The Influence of CBR Value and Overloading on Flexible Pavement Mechanistic Response

摘要

Flexible pavement distresses are often caused by overloading with the combination of other factors, such as subgrade strength. Therefore, this study was conducted to investigate and analyze the effect of subgrade strength on flexible pavement mechanistic response with normal traffic loading and overloading scenario (25% to 100%) using KENPAVE software. CBR was varied from the range 3% to 10% with an increase of every 0,5%. Horizontal tensile strain was then used to estimate pavement fatigue life (Nf) and vertical tensile strain was then used to estimate pavement rutting life (Nr). The results of mechanistic responses reveal that the horizontal tensile strain and vertical compressive strain all decrease with increasing subgrade CBR value. The addition of load will increase the pressure that the vehicle distributes to the pavement, so that the horizontal tensile strain and vertical compressive strain will be higher. Nf and Nd all increase with decreasing of horizontal tensile strain and vertical compressive strain, which implies that higher CBR value will increase Nf and Nd. Rutting occurs at CBR 3% to 7,5% with the overloading of 75% and 100% while fatigue cracking occurs at CBR 3% to 9,5% with the overloading of 50, 75%, and 100%.