The equipment available for demolition and breaking has undergone several changes over the last couple of years
It is hard to imagine that an attachment to a giant machine can see so many innovations and novelties. And this is true of the demolition and breaking equipment. And more often than not, the new models that come into the market instantly replace the old ones. Yet these machines have remained inconspicuous and have received little recognition. One of the reasons for this is because India as a country is still a region ripe for development. The country’s vast land resources encourage construction, not destruction. In recent times, especially in Mumbai, scarcity of land has given way to redevelopment of existing buildings on a large scale. This process calls for reconstruction of residential or commercial buildings by demolition, if necessary, of the existing structure and construction of a new and higher building. And this is where various types of demolition tools come handy.
Harinder Jit Singh, president, Sandvik Construction India, says, “We have one of the youngest designed breakers in the
world. All the new models we launched last three years have replaced our old models. New designs are made considering
the latest technological inventions which are developed listening to customers. We use around 105 patents all across
our models. We assure our customer that they can complete their work more quickly by opting for Sandvik Breakers
– Bretec and Rammer.”
Using the right tool for the right application is very important. Companies involved in demolition and breaking need to
move out from applying one breaker for all breaking applications. The tool should be selected based on the amount of
breaking to be done and the level of breaking (waist above or waist below) and need to treat light chipping of concrete
(plaster removal) different from heavy duty breaking like slab breaking. Amit Uniyal, MD and CEO of Nagpur-based
Anika Drill Services, says, “When assessing the risks associated with demolition work we consider the structure to be
demolished and its structural integrity, method of demolition including the sequencing and schedule of work, and the layout of workplace. After this we decide on the equipment to be used and the skill and experience required by the people who will use it safely, the number of people that will be involved and local weather conditions.”
Demolition of a large structure involves understanding the site and the building drawing. During the site visit, actual
conditions are observed. “Then coming to the portion to be demolished, we consider the connection of that portion with
the entire building, and the parts that are affected or will be disturbed. If we notice any such thing, then all necessary
support is offered so as to prevent unexpected collapse of the structure,” says Uniyal.
Identifying hazards involves finding all things and considering situations that could potentially cause harm to people.
Common demolition hazards include: Unplanned structure collapse, falls from one level to another, falling objects, location
of above and underground essential services, exposure to hazardous chemicals, and dust, hazardous noise from equipments used in demolition work, and proximity of the building or structure being demolished to other buildings or structures.
Demolition equipment regularly undergoes testing in tough conditions. For instance, Atlas Copco has a range of demolition and breaking equipment that are ideal for small contracting assignments to hydraulic breakers that are deployed at rock quarries to bulk pulverisers. Nitin Lall, general manager, Atlas Copco Construction Equipment, says, “For us, demolition equipment
are mainly attachments. However, we have been meticulous in bringing out the latest drilling machines and constantly added
new equipment. Our pulverisers conceived for primary demolition of concrete and rebar ideally combine the characteristics of a demolition attachment with an excavated material pulveriser. The universal use of the DP demolition pulveriser
for concrete pulverisation in both primary and secondary demolition reduces both investment and operation costs.”
High reach arm is another traditional method of demolition. The threshold for defining a high reach demolition is when it reaches a height of more than 20 metres. This method is usually formed by a base machine (excavator, tank, engine, counterweights), a demolition arm consisting of three sections or by a telescopic boom and a primary tool attached to the base machine (crushers, shears, hammers). High reach demolition machines can be equipped with different tools to make
them suitable for executing demolitions of structures. This method is used on reinforced concrete, masonry, steel and
mixed material structures. The machines used in this type of demolition are not the only machines used in the process;
there must be additional components used for secondary operations such as crunching of material.
In all this, contractors ensure that the demolition equipment is flexible and ensure their high-performance while ensuring
they are low maintenance. Singh of Sandvik explains how. In terms of performance, their breaker designers have allowed breakers to take more power from the excavator and convert them to output power in an efficient way. The design, material technology, manufacturing process, safety features inbuilt in the breakers, etc, match with massive increase in allowed input energy. For instance, the Sandvik – Breatec L20C allows for 51kw input power. Other breakers in the industry allow similar breakers to get 40kw to 48Kw only. This implies that a customer can complete a particular job in less time. In terms of low maintenance, the following features reduce maintenance cost of breakers. a) Patented tool retaining mechanism eliminates 8-10 spare parts, and b) Idle blow protection, auto grease option, special front hose design, dust protection seal, front head design, tie rod design, etc help in keeping costs low for customers.
Hydraulically-operated excavators and loaders can be fitted with various attachments for demolition work. Excavator
buckets, boom-mounted hydraulic percussion breakers and pusher arm equipment have been successfully used with these machines. The main advantages of such machines are that they are extremely mobile, have a high output, and are able to work on vertical faces and floors above standing level. Their disadvantages are that the machines need adequate access, a firm and relatively flat base to work from, and can only work within the reach of their booms. To operate these machines efficiently, the length of boom when fully extended should be at least 1.5 metres above the height of the building being demolished. Pneumatic breakers can be used on semisolid rock, asphalt cutting as well as concrete, but the vibration levels are high.
There are quite a few technological advancements in demolition equipment that enable them to deliver maximum reach and stability with little vibration and noise. Singh says that sound and vibrations are extremely low in Sandvik breakers because of the following two major innovations:
a) Excellent vibration dampening mechanism. The percussion mechanism is completely surrounded by plastic pads inside outer housing.
b) Housing has only 2-3 holes in the retaining pin and bush area. Means one of the most silenced breakers with respect
to power. Other normal traditional breakers have 8-10 holes.
Uniyal of Anika Drill Services explains the type of equipment that will transform the demolition/breaking industry. “The
hydraulic jaw crusher and the hydro demolition that runs on water and helps in cutting and chipping concrete is new in
India. They can do the job well and are efficient.”
While some in the industry consider hydraulic breakers as passé, they praise the preference for pneumatic and electric
machines. “Pneumatic breakers can be used on semi-solid rock, asphalt cutting as well as concrete, but the vibration
levels are high. They should be preferred in complete structure demolition,” says Uniyal. “Controlled blasting will always
remain the cheapest method of demolishing complete structures.”