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bishwa SEFI Regulars
Joined: 26 Jan 2003 Posts: 22
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Posted: Fri Mar 09, 2012 10:45 am Post subject: Need for performance specifications for Durability |
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On 07-03-2012 11:03, manu_santhanam wrote: 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.
| Dear All,
I have been also following the ECONF, the issues raised by Dr. Manu are very much relevant. To my understanding there is no reliable way to estimate the service life of a structure yet to be constructed, how does one specify then 100years of complete maintenance free design life? Some of these issues actually I had addressed in my article in ICJ which was posted in this CONF one may look in to the same. The issue of quality in construction is very relevant in India as possibly 50 % or more of our cement is used in non/semi engineered concrete. The buildings are the main culprits.
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lkjain.ngp SEFI Regulars
Joined: 14 Aug 2010 Posts: 37
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Posted: Fri Mar 09, 2012 3:20 pm Post subject: Need for performance specifications for Durability |
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Dear sirs,
With reference to series of discussions drifting to new issues, sadly I like to express as below. Er. VR Kulkarni asked me to comment on some issues, and I did sent him, but those are still out side the conference.
BIS committees:
I see that in last 20 years top brains from research and academics are keeping away from the committees. Similar is the story of top consultants. As per classification of membership, consumers as % of membership is very low. I see that, it very easy to joint any BIS committee, for one who can keep himself up to date and contribute. Time wise we may find other work more important or remunerative, hence we keep ourselves away from such committees.
Whether BIS or ICI, it is the collective responsibility of those who express them selves to be the leaders of the profession, to come to meetings and contribute positively at least by sending comments.
Any important standard, and find that there are not even a dozen comments.
Cement :
Strength of Indian 53 grade cement is far below the cement used world wide. We can not export just 53 grade to Europe, as it is much below their strength standards.
Cement 33 grade is not available because there is no buyer. All those in construction industry, generating cement demand (owners, contractors, supervisors, architects, govt engineers and practising engineers) wants a higher strength cement (even for masonry work), and their perception is that "higher the strength more durable is the structure". Some of us discuss otherwise in a conference, are not even any significant fraction (<0.1%) of the consumers.
Cement industry is driven by market forces. We failed to understand this simple fact, and assume it be "cartel", and can not drive to any solution.
Few of us, if we can analyse and understand, should work collectively, give time, and serve our profession.
It is also a fact that, cement manufacturers are holding a upper limit on cement strength for a grade. They are also holding grade business in blended cement. Blended cements has a major (say 60%) market share in India. Though blended cements standards have only 33 grades, and yet not introduced 43 and 53 grades, but in market blended cement is being sold which has as strength above 43 & 53. The fact is, no one wants 33 grade cement.
If 53 grade cement is perceived to for high strength concrete, than we should newer introduce 63 & 73 grade cement to be at par with Europe or the DEVELOPED WORD.
I request that, lack of understanding should not rule in the concluding discussion of the conference, and drift the majority of professionals away from reality.
L. K. JAIN
On 7 March 2012 11:03, manu_santhanam <forum@sefindia.org (forum@sefindia.org)> wrote:
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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bsec Bronze Sponsor
Joined: 26 Jan 2003 Posts: 204
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Posted: Sat Mar 10, 2012 5:15 am Post subject: Need for performance specifications for Durability |
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Dear Members,
The issue of service life design raised by Dr Manu & Prof. B B Bhattacharjee of IIT Delhi are very relevant in today’s concept. In this regard, I wish to mention that a seminar was conducted in November 2011 by ICI-Delhi Chapter wherein 2 eminent international speakers (Stuart Mathews of UK & Steiner Helland) gave an overview of the concept of service life design of structures and state of the art.
Considerable amount of work is going on internationally in prediction of service life of structures. There is an ISO document (ISO/DIS 16204) and an fib bulletin (Bulletin 53), which covers this aspect in great detail. The presentation material for this seminar will be available with ICI and anyone interested to get the same may contact ICI-Delhi Chapter.
We have to travel a long distance to catch up with the international practice in this regard. Till such time, the design life is just a concept, which we can presume to happen, if the design & detailing is carried out by competent engineers, as per the codes and construction follow the norms and good engineering practices, the concrete is cured well and also routine maintenance is carried out during the design life pro-actively.
With best wishes
Alok Bhowmick
On Fri, Mar 9, 2012 at 11:55 PM, bishwa <forum@sefindia.org (forum@sefindia.org)> wrote:
[quote] On 07-03-2012 11:03, manu_santhanam wrote: --
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bishwa SEFI Regulars
Joined: 26 Jan 2003 Posts: 22
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Posted: Sat Mar 10, 2012 3:13 pm Post subject: Need for performance specifications for Durability |
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On 10-03-2012 00:03, lkjain.ngp wrote: [quote] Dear sirs,
With reference to series of discussions drifting to new issues, sadly I like to express as below. Er. VR Kulkarni asked me to comment on some issues, and I did sent him, but those are still out side the conference.
BIS committees:
I see that in last 20 years top brains from research and academics are keeping away from the committees. Similar is the story of top consultants. As per classification of membership, consumers as % of membership is very low. I see that, it very easy to joint any BIS committee, for one who can keep himself up to date and contribute. Time wise we may find other work more important or remunerative, hence we keep ourselves away from such committees.
