A new method to evaluate the performance of sealants used in rigid pavement joints
was developed. A special fixture, attached to a servo-hydraulic testing machine, was designed
to transfer applied cyclic shear deflection to a sealant sandwiched between two 51 x 51 x 51
mm portland cement concrete (PCC) cubes at a constant horizontal deflection. The new
testing method simulates field conditions where shear deflection is caused by vehicular
loading, while horizontal deflection is caused by slabs contraction or expansion due to
temperature variation. Two commercially available, a low modulus silicone (sealant A) and
a polyurethane (sealant B), one-component sealant types were evaluated at different joint
widths, number of freezing and thawing cycles, and horizontal deflections. Two types of
aggregates were used in the PCC mixes to evaluate the effect of aggregate on sealant
performance. A limited number of specimens were evaluated for sealant failure using X-ray
photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Dynamic Shear
Rheometer (DSR) was used to estimate the viscoelastic properties of sealants.
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