This Act requires that for every public works contract or aggregate of public works contracts relating to a project in excess of $500,000 for new construction (including painting and decorating) or $45,000 for alteration, repair, renovation, rehabilitation, demolition or reconstruction (including painting and decorating of buildings or works) and which is paid for, in whole or in part, with public funds, which requires or involves the employment of mechanics and/or laborers shall contain a provision requiring the payment of the prevailing wage.