  We present results of a long-baseline interferometry campaign using the PAVO
beam combiner at the CHARA Array to measure the angular sizes of five
main-sequence stars, one subgiant and four red giant stars for which solar-like
oscillations have been detected by either Kepler or CoRoT. By combining
interferometric angular diameters, Hipparcos parallaxes, asteroseismic
densities, bolometric fluxes and high-resolution spectroscopy we derive a full
set of near model-independent fundamental properties for the sample. We first
use these properties to test asteroseismic scaling relations for the frequency
of maximum power (nu_max) and the large frequency separation (Delta_nu). We
find excellent agreement within the observational uncertainties, and
empirically show that simple estimates of asteroseismic radii for main-sequence
stars are accurate to <~4%. We furthermore find good agreement of our measured
effective temperatures with spectroscopic and photometric estimates with mean
deviations for stars between T_eff = 4600-6200 K of -22+/-32 K (with a scatter
of 97K) and -58+/-31 K (with a scatter of 93 K), respectively. Finally we
present a first comparison with evolutionary models, and find differences
between observed and theoretical properties for the metal-rich main-sequence
star HD173701. We conclude that the constraints presented in this study will
have strong potential for testing stellar model physics, in particular when
combined with detailed modelling of individual oscillation frequencies.
