The Bruhat Bengaluru Mahanagara Palike (BBMP), which has a responsibility to fill potholes in the city, continues to use cold mix asphalt to fix potholes on roads during rains, despite it being a temporary solution. As the rains have resumed in Bengaluru over the last couple of days, citizens fear that they will have to contend with more potholes.
The civic body, which claims there are only 1,051 potholes in Bengaluru after the downpour which created waterlogging in many parts last month, had issued directions to its zonal officials to use cold mix asphalt when it was raining and later use hot mix asphalt to fill potholes.
However, motorists complain that the BBMP is yet to fill the potholes and many roads have been filled using cold mix asphalt and even using crushed stones in a haphazard manner.
Prasanna Kumar, a motorist who passes through Dairy Circle every day to reach Shanthinagar, said: “I recently saw the BBMP filling the potholes using just a mix of crushed stones and mud. This stretch become worse after a short spell of rain the next day.”
Another commuter Manohara Kumar said: “The BBMP is fooling people by saying they are filling potholes, but we see potholes being formed in the same spot within a few days after the civic body has filled the pothole”.
BBMP workers filling a pothole at Subhash Chandra Bose Road.
According to season
Meanwhile, BBMP officials say that both the cold mix asphalt and the hot mix asphalt, according to the season, are a good solution for potholes in the city. The cold mix asphalt mix is good during the monsoon since it is easy to prepare, compared to the hot mix asphalt.
“Owing to the rains, preparing the hot mix asphalt is not possible since it requires jelly and asphalt which are mixed and heated to 150 degrees Celsius and maintained at 100 degrees Celsius. But the cold mix asphalt is easy to prepare but does not last long. However, it is widely used during the rainy season,” a BBMP official said.
The BBMP has also proposed to set up a cold mix asphalt plant in the city, similar to the hot mix asphalt plant which has already been set up at Kannur, around 20 km from the city.
The Kannur plant was set up in an attempt to bring more accountability and reduce the BBMP’s dependence on contractors. Now the civic body is in the process of setting up a cold mix asphalt plant in Kengeri, for which they have called for a tender.
In the previous system, it was the contractor who provided the asphalt mix which could be of questionable quality, leaving the BBMP with no option but to take a gamble on the longevity of the patchwork. Now after the Kannur plant was set up, the civic body officials say more quality control was visible. They want to extend this similar procedure to the cold mix asphalt plant.
Differences in procedure
“In the hot mix asphalt process, the asphalt mix has to be maintained at a certain temperature. If the temperature drops, the mix cannot be used to fill potholes,” officials explained and said that the special vehicles are equipped to maintain the temperature for a maximum of four hours. “The hot mix asphalt from the plant can be transported to any part of the city within two hours,” officials claimed.
Cold mix asphalt can be prepared by mixing aggregates with bitumen emulsion at ambient temperature on the spot compared to the hot mix asphalt prepared at a temperature of 155 degrees Celsius, the official explained.