Whether BIS or ICI, it is the collective responsibility of those who express them selves to be the leaders of the profession, to come to meetings and contribute positively at least by sending comments.
Any important standard, and find that there are not even a dozen comments.
Cement :
Strength of Indian 53 grade cement is far below the cement used world wide. We can not export just 53 grade to Europe, as it is much below their strength standards.
Cement 33 grade is not available because there is no buyer. All those in construction industry, generating cement demand (owners, contractors, supervisors, architects, govt engineers and practising engineers) wants a higher strength cement (even for masonry work), and their perception is that "higher the strength more durable is the structure". Some of us discuss otherwise in a conference, are not even any significant fraction (<0.1%) of the consumers.
Cement industry is driven by market forces. We failed to understand this simple fact, and assume it be "cartel", and can not drive to any solution.
Few of us, if we can analyse and understand, should work collectively, give time, and serve our profession.
It is also a fact that, cement manufacturers are holding a upper limit on cement strength for a grade. They are also holding grade business in blended cement. Blended cements has a major (say 60%) market share in India. Though blended cements standards have only 33 grades, and yet not introduced 43 and 53 grades, but in market blended cement is being sold which has as strength above 43 & 53. The fact is, no one wants 33 grade cement.
If 53 grade cement is perceived to for high strength concrete, than we should newer introduce 63 & 73 grade cement to be at par with Europe or the DEVELOPED WORD.
I request that, lack of understanding should not rule in the concluding discussion of the conference, and drift the majority of professionals away from reality.
L. K. JAIN
On 7 March 2012 11:03, manu_santhanam forum@sefindia.org (forum@sefindia.org))> wrote:
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bishwa SEFI Regulars
Joined: 26 Jan 2003 Posts: 22
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Posted: Sat Mar 10, 2012 3:13 pm Post subject: Need for performance specifications for Durability |
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On 10-03-2012 00:03, lkjain.ngp wrote: [quote] Dear sirs,
With reference to series of discussions drifting to new issues, sadly I like to express as below. Er. VR Kulkarni asked me to comment on some issues, and I did sent him, but those are still out side the conference.
BIS committees:
I see that in last 20 years top brains from research and academics are keeping away from the committees. Similar is the story of top consultants. As per classification of membership, consumers as % of membership is very low. I see that, it very easy to joint any BIS committee, for one who can keep himself up to date and contribute. Time wise we may find other work more important or remunerative, hence we keep ourselves away from such committees.
Whether BIS or ICI, it is the collective responsibility of those who express them selves to be the leaders of the profession, to come to meetings and contribute positively at least by sending comments.
Any important standard, and find that there are not even a dozen comments.
Cement :
Strength of Indian 53 grade cement is far below the cement used world wide. We can not export just 53 grade to Europe, as it is much below their strength standards.
Cement 33 grade is not available because there is no buyer. All those in construction industry, generating cement demand (owners, contractors, supervisors, architects, govt engineers and practising engineers) wants a higher strength cement (even for masonry work), and their perception is that "higher the strength more durable is the structure". Some of us discuss otherwise in a conference, are not even any significant fraction (<0.1%) of the consumers.
Cement industry is driven by market forces. We failed to understand this simple fact, and assume it be "cartel", and can not drive to any solution.
Few of us, if we can analyse and understand, should work collectively, give time, and serve our profession.
It is also a fact that, cement manufacturers are holding a upper limit on cement strength for a grade. They are also holding grade business in blended cement. Blended cements has a major (say 60%) market share in India. Though blended cements standards have only 33 grades, and yet not introduced 43 and 53 grades, but in market blended cement is being sold which has as strength above 43 & 53. The fact is, no one wants 33 grade cement.
If 53 grade cement is perceived to for high strength concrete, than we should newer introduce 63 & 73 grade cement to be at par with Europe or the DEVELOPED WORD.
I request that, lack of understanding should not rule in the concluding discussion of the conference, and drift the majority of professionals away from reality.
L. K. JAIN
On 7 March 2012 11:03, manu_santhanam forum@sefindia.org (forum@sefindia.org))> wrote:
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mkalgal Silver Sponsor
Joined: 26 Jan 2003 Posts: 54
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Posted: Sat Mar 10, 2012 8:06 pm Post subject: |
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Dear LK (Er. L. K.Jain) has put the issues wrt functioning of codal committees in proper perspective. As he has mentioned how many knowledgeable practitioners willingly come forward to participate in the code committees? Very few. We are all too busy to volunteer our services except for few noble souls like LK. Yes, there are issues of expenses towards travel and stay expenses (since BIS does not pay) in addition to spending valuable time. This leads to the participation mainly by nominees of Institutions like NCCBM, CBRI, SERC etc and of course representatives of Cement Companies whose expenses are borne by the respective organisations. Are they to be blamed to have attended? I may be sounding harsh but it is the hard fact that it is fashionable to talk of cartels.
Regarding the observation of dear Alpa about prescriptive specs vs performance based specs brought out by Er. Kulkarni, I also feel that for some more time to come we must stick to prescriptive specs since majority of the constructions are handled by less trained (untrained?) personnel who do not understand the implications of not following good practices nor have the sense of commitment to their profession ingrained in them. But yes, it is good to have the performance oriented specs available for those who are knowledgeable, committed and daring enough to go beyond the prescriptive codes.
regards
Dr. M R Kalgal
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