The assessment of the bond strength and cohesion among various layers is an essential element in asphalt construction processes, as it directly influences the performance and stability of roads. This paper aims to investigate the interface bond between the overlay layer and the underlying layer with a modified stress absorbing membrane interlayer (SAMI) incorporating Low Density Polyethylene (LDPE). Shear bond strength test was used to evaluate the performance of SAMI mixtures. Several blends of SAMI were prepared and tested at 25 ℃, where LDPE pellets were used as an additive to the controlling SAMI mixture in proportions of 2, 4, and 6%. For additional understanding, the relationship between shear strength and displacement was clarified, and the results showed a gradual improvement in the bonding process at the interface as the percentage of LDPE used increased up to 4% in terms of the total area under the curve, and up to 6% in term of highest shear strength. It was found that the greatest peak shear strength occurred when the mixture had a percentage of LDPE equal to 6%, which enhances interface bonds between asphalt layers. On the other hand, the area under the curve was calculated to characterize the relationship between shear strength and displacement and to assess the ability of the SAMI to absorb or mitigate the stresses before unbonding. The results showed that the 4% percentage of LDPE has the most significant area under the curve, which has the highest total area ​​before and after the peak (7.2 MPa/mm), which indicates the highest delay to unbond at the interface before crack initiation. It is worth mentioning that incorporating LDPE can enhance the SAMI ability in terms of bonding when the optimum percentage is carefully selected.