  We present the development of a specialized concrete for neutron shielding at
neutron research facilities, based on the addition of hydrogen atoms in the
form of polyethylene and also B$_{4}$C for enhancing the neutron capture
properties of the concrete. We show information on the mechanical properties of
the concrete and the neutronics, in particular it's relevance to modern
spallation neutron sources, such as the European Spallation Source (ESS),
currently under construction in Lund, Sweden. The new concrete exhibits a 15%
lower mass density, a compressible strength of 50% relative to a standard
concrete and a significant increase in performance of shielding against MeV
neutrons and lower energies. The concrete could find application at the ESS in
for example common shielding components, individual beamline shielding and
instrument caves. Initial neutronic tests of the concrete, carried out at Lund
University, have also verified the performance in the MeV neutron energy range
and the results are presented.
