Comparitive LCA three highway paving technologies used in India: bituminous hot mix, bituminous warm mix and concrete pavements
Student name: Mr Niloy Sarkar
Guide: Dr Suresh Jain
Year of completion: 2012
Host Organisation: Central Road Research Institute (CRRI)
Supervisor (Host Organisation): Ms Kirti Bhandari
Abstract: Roads, especially national highways forms an integral part of India’s transport infrastructure. Accounting
for only 1.7% of the total road length but carrying 40% of all surface traffic Currently in India the predominant type
of highways are the bituminous hot mix type while new, more environmentally friendly and cost effective types have
been proposed such as the bituminous warm mix (additives to reduce the mix temperature) and concrete pavement.
This paper compares the merits and demerits of each pavement type by conducting a comparative LCA using the
software Simapro 7.3. Construction norms and specifications were determined using official manuals and inventory
was prepared based on the case study of a section of NH-4 between Belgoan and Maharashtra border. The
inventory prepared in accordance to the data was than fed into the software to conduct an LCA. Internal databases
of the software were also modified based on literature to better simulate for Indian conditions.
For impact assessment the tool Eco-indicator 99 was used with internal default weightage for the inventory
of raw materials and emissions. Impact assessment was based on three categories; human health, ecological
damage, and bulk resource usage, each with several sub-categories. It was found that the warm mix despite having
a lower mixing temperature had a slightly higher impact in the long term, this was primarily due to the manufacture
of synthetic zeolites which will be replaced with less polluting natural zeolites if large scale construction is
approved in India. Concrete pavements excelled in all impact categories apart from usage of bulk resources, but
overall they had a lesser impact score. Considering all additional categories which could not be factored in the LCA
it was concluded that warm mix pavement and more so concrete pavements are the overall better choice.
