DEVELOPMENT OF MAINTENANCE AND REHABILITATION INVESTMENT STRATEGY FOR FLEXIBLE PAVEMENTS

Abstract

Highways are playing an increasingly important role in transportation system of the country. The quality of roads is a critical indicator of a nation's economic vitality. Failure to maintain roads amounts to an act of dis-investment as it implies sacrifice of the past investment in roads. Obviously, maintenance of pavements and particularly the flexible pavements becomes an essential and vital phase of highway activity to retain the original investment and to keep the highway in serviceable condition by stretching the meagre budget as much as possible. The magnitude of work involved in maintenance is very large but the funds available are not enough to meet the requirements. The emphasis is needed to make the maintenance management more effective and efficient in order to programme the investments on pavements of selected road network so as to achieve optimal results. For this, priorities must be assigned to different road sections for maintenance and rehabilitation. In the present study, an effort has been made to analyse the data of certain flexible pavement sections to assess the needs for maintenance and rehabilitation of these sections located on different highways and in different regions. The parameters considered for the present study are deflection, roughness, rut depth, cracks, pot-holes and traffic volume & axle load. Four sections in the State of H.P. (on NH-21 & NH-22) and eight sections in the State of U.P. (on NH-2, SH-45 & MDR-121W) have been analysed for premonsoon and postmonsoon seasons. (iii) Analysis of data reveals that deflection on all test sections is greater than allowable deflection. Strengthening measures i.e. overlays are required to achieve adequate structural capacity. Overlays for 5 yr's, 10 yr's and 15 yr's periods are designed as per IRC : 37-1984 and MOST guidelines. For most of the test sections, roughness value is greater than allowable limit, so maintenance measure such as surface dressing is recommended for these sections in case overlaying is delayed. Need for corrective measures are determined based on the criteria of excessive rutting, cracking and pot-holes in the sections. Investment needs for maintenance and rehabilitation of different test sections based on the requirements of corrective and strengthening measures is. estimated as per the U.P.P.W.D. schedule of rates. Investment strategy (i.e. priority fixation to various sections) for maintenance and rehabilitation has been developed. Present study would be useful for taking decisions for maintenance & rehabilitation of flexible pavements rationally. Finally, it has been recommended that sufficient field data should be collected from different parts of the country on different pavement locations for developing maintenance and rehabilitation guidelines.