the material used to fill the cavity between the two legs will adhere to the surface of the prepared floor surface furthermore the openings 42 prevent the units from floating in the material used to fill the cavities the 34 u 34 shaped unit is preferably manufactured in 2 0 m lengths and may be cut at the site to make special ornamental forms the 34 u 34 shaped unit of the present invention may also have two additional design features the unit may be manufactured with small partitions 43 in order to reinforce the material used to fill the cavities thereby decreasing the likelihood that the material will crack the partitions are placed at regular intervals in the 34 u 34 shaped unit for example one every 60 cm additionally the 34 u 34 shaped unit may incorporate a plurality of openings through its legs 41 these openings serve several purposes 1 they increase the surface area upon which the material poured into the cavities and adjacent to the unit may adhere to 2 they increase the unit 39 s resistance to deformation from the pressure of the material poured into the cavities by equalizing the pressure between the cavities and 3 they prevent the unit from.