GROUND PENETRATING RADAR AS AN INVESTIGATIVE TOOL FOR CRACKING AND DETERIORATION ON BRIDGE SURFACES, DECKS, REBARS

Ground penetrating radar (GPR) is a valuable tool for geological, environmental, and geotechnical applications, including highways and bridges. As the state of Arkansas undergoes massive construction of new roads and bridges, this research seeks to explore GPR as an investigative tool for the evaluation of cracking and deterioration on bridge surfaces, decks, and rebars. Two main bridges at the University of Arkansas at Little Rock campus are the 28^th Street (Northbridge) and the 32^nd street (Southbridge). On both the Northbridge and Southbridge, four GPR profiles were mapped out for this survey, and the data were analyzed. The results obtained from the GPR profiles show 35% of the bridge surfaces and underneath have cracking and/or deterioration. Longitudinal cracks were more prevalent, followed by diagonal and transverse cracks. Three major factors which influenced the cracking/deterioration of these bridges were mainly mechanical, chemical, and thermal stresses. Based on the result, GPR tool gives a clear radargram of these cracks due to the high impedance contrasts. Delineating the location and extent of such deficiencies is an essential step in assessing the need for maintenance and repair of highways and bridges.