Abstract: To produce a composite building unit having a polymer-cladded surface, a polymerizable resin binder and a blend of filler particles are combined to provide a resin binder/filler mixture which is deposited in a mold. A concrete substrate is then positioned in the mold with a face surface contacting a transition layer comprising a lightly filled resin binder/filler layer portion of the deposited mixture overlying a highly filled resin binder/filler layer portion of the deposited mixture. The resin binder in the transition layer migrates into pockets and pores in the substrate face surface to create mechanical locks when the resin binder is cured. These locks, in addition to chemical bonding, serve to permanently affix the cured resin binder as a surface cladding to the substrate. Initiators may be added to the resin binder to promote thermal and/or UV radiation cures thereof.

Abstract: Composites useful in building structures such as floor tiles, are prepared having a very strong bond between a highly filled polymeric surface layer and a cementitious backing. The composite comprises: a first layer of solid particles intimately mixed with a polymeric binder; a second layer of an organic and/or inorganic solid; and a transitional layer located between the first and second layers comprising both the polymeric binder and the organic and/or inorganic solids wherein the polymeric binder is contained in pockets within the organic and/or inorganic solid and at least some of the pockets of the polymeric binder extend from the first layer.