Comparative Analysis of Concrete and Asphalt Pavement Damage on Trengguli-Kudus Road Using 2D-Resistivity and GPR Methods

Abstract In recent years, the Trengguli-Kudus Road in Demak, Central Java, Indonesia has frequently experienced damage, even after repeated repairs. This road is located on one of the main transportation routes on the island of Java, so it requires more attention and maintenance. This study aims to identify and compare road damage of concrete and asphalt pavement using geophysical methods, 2D-resistivity with Wenner-Schlumberger configuration and Ground Penetrating Radar (GPR) at KM 39+600 and 39+850. Secondary data from borehole logs and pit test results were also used as validation in the interpretation process. The types of damage identified from GPR processing results indicate that asphalt pavement showed signs of rutting, distortion, cracking, and settlement, while concrete pavement exhibited cracking and settlement. This settlement is also supported by the 3D resistivity cross-section, where the clay layer appears to dip southward, suggesting material movement toward the river. The suspected causes of recurrent damage at the study site are the characteristics of the soft subgrade and overloading. From the radargram response comparison, it is concluded that damage in concrete pavement is more clearly visible, consistent with field conditions and the stiffer nature of concrete, which is more prone to cracking. For national road with high traffic load, suggested that it is better to use concrete pavement as it is more rigid than asphalt. In this road, the subgrade maintaining also should be done to strengthen the pavement above it.