When it comes to bridges or any other man-made structures like buildings, they all have an estimated lifetime after which they start to show signs of wear and tear. However, the signs can be delayed for much longer if the structure is given proper periodic maintenance and the construction of the structure using quality materials.
With the emergence of innovative ways and materials in the construction field, it is currently possible to build structures that are more strong and durable than the ones constructed long before. But even the newly constructed structures are collapsing after or during the construction phase but some of the old ones still stand intact, therefore, this raises a question about the integrity of the structure.
The Old and New
Here we describe two bridges in Kerala that both gained significant popularity in recent times. One is the Nagampadam Railway Overbridge in Kottayam and the other one is the Palarivattom Flyover in Kochi. What makes them popular is their age differences in construction.
The Nagampadam railway over-bridge was built in 1953. This bridge was recently scheduled for demolition in April 2019 by using controlled explosives. But what happened? The bridge was not even shaken by the explosives and it remained intact thus making the demolition process a failure.
Whereas the Palarivattom Flyover which completed construction in 2016 over a period of two years started to show the serious formation of cracks on the surface within 3 years.
Image credit: The Hindu
What is the reason
The exact reasons for why the explosives didn’t work for the Nagampadam bridge is not known but it has to do due to its build quality. It is quite interesting to know that the 65-year-old structure was able to withstand the controlled explosive session not once but twice on the same day, after which the attempt was halted and postponed.
In the case of palarivattom flyover, the formation of cracks was found out by a study report given by experts from IIT Madras. As per their reports, several parts of the flyover were constructed using low-quality concrete, which resulted in the crack formation.
The irony is that the Edappally flyover and Palarivattom flyover were built around the same time, but Edappally flyover remains intact with no issues, however, both structures were constructed by different companies.
Need for better practices
The reasons for premature collapsing of any structure is ineffective construction processes that include the use of materials that do not fall under the recommended standard or may be of low quality. Both the structures show us what happens when the construction is done through efficient engineering skills and use of materials as per the recommended industry standard. This is the same case applied to when constructing homes.
We all know that TMT steel is the most preferred material for building homes. These particular type of steel bars are classified into grades and for a reason. Each grade is used for each type of construction design.
For homes and small buildings, the Fe 415 is the recommended grade by engineers because of its optimum strength and uncompromised ductility ratio whereas the higher grades are used for structures like bridges, dams etc that require higher tensile strength.
To reduce the occurrence of frequent collapsing issues of the structures, it is very important for constructing the structures using premium quality materials as per industry standards and doing maintenance periodically. If all the procedures are done correctly, it will ensure the longevity of the structure.