  FU Orionis-type objects (FUors) are low-mass pre-main sequence stars
undergoing a temporary, but significant increase of mass accretion rate from
the circumstellar disk onto the protostar. It is not yet clear what triggers
the accretion bursts and whether the disks of FUors are in any way different
from disks of non-bursting young stellar objects. Motivated by this, we
conducted a 1.3 mm continuum survey of ten FUors and FUor-like objects with
ALMA, using both the 7 m array and the 12 m array in two different
configurations to recover emission at the widest possible range of spatial
scales. We detected all targeted sources and several nearby objects as well. To
constrain the disk structure, we fit the data with models of increasing
complexity from 2D Gaussian to radiative transfer, enabling comparison with
other samples modeled in a similar way. The radiative transfer modeling gives
disk masses that are significantly larger than what is obtained from the
measured millimeter fluxes assuming optically thin emission, suggesting that
the FUor disks are optically thick at this wavelength. In comparison with
samples of regular Class II and Class I objects, the disks of FUors are
typically a factor of 2.9-4.4 more massive and a factor of 1.5-4.7 smaller in
size. A significant fraction of them (65-70%) may be gravitationally unstable.
