There is the glaring need for a structured programme to train and certify...
Which are the grey areas when it comes to ensuring the quality of concrete?
I have seen that in India, our technicians have a knowledge gap in several areas that impedes them from producing and ensuring good quality concrete. One has to have a general understanding about concrete as a material and should be well versed with the mechanism of hydration of cement. We lack awareness about good concrete practices, don´t have sufficient quality assurance or control measures of making good concrete. We must also put more stress on the testing of concrete in a green state and also in a hardened state for the required performance.
How wide is this knowledge gap?
The requirements mentioned above are unfortunately not factored in any contemporary engineering degree / diploma programme or in any site supervisors training imparted today in India.
India is one of the major concrete producing countries in the world today. The Construction industry has assumed a huge financial dimension of Rs. 400,000 crore per year. A substantial part of this expenditure is attributed to concrete. Hence, durability and desired usability for a given service life is a concern we must pay more attention to. Concrete practitioners and site supervisors have to acquire concrete-related experience on site and through self-motivation to excel. There is the glaring need for structured programme to train and certify concrete practitioners in various aspects of concrete and related activities.
How is the American Concrete Institute helping bridge this gap?
American Concrete Institute (ACI), 30 years ago, developed a highly structured programme in the form of ACI Certification Concrete Field Testing. Today more than 5,00,000 concrete practitioners who are certified by ACI, are working all over the world.
How active is ACI in India?
The first batch of trained professionals was certified in Chennai on August 2008. L and amp;T took the initiative and called 23 Senior Managers from all over the country and also from the Middle East to Chennai and a certification programme was conducted. From 2008 to December 2013, these certified professionals have played an excellent role of trainers with an estimated 2,500 personnel working under them who have already benefited in their direct contact with experts, over the past five years.
What is imparted during this training?
Apart from some of the points mentioned above, there are some direct benefits of the ACI Certification. Everyone involved in a construction project benefits from the use of certified technicians to perform the field tests on freshly mixed concrete. Proper performance of the tests improves the reliability of the test results.
How have you been associated with this initiative?
Resources in terms of trained and devoted expert faculty to train the candidates as well as the laboratory facility are the key requirements of the course. I took up the task of training candidates of all the 20 batches trained so far. Chetan Raiker, Chairman and Managing Director of Structwel Designers and Consultants, provided the lab facility, all complimentary.
Tell us about the `Train the trainer` initiative.
One simple but important reason, the course is in English, the manuals and codes too are in English. India is a country where we speak and communicate in a multitude of languages and as you know, English not being our first language, it is difficult to pass on the knowledge. Hence, we decided to train experts in these areas and to train them to train others in the language most comfortable to them.
Could you name a few companies that have benefited from the training?
One outstanding example of training and certification is of a contingent of 150 senior engineers from the Maharashtra Housing and Area Development Authority (MHADA). Along with MHADA and MIDC engineers, other reputed organisations like B. G. Shirke and amp; Co, K Raheja Corp, B. E. Billimoria, Lafarge Ready Mix, RMC, Ultratech RMC, Larsen and amp; Toubro, Sunanda Speciality Coatings, Hiranandani Constructions, Hirco, Godrej Properties, Unity Infraprojects, were all benefited by the course.
We also received participations from consulting firms like Shirish Patel and amp; Associates, Structwel Designers and Consultants, Shashank Mehendale and amp; Associates, SP Consultants, Epicons Consultants, Nina Industries, Bhagubhai College of Polytechnic, etc.
What are the technical factors influence the quality of concrete?
There are seven tests that one needs to perform on green concrete to assess its quality. If these factors are alright, the quality of the concrete is automatically maintained. We stress on monitoring and controlling temperature, sampling, slump density yield, and air content (gravimetric) of concrete, air content (pressure method). air content (volumetric method), Making and curing concrete test specimen in the field.
These seven parameters influence the performance of set concrete and when measured properly as per uniform methodology, can give very important information about the behaviour of hardened concrete. For example, concrete temperature is one of the most important factors influencing quality and time of the set strength of concrete. Without temperature control, , predicting concrete performance is very difficult, if not impossible.
Concrete temperature can give us the following indications about the properties of set concrete:
- Concrete with high initial temperature will probably have higher than normal early strength and lower than normal ultimate strength. The overall quality of the concrete will also probably be lowered.
- Conversely concrete placed and cured at low temperatures will develop strength at a slower rate but ultimately will have higher strength and be of a higher quality.
- Temperature of concrete is used to indicate the type of curing and protection that will be needed, as well as the length of time the curing and protection should be maintained.
Air content is another very important but unfortunately frequently ignored factor.
- Air content measurement of normal and heavy weight concretes and will decide the entrained and entrapped air in concrete.
- Too much entrained air causes problems, eg: concrete designed for 20-35 MPA as the air content increases above 1 per cent air can reduce the strength by 3-5 per cent. All these tests are performed thoroughly by our certified field testers.
So how many concrete field testers are available today?
Today India has more than 400 or so concrete field testing - ACI certified personnel. Another 200 engineers are lined up for training. Together, these 600 trainers will pass this knowledge to say 60,000 field technicians.
But is this number enough to reach the entire country?
No, it is far from sufficient. NSDC has targeted to train only 150 million people out of an incremental demand of 240 million by 2022. This underlines the need of several agencies to cater to the requirement.
What are the challenges faced by ACI?
There are a few challenges on the way ahead. ACI certification is based on ASTM standards. Throughout the country, the Indian Code BIS 456 is followed. ASTM has no acceptance or cross- reference in the Indian Standard. This lack of choice confuses many specifiers / practitioners/consultants/federal departments, etc.