SHM and evaluation of a continuous reinforced concrete pavement

To assess the long-term behavior of a new concept of a continuous reinforced concrete pavement (CRCP), an SHM system was designed using 27 strain, 2 acceleration and 5 temperature FBG optical sensors, all embedded in concrete. The main objective was to monitor the performance of the reinforcement steel and concrete, considering vibrations and strains due to live loads and thermal effects. The test pavement was built on one of the most important highways in Mexico with nearly 50,000 vehicles per day, where 40 % are heavy vehicles. The CRCP has been evaluated under controlled and operational live loads, and dynamic responses have been correlated to temperature changes and thermal gradients. After almost 3 years of regular monitoring, it has been found that the FBG sensor system has been able to evaluate the structural evolution of the pavement. At present, structural changes have been identified due to mayor cracking as a result of combined thermal stresses, pavement deformations and dynamic loads. Stress changes and distributions have been measured, and although the pavement did not achieve the expected useful life; monitoring data has become a very useful data base to understand the pavement behavior and to redesign an operational cost-effective pavement. As for the CRCP performance, results show that the proposed design is not adequate for high loads and high traffic conditions. Pavement redesign must consider the use of more steel reinforcement to control cracking and should also take into account temperature gradients and the base–pavement interaction.