The flexible pavement is the most sought pavement in many countries like U.S, India etc mainly because of ease and low initial cost of construction and maintenance as compared to a concrete pavement. Due to the distresses caused in flexible pavements, it requires routine and periodic maintenance and strengthening in the form of added thickness. The Benkelman Beam Deflection (BBD) method as given in IRC:81-1997 is the commonly used methodology for the overlay design of the bituminous pavements in India. For a given bituminous road using the characteristic deflection and traffic, the overlay thickness is given. Recently, Indian Road Congress has published code of practice for strengthening of flexible pavement using falling weight deflectometer i.e. IRC:115-2014.The Falling Weight Deflectometer (FWD) has been regarded as an otherwise effective non-destructive tool for structural evaluation of pavements and is believed to be more realistic since it characterizes the pavement using the deflection bowl whereas BBD gives the simple characteristic deflection of the pavement. Since both deals with the overlay requirement of the pavement, this papers deals with comparative evaluation of overlay thickness requirement by both the code of practice. The test was conducted on a road built with control within the premises of CSIR-CRRI.
Contributors: Khan S, Nagabhushana M N, Tiwari D, & Jain P K.