The infrastructure industry in India is growing in a big way. Everyday, new innovations and techniques are brought in to make the construction of structures more efficient. However, one vital spectrum of this industry has been sadly neglected for a long time and not given its due importance, the demolition industry. Highly unorganized and technologically still backward, demolition industry in India still has a long way to go. With all our old infrastructures - dams, bridges, chimneys etc all aging and waiting to be taken down to put up new structures in its place. Many new Thermal, Nuclear & Hydro Power Plants, Underground Metros, Airports, Shopping Malls, giant IT Parks, Factories, Roads, Bridges, Stadiums, Wind farms, commercial and residential buildings are being built all over India today. Not all of them will be considered as monuments for preservations. Very soon these structures will need to be demolished for one reason or the other. And for this, we need to give demolition industry its due importance and recognition.

Mr. Mohan Ramanathan, Managing Director of Advanced Construction Technologies (P) Ltd, has brought about a revolution in this field. He has brought in new technologies of demolition into India and he is the unchallengeable pioneer in the field of demolition. Editor-in-Chief K P Pradeep spoke to him on a variety of issues. The excerpts

What is the scenario of the demolition industry in India?

The demolition industry is unorganized in our country. Its state is not very different from the state of the demolition industry in under developed countries.
Mainly, the construction industry itself has to blamed for this condition, because, demolition is not given its due importance and recognition. As of now,
there is not enough awareness about the various technologies available in this field. We are almost 20 years behind with respect to the technology used for
demolition in developed countries.

So how do you think this situation can be improved?

First of all, creating awareness is very essential. Demolition is a very exciting and challenging area where you have to get things done right the first time. You don't get a second chance to correct your mistakes. Demolition is a specific science and it has to be included as a part of the curriculum in colleges for engineers.Civil engineers must be taught demolition as a course. We need around 500 demolition specialists in the next 10 years. We need to plan and
systemize the teaching of rudiments of demolition to engineering students.

What are the main factors that you consider while bringing in new technology into our country?

First, the technology must be the most economical and cost effective one that is available in that particular field. Second, it must be the fastest and the
safest method. And finally, it must be the most modern method that can be adapted to Indian conditions. Whatever technology that I bring in, I must be able to dissiminate effectively so that others can emulate it and can get benefited.

What are the preparations and the precautions you take you make before demolishing?

First, we carefully go through the structural plan of the building that has to be demolished. In the absence of the plan, a survey of the building is done and we get a line sketch of the building. We need to take a lot more precautions as we have no idea of the design loads and load sharing. Next, we do a careful visual inspection. Depending on the type of demolition technique we are going to use, we either go for non destructive testing (NDT) or destructive testing
Collapse analysis of the building is done through a software simulation, especially for Implosion jobs. This is by a routine producre by CDI, my US collaborator.

We also do a test blast on a single column and learn how it behaves.

Coming to the precaution, I can say that the safety should be given a much higher importance during demolition than during construction. I have my core
team, comprising of well trained personel. They undergo rigorous physical examinations and daily drills to make them more alert and fit. The workers
on the demolition site are provided with proper safety  gears and we also have site supervisors equipped with walkie talkie for easy communication. When we do an implosion, even fire fighters and ambulance are called and kept alert for handling any type of a mishap. The police are also informed and they help in controlling the crowd and traffic.

And what are the major hurdles you face during demolition?

The biggest hurdle is that we don't usually have the structural plans of the buildings that we are going to demolish. This is because we don't have a proper
archiving system here in India. The other hurdle that is unique to India is the problem of bystanders. Nowhere else in the world, you can see people
standing hours together to witness the demolition of the building. In urban demolition, bystanders are a major issue. However, thankfully, we don't get any
bystanders in industrial demolition. Bystanders are potential hazards for me.

Tell us about Implosion.

Implosion is perhaps the safest technique of demolition. This is because we won't have anyone inside the building as everything is remote controlled.
Moreover, it is also the fastest technique. normally takes less than 10 seconds to bring down a building by this technique. However, in India, the use of explosives is a very sensitive subject In case these explosives fall into the wrong hands, the consequences could be terrible. This is the main reason why I offer alternate methods to explosive techniques for demolition.

