In the present research programme, an effort has been made to develop the structural and roughness deterioration models for maintenance management of flexible pavements. These models have been developed utilizing the data of test sections located in the state of Uttar Pradesh (U.P.) and Himachal Pradesh (H.P.) of India. The data have been analysed for pre-monsoon and post-monsoon seasons for the years between 1980 and 1993. The overlays on the test sections with different types and thicknesses of materials were laid during 1985-1986 based on the analysis of data collected during 1980-1985. The parameters for developing the structural deterioration model considered are initial surface deflection (Do), surface deflection after the application of traffic loads (D), cumulative number of standard axles (CSA) and overlay thickness (H). The overlay thickness determination requires the data on allowable deflection (Da) and characteristic deflection (Dc) values. The parameters considered for developing the roughness deterioration model are initial roughness (RIo), increased roughness after the application of traffic loads (RI), cumulative number of standard axles (CSA) and overlay thickness (H). Overlay thickness determination requires the data on present value of roughness index (RIo) and allowable roughness index (RIa) of the resurfaced pavement. The applicability of the above models has been tested by taking the data of test sections located on State Highways and National Highways in U.P. State of India. It is hoped that the above models can be used in other situations for predicting the structural capacity and riding quality for a given number of cumulative number of standard axles during the design life of flexible pavements. The above models are also found to be useful for making decisions in the selection of bituminous materials in view of the exorbitant material cost. (A)
Abstract