Research On Evaluation Of The Service Performance Of The Pavement Structure

Road pavements normally suffer from conditions like temperature variation, water penetration and traffic loads, which may result in deterioration of the structure. The performance of the pavement degrades and its service life becomes shorter. So, continuous monitor and evaluation of the pavement structure and the service performance is necessary. It helps to diagnose the damage and gives repair suggestion in time, ensuring the service of the pavement.A scientific, applied and fast pavement structure health evaluation system is established in this thesis based on an intensive analysis on the cause and development of the common pavement damages. The system is operated by combining an inner sensor system and an outer non-destructive testing system. The change of the pavement structure was analyzed and summarized by means of monitoring the change of strain, temperature and humidity. A long-term health monitoring is performed on Hanyi freeway, and various factors on the system is analyzed in the situ monitoring on specifically section of it, and large numbers of data is obtained, then attempts to evaluate the pavement structure performance timely and forecast the damages. According to the results, following conclusions are obtained:(1) The temperature changes along with the seasons. The variation of temperature is mainly caused by the change of environments. The temperature distribution, temperature gradients and rate of variation changes with depth of the pavement. The relative humidity is also mainly affected by the environmental condition, and it changes with the environmental condition such as rain. The magnitude of the strain was changing at a small rate, and the corresponding curve was smooth. Sudden changes are not observed, and the strain variation was mainly caused by the change of temperature.(2) No damages are observed in the asphalt concrete, concrete foundation and the roadbed. It can be seen from the nondestructive testing system analysis that each layer of the pavement is even and the surface of each layer is flat, and the thickness of each layer is constant. No cracks detachments are observed. The temperature distribution curve is smooth as well, and the temperature variation is no bigger than 0.5℃on the surface of the pavement. It could be seen from the comprehensive analysis that the chosen section in which sensors are buried are in good condition, and no damage appeared.(3) The pavement structure health evaluation system could not only forecast the diseases but also acquire a comprehensive information about the damages, which included the type and causes of the damages.(4) The pavement structure health evaluation system could give a timely and effective monitor on the service performance of the pavement structure. It helps to constitute appropriate and applied scheme for maintenance and repair to the pavement.