Interior models suggest that the likelihood of Kepler-452b being a rocky planet is somewhere between 49 to 62 percent. The host star of Kepler-452b has ~1.11 times the radius and ~1.037 times the mass of the Sun, and its estimated effective temperature is 5757 ± 85 K. Furthermore, the host star of Kepler-452b is estimated to be 6 ± 2 billion years old. Because Kepler-452b is expected to have a relatively low-mass and its host star is relatively faint, measuring the mass of Kepler-452b through radial velocity observations will be unlikely in the near future.
Jenkins et al. (2015), "Discovery and Validation of Kepler-452b: A 1.6-Re Super Earth Exoplanet in the Habitable Zone of a G2 Star", arXiv:1507.06723 [astro-ph.EP]