How do you deal with the pollution that occurs due to demolition?
During a demolition, we have to deal with noise, vibration and dust. Noise: The main sources of noise during demolition are, the noise from the main equipments, activity noise and the support activity noise (like noise due to clearing of debris). However, technological advancement has reached to such a stage that the equipments used for demolition has very low noise levels. It is no more than the sound of a bus going on the road. And with hydraulic crushers replacing the hydraulic breakers, the amount of noise is highly reduced. I brought in the first hydraulic crusher into India in 2006. This greatly reduces noise pollution.Talking about vibrations, the level of vibration is very less with the techniques that we use today.

Dust is a byproduct of demolition. It causes a lot of health problems. Recently, in my demolition of T2A terminal at Mumbai International Airport, I introduced
a new technique to control dust. With the jet aircrafts plying only 50M or so away from the demolition site, dust control was a major factor which had to be taken into consideration, so as to protect the aircraft engines from getting affected by the dust. I brought in the 'Dust Boss' which I used in the Mumbai airport demolition project. This machine is imported from the US. A high pressure jet of water is blown into the sky by a huge fan. The dust particles stick to the molecules of water and they drop down, thus effectively bringing down the pollution due to dust. And the best part is that there is no water in the ground! I recommend the DUSTBOSS to bring down the dust from quarries, crushers, ports.

What was your most challenging job?

All the jobs that I take up are challenging. I mostly deal with new technology with which nobody has prior experience. This makes all my jobs very challenging. But I would say that the Tata Steel project was very special to me. This was back in 1997. We had to dismantle a huge foundation weighing about 700T
in just 48 hours. This meant that my team had to be awake and alert for 48 straight hours, apart from the prior 24 hours during which we had to make preparations. We used the 'Diamond Wire Sawing' technique, which I had introduced into the country for the first time. During the fag end, I personally operated a machine to finish the job. We finished 10 hours late and also lost some money because of penalty clause for delay, but I would say that it was one of the most satisfying jobs that I had done.

The partial demolition of the T2A terminal at Mumbai Airport was also quite challenging. Within 60 days, about 35,000 sq meters of a 4 story terminal
building had to be demolished, that too in a functional airport. For the first time in Asia, high reach demolishers were used. I brought in the first Volvo EC 460UHR machine from the UK. I also used the Dust Boss here for the 1st time in India. We finished the job 11 days ahead. The Mumbai airport project
was a sort of eye opener to the industry, in terms of technology.

What is the scope of deconstruction in India? How far have we progressed in the recycle of debris of demolition?

Let me begin with first defining what Deconstruction is. Removing a structure for building something new is termed as deconstruction. Every material used in construction has energy builtin . While deconstructing, the energy that has gone into the building can be reused. We already  have scrap merchants in India who salvage steel and other valuables from the construction debris and sell it. But they deal only with those materials that have a direct resale value and they do not think about recycling. Because of this, the major part of the debris ends up being used only as landfill material, in an unprocessed form.

But this debris can be recycled back. Just like we recycle garbage, demolition debris can also be recycled. Concrete recycling is currently done in many
countries like Japan, Germany, UK etc. no debris goes out of a site without being processed back to smaller size. They are recycled and even sold back to
ready mix plants where they are used as an input for the manufacture of new concrete.

I even took an initiative recently and demonstrated the concept of the recycling of debris. But when I approached the consultants, they were not willing to use recycled materials into their new project. This highlights the lack of awareness about recycling in our country. Unless and until the Government makes it  andatory to use recycled materials deconstruction and recycling of debris will not become popular in our country.

It is my objective to set up one such model recycling plant in our country. I have approached the Government and if they support me, then I am keen to put this plan into action.

What do you think the government should do support the demolition industry?

City Authorities like BMP, BMC, CMDA, DDA, NDA must specify new modern demolition methods and enlist professional agencies for demolition contracts. They must also allot free space to encourage debris recycling plants and integrate the concept of recycling with construction and demolition. A professional body of demolition contractors and experts (similar USA, UK, Germany) have to be set up in India, to have a collective approach.

Moreover, archiving of the plans of buildings must be given due importance so that while demolishing, the process becomes easier, efficient and hazard free.

Mohan Ramanathan B.Tech. MS (USA), Managing Director,Advanced Construction Technologies Pvt. ltd., Chennai, mohanact@gmail.com