A new method to evaluate the performance of sealants, used in rigid pavement joints, was developed. A special fixture was designed to transfer cyclic in-line deflection, applied by a testing machine, to cyclic normal and shear deflections on a sealant sandwiched between two-2 x 2 x 2 in. portland cement mortar cubes. The normal and shear deflections were applied simultaneously at a specific ratio controlled by the developed fixture. The new testing method simulates field conditions, where shear deflection is caused by vehicle loads while normal deflection is caused by slabs contraction or expansion due to temperature variation. The developed fixture was used to evaluate the performance of three commercially available one-component sealant types: (A, B, and C), A is a low modulus sealant, B is a self leveling type, while C is a sealant which is used with primer. The effect of joint width on sealant performance was investigated using two joint widths (0.25 in. and 0.75 in.), while the weathering effect was evaluated by exposing specimens to 50 cycles of rapid freezing and thawing prior to testing. / Master of Science