The way forward: NITTTR study suggests 20-year preservation plan for city roads

The study notes that an effort has been made to develop the “pavement maintenance management system” for Chandigarh roads to not only minimise the maintenance cost but also to maximise the lifespan of the road.

“A good maintenance management system should never allow the deterioration to the extent that there is a need for rehabilitation,” the study says.

Professor Ajay Duggal, from NITTTR, states that here in Chandigarh, road agencies just keep applying an additional layer of bitumen on the broken roads after a particular time without periodically maintaining them.

“Just a spray done periodically after routine inspection can help road restore its original life. Why to wait for further deterioration to recarpet them again and again without actually identifying and rectifying the faults underneath?” he says. Following a condition survey and inspection of selected roads done by the students of engineering at NITTTR, a module of pavement maintenance management system has been proposed for 20 years. “Fog spray and slurry seals” are to be used for road maintenance, it is recommended. The spray helps increase the life of roads.

WHAT IS THIS SPRAY AND WHAT IS THE 20-YEAR MODULE?
While fog spray is a light application of diluted bitumen emulsion to the road surface, slurry seal too is the application of a mixture of water, asphalt emulsion, aggregate and additives to the road surface as a maintenance measure.

Usually, the road agencies just lay an additional layer of bitumen every time when a road erodes. But timely application of these sprays can help not just in saving the life of the road but a lot of public funds as well. However, the engineering wing prefers to spend more funds and puts in the additional bituminous layer which doesn’t serve the purpose.

In the maintenance module, it is suggested that in the first year, the application of fog spray and slurry seal (15mm) should be given. The application of fog spray will get repeated during the process of third year. In fifth year, the application of slurry seal (15 mm) is required and then in the interval of two years, the act of applying fog spray is supposed to be continued up to 11th year. In the 11th year, slurry seal be also incorporated. From 11th year onwards in every two years, the application of fog spray is required to be done up to 16th year.

During the phase of 17th year, slurry seal be added simultaneously. Keeping up with the continuity up to 20th year, one fog spray and slurry seal be done.

Under the system, an “optimum maintenance and rehabilitation strategy” for all road sections has been chalked out. The study says that development of a “pavement maintenance management system” will also enable the engineers and decision makers to define the requirement of budget to maintain the road network at an acceptable level of serviceability.

ROAD AGENCY IS SPENDING 1.3 TIMES MORE
The teams under NITTTR also studied the existing maintenance practices and proposed maintenance management system and the cost involved in both. “The cost comparison of the two practices clearly shows that by using existing maintenance practices, the road agency spends about 1.3 times more than the cost of proposed maintenance management system,” the study specifies.

“There will be a huge net saving in cost of suggested management system module as compared to the existing practice. The proposed management system can be affirmed as a cost-effective maintenance strategy. In addition, better serviceability is also expected. The average cost per year for 1 km of V6 road reduces to nearly Rs 2.9 lakh as compared to Rs 3.8 lakh by conventional practice,” the study adds.

It is stated that the need for development of maintenance management system is extremely necessary for roads in a developing country like India. “The PMMS should be initiated to serve and protect the Chandigarh roads. The roads should be maintained at the appropriate time to enable the road to function at the required level of service and to extend its lifespan,” the study says. The rectification and preservation plan, it is said, should not only provide an effective solution but also be economical.
As a stop-gap measure, some agencies choose to allow roads to erode to gravel, which would be costlier than consistently maintained road over the long term.

Due to lack in proper planning, design and management of roads, the agencies generally resort to the same rehabilitation measure without taking into consideration different alternatives that could be resorted to to rectify the different defects effectively, the study observes.

CRACKS SHOULD BE FILLED AS Soon as possible
In order to prevent rapid degradation, periodic survey of road condition should be carried out and the cracks should be filled at the beginning of their occurrence. It is stated that drainage system should be checked regularly.