Study of the impact of heavy trucks on the smoothness of asphalt concrete pavement

Abstract

This article examines the significant increase in traffic flow on the 1315–1458 km section of the M-39 “Almaty–Bishkek–Tashkent–Shahrisabz–Termez” highway located in the southern region of the republic, and investigates the effect of heavy freight vehicles on the smoothness of asphalt concrete pavement, particularly the formation of wheel-path rutting. The study analyses the elastic and plastic deformations occurring in the pavement under heavy truck loads, the deterioration of pavement smoothness and the reduction in pavement service life. The longitudinal roughness of the 1360–1425 km section was surveyed in both directions with the “TRASSA” mobile road laboratory complex and evaluated against the International Roughness Index (IRI). The mean measured index is 1.76 m/km in the Tashkent–Termez direction and 1.49 m/km in the Termez–Tashkent direction, while 8.4 % and 3.7 % of the surveyed length respectively exceed the permissible value of 3 m/km established for category I roads; the maximum recorded value reaches 8.08 m/km. On this basis engineering recommendations were developed to improve the transport and operational condition of the pavement.