The governing body, in any ordinance for the paving of a street or highway, may designate two or more kinds of material to be used, and may advertise for proposals for the work of making such improvement with each of the materials so designated. The governing body after receiving such proposals may determine which of the materials shall be used. The governing body may solicit bids for any such work before the final passage of the improvement ordinance and announce the same at any hearing accorded under such ordinance to persons interested.