Counties cannot buy any materials that are used for highway or roadway construction, resurfacing, or maintenance from any foreign government, any company wholly owned or controlled by a foreign government, or any agency of a foreign government or company. Materials covered by the act include, but are not limited to, asphalt cement, asphalt emulsion, rock, aggregate, liquid and solid additives, sealers, and oils. This legislation is not applicable if materials made by American companies are of unsatisfactory condition, are not of sufficient quantity, or increase the overall project cost by five percent more than the overall project costs using materials produced by foreign companies. T.C.A. § 54-5-135.