Analysis of Perpetual Asphalt Pavement Response under Heavy Loads in Northeast Area of China

Abstract

Severe rutting, cracks and moisture damage are presented on conventional semi-rigid base asphalt pavements not long after completed in China. This phenomenon indicates that conventional philosophy on pavement design could not meet more and more frequent and heavy vehicle. With high structural capacity for high traffic volume and heavy loads, the Perpetual Asphalt Pavements (PAPs) solve those problems well. Meanwhile they need minimal or no major structural rehabilitation and/or reconstruction exercises in their life, which ensures low user-delay. Three PAPs, including semi-rigid base asphalt pavement, flexible base asphalt pavement, and combined base asphalt pavement, are put forward for the northeast area in China considering its climate, traffic characteristic. Finite element method is utilized to analyze response of PAPs under heavy loads. Two key factors, i.e. tensile horizontal strains at the bottom of asphalt layers and compressive vertical strains are investigated. Also the capacities of the structures on bearing overloading are estimated. Four types of wheel and axle, including single axle and single tire, single axle and dual tires, dual axles and dual tires, and tri axles and dual tires are adopted in finite element models. The shapes of tire-pavement contact area are either circular or rectangular to simulate standard load or overloading respectively. When rectangular shapes are adopted, the contact area sizes and the distribution of pressure are varied. Conventional asphalt concrete and high modulus asphalt concrete are adopted. Simulations are done. The competences of the three pavement structures on fulfilling long lives are evaluated.