Exhibit 3.28(a)

CERTIFICATE OF FORMATION FILEO OF Sec 3fice of the te of Texa ATLAS REDI-MIX, LLC “sr 21 2009 Corporations Section ARTICLE I The entity being formed is a limited liability company. The name of the entity is Atlas Redi-Mix, LLC. ARTICLE II The initial registered agent is Capitol Corporate Services, Inc.. The business address of the registered agent and the registered office address is 800 Brazos, Suite 400, Austin, Texas 770l. ARTICLE III The limited liability company will not have managers. The company will be governed by its member, and the name and address of the initial member is set forth below. Alberta Investments, Inc., 2925 Briarpark, Suite 1050 a Texas corporation Houston, Texas 77042 ARTICLE IV The purpose for which the company is formed is for the transaction of any and all lawful purposes for which a limited liability company may be organized under the Texas Business Organizations Code, ARTICLE V The name and address of the organizer is Stephanie Collins, 2925 Briarpark, Suite 1050, Houston, Texas 77042. ARTICLE VI This document becomes effective when the document is filed by the Secretary of State. The undersigned signs this document subject to the penalties imposed by law for the submission of a materially false or fraudulent instrument. Date: May2l,2009 By: Name: Stephanie Collins Title: Organizer P:\CorpSec\Maintenance\Atlas Redi Mix\Cert of Formationdoc