A performance evaluation method of preformed joint sealant: Slip-down failure

Various preformed joint sealants (PJS) can be used for joint concrete pavement (JCP) to prevent the JCP from distresses such as pumping and faulting. Even though PJS have an important role in concrete pavement structures, most of the test methods that assess PJS focus on evaluating their basic mechanical and chemical properties rather than performance-related properties. In this study, a tester for PJS is developed and utilized to determine the resistant stiffness, which is considered to be a performance-related parameter, of PJS in transverse joints. The resistant stiffness is determined by dividing the peak force by the displacement; and the normalized value, which is used to simplify the relationship between the joint width and the sealant width, is determined by dividing the joint width by the sealant width. From laboratory tests performed on the developed tester, it is found that the resistant stiffness and normalized value are representative parameters that can be used to recommend the proper width of the joint, regardless of the joint width and joint type. Also, the relationship between the slip-down distress and the joint width, which is obtained from field survey results, can be utilized to recommend a minimum width for PJS.