Page 172 - CW E-Magazine (24-12-2024)

Free to Die

Joints on roads and bridges: How to fi x the

problems

This column (to appear in the fourth issue of every month) is all about openly sharing
expertise and knowhow with our readers, regardless of industry, product or service.
The aim is plant the seeds of inspiration, strengthen the knowledge base, and hopefully,
lead to new opportunities and innovations.
While the column is being rolled out with the ideas of Prof. V.C. Malshe, an academi-
cian, researcher, innovator, consultant and businessman, it is open to one all. Simply
write to editorial@chemicalweekly.com. (If you would rather speak informally, that
too can be arranged).

All travelers on roads and bridges have experienced a regular thud while driving at
high speeds. It is felt more on bridges. I once heard our honorable minister, Mr. Nitin
Gadkari telling some interviewer if there was a way to avoid it, he could implement it.

Roads
Concrete roads make commercial sense because of their long service life and low maintenance cost. The initial cost is
high. The time required to start using the road is also long due to long curing time. But all this is acceptable for economic
reasons. The problem is the expansion joints. Concrete has a fi nite coeffi cient of thermal expansion. The temperature variation
across seasons in different parts of the country demands the use of an expansion joint at certain distance. Even though these
joints are fi lled with an elastic material, it wears out, expands, contracts and projects out of the surface when the slab expands
and fi lls up the gap. In colder climate, the slab shrinks, and the elastic fi ller depresses between the joint. In either case, a pass-
ing four-wheeler experiences a periodic “thud”. Depending on the speed of the vehicle, this frequency is high and irritating
to the driver and occupants alike. It also leads to damage of the suspension of the vehicle.

Bridges
Bridges also have expansion joints. At A note from the author
times, the joints are unsupported. Whenever I recently read about a book by Todd Henry. The title
a heavy vehicle passes over the bridge, there was ‘Die Empty.’ There was no need to buy and read the
is a very loud noise and jerk to the vehicle. book. Just one statement was enough to understand what was
The noise on bridges is much louder com- meant. It was something that made me think and seriously
pared to road joints. The reason is the can- consider writing this column.
tilever joint gets slightly depressed when the
front wheels of the four-wheeler reach the I have been an innovator all my life. I have put several ideas in prac-
end of the arch. The other side of the arch tice in my industrial career. But there were several that could not be
after the joint remains slightly higher and the implemented because I was not in the relevant industry, or I was ahead of
speeding wheels strike this raised surface. the times. I fi led several patents, got them, maintained them for their full
Depending on the speed and load of the life with my own resources.
vehicle, the intensity of the sound can
change. For large trucks with 20-24 tonnes As I approach my 78th birthday, I thought of penning down some
load, this impact may be too harsh for even ideas that could be used by companies, governments, individuals, alike.
the tires to sustain the shock. The primary I have no fi nancial expectations because patents have either expired or
cause of the noise is two impacts of the pair have not been maintained.
of tires on the joint and it is separated by few I present these to the world to make use of. Several have been
milliseconds depending on the speed of the communicated to senior government offi cials but seem to have been fi ltered
vehicle. This also poses a risk of damage to out by the administration. Hopefully, thiss will change. V.C. Malshe
tires.

172 Chemical Weekly December 24, 2024

Contents Index to Advertisers Index to Products Advertised