The clearance, replanning, redevelopment, rehabilitation and improvement of blighted and substandard areas shall be a public use and purpose for which the power of eminent domain may be exercised, tax moneys and other public funds expended and public credit pledged. The general assembly may authorize cities, towns, or local redevelopment agencies to undertake and carry out projects approved by the local legislative body for such uses and purposes including the acquisition in such areas of such properties as the local legislative body may deem necessary or proper to effectuate any of the purposes of this Article, although temporarily not required for such purposes, and the sale or other disposition of any such properties to private persons for private uses or to public bodies for public uses.