Composite concrete material and method of making a composite concrete material

A composite concrete cover, comprising:

• a first concrete layer that has a first polymer and a plurality of reinforcing fibers;
• a second concrete layer that has a second polymer and said plurality of reinforcing fibers;
• a low density layer positioned between said first concrete layer and said second concrete layer, wherein said low density layer has a third polymer and has a filler material with a density of less than 400 kg/m3, and wherein said low density layer is less than 40% of a weight of said composite concrete cover and greater than 40% of a volume of said composite concrete cover;
• a first interface between said first concrete layer and said low density layer, wherein at least one polymer chain of said first polymer and at least one polymer chain of said third polymer are cross linked together;
• and
• a second interface between said second concrete layer and said low density layer, wherein at least one polymer chain of said second polymer and at least one polymer chain of said third polymer are cross linked together.

A method of manufacturing a low density composite concrete cover, comprising:

• mixing a polymer and at least one aggregate to form a polymer concrete mix, wherein said at least one aggregate has a filler material with a density less than 400 kg/m3;
• heating a form to at least 200° F., wherein said form has a predetermined shape and defines a volume;
• positioning a first concrete layer in said form, said first concrete layer having a first polymer and reinforcement fibers;
• pouring said polymer concrete mix on said first concrete layer, wherein a first interface is defined between said first concrete layer and said polymer concrete mix;
• positioning a second concrete layer on said polymer concrete mix, said second concrete layer having a second polymer and reinforcement fibers, wherein a second interface is defined between said second concrete layer and said polymer concrete mix;
• and
• pressing said first concrete layer, said polymer concrete mix, and said second concrete layer into said form with at least 80 psi of pressure for at least 6 minutes, wherein at least one polymer chain of said polymer concrete mix and said first polymer are cross linked at said first interface, and wherein at least one polymer chain of said polymer concrete mix and said second polymer are cross linked at said second interface.