Assessment on the environmental temperature variation induced temperature and strain effects inside cement concrete pavements based on long-term FBG monitoring information

The internal information of pavement structure is difficult to be accurately obtained by mechanical theory due to the multimedia of component materials and the complex interfacial contacting conditions, and the lab tests are affected by model scale and simplification of loads. Therefore, it is of great significance to accurately obtain the internal information of the structure. The fiber Bragg grating (FBG) sensing technology has thus been adopted to monitor the long-term information of temperature fields and temperature variation induced strain inside the pavement structure. Based on the long-term monitoring data, statistical analysis aided with regression algorithms has been performed to establish the temperature prediction model at each depth of the cement concrete pavement. The results show a high quadratic polynomial correlation between pavement temperature and pavement depth. To confirm the effectiveness of the proposed models and techniques, finite element simulation analysis based on ABAQUS software is performed. The feasibility and accuracy of the developed pavement monitoring system for long-term continuous structural health monitoring is proved. The field data indicates that the heat transfer weakening effect due to the structural materials has a gradual lag in the time between the peaks and valleys of the temperatures at each layer of the structure. By analyzing the temperature variation induced strain field of the pavement structure, certain data references are provided for the preventive maintenance, design and construction of rigid pavement structures. The study provides scientific instructions for assess the performance of the pavement under long-term environmental temperature actions and efficient temperature prediction model for preventive control of the large temperature gradient induced deformation effect in rigid pavements in Gansu Province.