Development And Performance Research On Strain Sensor Based On FBG For Asphalt Pavement

The road is the link of communion and one of the important symbols of economy development among countries or regions. Pavement which is the main component of a road withstands directly the fast moving vehicle load and resists all kinds of bad natural condition. As the number of vehicles increases suddenly and larger-scale, the road surface faces a stern test and is often damaged. The efficiency and the traffic safety have been affected directly. Therefore, it is very important to study the load function and the strain transmission rules between the different pavement structures.The optical fiber grating sensor is a kind of new sensor which has developed since the 1990s. Many FBG sensors have been used in civil engineering for structure monitoring in the last few years. However, the bare optical fiber grating can't adapt to the extensive construction request of civil engineering, so the bare diffraction grating must be packaged first. Therefore, the optical fiber grating sensor packaged craft becomes the key question for application in civil engineering. In view of the asphalt pavement strain test, one kind of optical fiber Bragg sensor based on the thermoplastic resin polypropylene has been proposed in this article,a real-time monitoring of the entire packaged process has been made by a demodulator,and then the mechanics performance, the microscopic structure, and properties of sensor have also been lucubrated. And then we get the tensile strength, the compressive strength and the elasticity coefficient of the sensor, the caking situation between the FBG and the packaged material, the sensor sensitivity coefficient and the redundant performance.PP - OFBG strain sensors have been separately buried to the concrete pillar and the asphalt concrete beam. We get the continuous 7 day-long early solidifications situation of the concrete, afterwards the concrete pillar had been carried on the axle center compressive test. Through the experiment, we can see that the caking and the coordinated distortion performance between packaged material and FBG is quite well, and also well between the FBG sensor and the concrete pillar. And then we get the strains of the asphalt beam under the static and dynamic loads through MTS. The sensor module is about 1GPa which is similar to the material of asphalt concrete pavement, and it can coordinate with the beam distortion, while the sensor weary performance very is also well. So it is suitable for the strain test and long-term monitoring for asphalt concrete pavement.Finally, we get the strains of pavement with the sensor buried into the pavement through finite element software ANSYS and then we compare strains with and without sensors. In addition, we compare the strains by different types of sensors with the strains of pavement with no sensors, and it is discovered that PP - OFBG strain sensor has its unique superiority.