words.

I think the year 2000 version of IS 456 was also revised mainly by Cement Industry people at NCCBM (of course BIS circulates to other people and get their comments also but to accept any suggestion is left to the people or committee which is drafting the revision)- they left most of the design provisions untouched and added the most wanted durability provisions. I find the only professor on this committee is Prof. A K Jain of Univ. of Roorkee.

Cement industry is acting on its own to provide the products for use by the general public. Though some of the new products are good some are not necessary. For example they removed Grade 33 cement from the Market-which is very good for majority of the construction projects, which is using M20. Most of the problems which we are taking about now, are due to cracking of concrete are because of the use of Grade 53 cement which has high early strength and has to be cured as soon as the initial set takes place-Many at site start curing after several hours of placing concrete- this results in cracking of concrete and gives raise to durability problems. In my opinion Grade 53 cement is required only for HSC. It is better to print on Cement bags when curing should should start, the % and quality of flyash used etc. like the warnings that are printed in Cigarette packets now-a-days.

In ICI for a long time there was a talk about publishing a code similar to ACI. I think the problem is dedication is lacking. in ACI several persons from different spheres take part actively without any personal gain.

I think it is a bad idea to have Professors or Researchers drafting the code. They will make the code more theoretical with complicated equations and make it difficult to follow. As the codes are mainly implemented by practicing Engineers they should only lead the team perhaps with the assistance of professors.

Regards
NS


alpa_sheth wrote:    
Thanks Mr. Vijay Kulkarni for adding a new topic to the econf.


I agree with Dr Subramanian (who as usual posted another insightful mail). This topic of moving from prescriptive to performance based finds itself also being actively debated in structural design. More and more countries are giving an option to go for performance based design.
...........

I am now going to address a very touchy subject which I had brought up even earlier on SEFI - years ago. In India, the concrete (incl cement) code committees are controlled by the cement industry. Code clauses are often governed by what is expedient to that lobby, not what is good for construction quality.


I think there is a need to effect sweeping changes. Sure, we need the cement companies represented, but we also need on our concrete code committee independent concrete technologists, designers, academia, serious researchers - there was not a single IIT in CED 2 (IS 456) code committee. And I know some stellar research professors at some IITs. We need people who invest their time in research and are up-to-date with State of art, and international best practices. We need people who are ready to call the bluff of vested interests.


Everybody is aware of these problems. I remember not a very long time ago one of the IITs decided to overhaul the system and address issues of concrete and essentiall rewrite concrete codes. I was the one who poured cold water on this very laudable endeavour simply because I was realistic (and cynical) enough to know that the cement industry and other interested lobbies would block any such effort to realise this project into code changes.


I do not think it is an impossible situation. It needs dedication from our end and I think we could do it.


best regards,
Alpa

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Joined: 26 Jan 2003
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PostPosted: Fri Mar 09, 2012 7:45 am    Post subject: Need for performance specifications for Durability Reply with quote

Dear Mr Manu Santhanam,

You may please look at the Presentation material attached in my 28th Feb mail, which addresses the issues that you have raised.

Best Wishes

Alok Bhowmick

From: manu_santhanam [mailto:forum@sefindia.org]
Sent: Wednesday, March 07, 2012 11:03 AM
To: econf@sefindia.org
Subject: [ECONF] Re: Need for performance specifications for Durability



Looking at the posts in the E-conference, it is heartening to see that people are indeed concerned about durability. But the bulk of the discussion posted addresses issues that are not directly related.

The know-how for ensuring durability in concrete structures is very much available in India, and most concrete practitioners are aware of the provisions for durable concrete. The reasons for premature failures have been well brought out in previous posts by other members, and I do not wish to further elucidate this issue.

However, I would like to add to the issue of performance specifications raised by Er. Vijay Kulkarni.

Successful implementation of performance specifications requires clear understanding of:
(i) the environmental classification,
(ii) mechanisms of deterioration,
(iii) choice of suitable performance criteria for the specific service environment, and
(iv) limiting values for the parameters that can be specified - these should be linked to the service life.

Some of these issues are brought out in better detail in the links to the papers provided by Vijay Kulkarni (from the Performance Specifications Seminar in Delhi).

The world over, concrete researchers have generated a lot of interest in evolving a scientific approach towards performance specifications. Thus, service life concepts have to find their way into concrete design, especially for environments with carbonation or chlorides. The work of ISO TC 71/SC3 can be looked at for guidance.

Several developments have taken place in India with respect to implementation of durability provisions. Some examples have already been provided b Vijay Kulkarni, with respect to the use of certain durability tests in metro specifications. In the latest IRC code (112:2001), a new set of exposure classifications is introduced, along with limiting values of mix parameters for a 100 year design life. However, there is no indication of what model has been used for the service life. The provisions in IS 456 have not been updated for past 11 years, and are in real need of improvement to reflect the information available worldwide.

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