Polyurethane concrete sandwich components and method for preparing the same

A method for manufacturing a polyurethane concrete sandwich component comprising a first surface layer, a second surface layer and a polyurethane sandwich layer, wherein the first surface layer and the second surface layer are respectively located on two surfaces of the polyurethane sandwich layer, and at least one of the first surface layer and the second surface layer is a concrete layer, the method comprising:

• i) forming the first surface layer and the second surface layer in molds, wherein the first surface layer and the second surface layer are arranged opposite to each other, and the opposite faces of the first surface layer and the second surface layer are arranged spaced apart from each other to form a cavity;
• ii) making the two surface layers arranged opposite to each other in the molds obtained from step i), as a whole, form an angle of 1-45° relative to the horizontal plane;
• iii) applying a polyurethane reaction system into the cavity formed in step i);
• and
• iv) solidifying the polyurethane reaction system in the cavity to form a polyurethane foam,
• wherein the cavity is formed by a method comprising:
• a) forming the first surface layer in a first mold and the second surface layer in a second mold, wherein the first mold and the second mold each have one surface that is unclosed, wherein at least one of the first mold and the second mold have a wall height greater than the thickness of the surface layer formed in the molds;
• b) arranging the first surface layer located in the first mold and the second surface layer located in the second mold opposite to each other,
• c) contacting the edges of the unclosed surfaces of the first mold and the second mold with each other, and
• d) sealing the edges.