Non-metallic building materials, namely, cement, concrete, mortar, pre-cast wall forms made of cement or concrete, concrete blocks, bricks, posts, slabs and panels made of cement or concrete; cement and mortar; materials for use in the construction, repair and maintenance of roads, namely, cement, concrete, rock, natural or artificial stone, cementitious, asphaltic, or bituminous substances, or materials made from such substances, all for use in roadmaking