AAPT/ISAP International forum: Recent advances in pavement engineering in India

In the last two decades, India has provided impetus towards building a robust national highways road network through the aegis of the National Highway Authority of India. In addition, other categories of roads such as state highways, district and village roads are being constructed through agencies at the state and district levels. Most of these road networks are predominantly bituminous in nature, and the Indian highway engineers are adopting themselves to new technologies as the construction is proceeding at a brisk pace. It is expected that all the planned road network augmentation will come to an end during the next decade. Needless to say, the maintenance of the constructed highways and widening and strengthening will continue as the country's economy grows. The Indian highway engineers face considerable challenges during this nation building activity. Such challenges stem from the diverse temperature zones and geographical areas of India. The nature of subgrade varies considerably across the country and coupled with a large intensity of traffic loading (high tire pressures with large number of repetitions), bituminous pavement design is a challenging task in India. Also, the design paradigms suited for the plains of the country cannot be applied to the high altitude regions, especially for hill road constructions at the Himalayas. Since most of the highway construction is through toll and annuity based build-operate-transfer method, the necessity to predict the pavement deterioration during the design period is required and this involves sophisticated pavement prediction models along with a requirement for a large amount of pavement performance data. This workshop aims to present the recent advances in pavement engineering in India. This workshop has five presentations. The first presentation details the investigations related to the development of specifications for unmodified binders. A country-wide effort to collect binder data was initiated by the Bureau of Indian Standards, Government of India and this resulted in new viscosity-based specification for India. The performance grade properties of the binders were also collected and hopefully with the pavement performance data to be collected from the field, India can rationalize the binder specifications specific to Indian conditions in the near future. The second presentation details the history of pavement performance studies and how such studies have resulted in robust mechanistic-empirical based pavement design procedures. The background of the Indian Roads Congress guidelines released in 2012 is presented here. The third presentation documents the challenges faced in construction of roads in high altitude areas and rough terrain along the Indian borders with a few case studies. Such areas of road construction are entrusted to the Border Roads Organization, an unarmed and non-combatant force integral to the Armed Forces with men in uniform executing the construction. Taking into account the issues related to expansive soils in road construction, indigenous initiatives towards soil stabilisation are presented in the fourth presentation. The final presentation details some of the initial trials related to warm mix asphalt and the new guidelines released by the Indian Roads Congress related to the same.