Exhibit 4.18.1


                                AMENDMENT NO. 1

                     TO LIMITED LIABILITY COMPANY AGREEMENT


         AMENDMENT NO. 1 TO LIMITED LIABILITY COMPANY AGREEMENT OF READY MIX
USA, LLC, a Delaware limited liability company ("Company"), effective as of
September 1, 2005 (this "Amendment"), by and between Company, CEMEX SOUTHEAST
HOLDINGS, LLC, a Delaware limited liability company ("Cemex"), READY MIX USA,
INC., an Alabama corporation ("RMUSA"), and solely for the purposes set forth
in Section 9.6 thereof, CEMEX, INC., a Louisiana corporation. Capitalized terms
used herein but not otherwise defined shall have the meaning ascribed to such
terms in the LLC Agreement (as defined below).

                                  WITNESSETH:

         WHEREAS, the Company, Cemex and RMUSA desire to amend the Limited
Liability Company Agreement of the Company, effective as of July 1, 2005 (the
"LLC Agreement");

         WHEREAS, Company and RMC Mid-Atlantic, LLC, a South Carolina limited
liability company and an Affiliate of Cemex ("RMC"), have entered into an Asset
Purchase Agreement, dated, September 1, 2005 (the "Asset Purchase Agreement"),
whereby (a) Company will purchase from RMC, and RMC will assign and delegate to
Company, certain assets and liabilities of RMC in accordance with the terms of
the Asset Purchase Agreement and (b) Company will be indemnified;

         WHEREAS, Section 8.2(b)(x) of the LLC Agreement provides that the LLC
Agreement may be amended with prior Board approval, which approval has been
granted by the Board; and

         WHEREAS, the Company, Cemex and RMUSA have agreed to amend certain
provisions of the LLC Agreement on the terms and conditions set forth in this
Amendment.

         NOW, THEREFORE, in consideration of the foregoing and the mutual
covenants and agreements contained in the LLC Agreement and this Amendment, the
receipt, adequacy and sufficiency of which are hereby acknowledged, and
intending to be legally bound hereby, the Company, Cemex and RMUSA hereby agree
as follows:

                                   ARTICLE I

                   AMENDMENTS, ACKNOWLEDGEMENT AND COVENANTS

         SECTION 1.1 Amendments to Section 3.2

         (a) Section 3.2 of the LLC Agreement is amended to include a
definition of the "Asset Purchase Agreement" as follows:

                           "Asset Purchase Agreement" means that certain Asset
         Purchase Agreement entered by and between the Company and RMC
         Mid-Atlantic, LLC, a South Carolina limited liability company and an
         Affiliate of Cemex, dated September 1, 2005.

         SECTION 1.2 Amendments to Section 21

         (a) Section 21.1 of the LLC Agreement is amended and restated in its
entirety to read as follows:

                           21.1 Notwithstanding anything in this LLC Agreement
         to the contrary, each of Cemex and RMUSA hereby agrees (and any
         Permitted Transferee of either of the foregoing shall agree) that any
         Damages for which it or any of its Affiliates (the "Indemnifying
         Party") owes the other party (or its Affiliates) or the Company or
         Cemex Southeast LLC (the "Indemnified Party") an indemnification
         obligation under the Contribution Agreement, the Cemex Contribution
         Agreement or the Asset Purchase Agreement shall be paid from any
         distributions that otherwise would be paid by the Company to the
         Indemnifying Party and its Affiliates pursuant to Section 6.1 or
         otherwise, and each party hereby irrevocably waives all rights and
         title it would otherwise have to, and irrevocably instructs the
         Manager to pay to the Indemnified Party, all distributions that
         otherwise would be paid by the Company to the Indemnifying Party and
         its Affiliates under this LLC Agreement, until all such Damages have
         been paid in full to the Indemnified Party. For purposes of this
         Section 21.1, each party acknowledges that to the extent any
         distributions are paid to the Indemnified Party under Section 21.1 of
         the Cemex Southeast LLC Agreement in respect of a particular
         indemnification claim, such payments will also reduce the amount of
         such Damages. In the event of multiple claims, the distributions shall
         be applied against such claims in the order in which the amount of the
         indemnification obligation in respect thereof is finally determined.
         Notwithstanding anything in this LLC Agreement to the contrary, in no
         event shall any amount of damages withheld by the Company under this
         Section 21.1 as a payment of indemnified Damages incurred by the
         Company be treated as (i) EBITDA for purposes of (x) calculating the
         amount of any required distribution (including pursuant to Section
         6.1) or (y) determining the Purchase Price or the Buyout Purchase
         Price, or (ii) available cash for purposes of determining the amount
         of any distribution under Section 9.6.4(a). The parties acknowledge
         and agree that in the event RMC Mid-Atlantic, LLC is no longer an
         Affiliate of Cemex such change in status shall not affect the
         obligations under this Section 21.1 and any Damages for which RMC
         Mid-Atlantic, LLC owes the Company (or its Affiliates) an
         indemnification obligation under the Asset Purchase Agreement shall be
         paid as provided in this Section 21.1 as if RMC Mid-Atlantic, LLC
         remained an Affiliate of Cemex. For purposes of this Section 21, none
         of Cemex, RMUSA or any of their respective Affiliates shall be deemed
         to be Affiliates of the Company or any of its Subsidiaries or Cemex
         Southeast LLC or any of its Subsidiaries.

         (b) The definition of "Net Indemnity Obligation" in Section 21.4 of
the LLC Agreement is amended and restated in its entirety to read as follows:

                           "Net Indemnity Obligations" means, with respect to a
         particular Indemnifying Party as of a particular time, the amount, if
         any, by which (i) the aggregate Damages for which it and its
         Affiliates owes the Indemnified Party and any of its Affiliates an
         indemnification obligation under the Contribution Agreement and the
         Asset Purchase Agreement as of such time exceeds (ii) the aggregate
         Damages for which the other Indemnifying Party (or Member, as the case
         may be) and any of its Affiliates owes the Indemnified Party and any
         of its Affiliates an indemnification obligation under the Contribution
         Agreement and the Asset Purchase Agreement as of such time. For
         purposes of determining the Net Indemnity Obligation, only Damages
         which have been finally determined (whether by agreement of the
         parties or by any final, non-appealable determination of any tribunal
         with jurisdiction) shall be taken into account.

         SECTION 1.3 Amendments to Exhibit A

         (a) The first column of Exhibit A of the LLC Agreement titled "Member
Name and Mailing Address" is amended and restated in its entirety to read as
follows:

                           READY MIX USA, INC.
                           1300 McFarland Blvd NE
                           Tuscaloosa, AL 35406
                           Attn: Scott Phelps
                           Fax: (205) 345-5772

                           CEMEX SOUTHEAST HOLDINGS, LLC
                           840 Gessner, Suite 1400
                           Houston, TX 77024
                           Attn: Leslie White
                           Fax: (713) 722-5110

         SECTION 1.4 Amendments to Exhibit C

         (a) Exhibit C of the LLC Agreement is amended and restated in its
entirety to read as follows:

                           READY MIX USA, INC.
                           1300 McFarland Blvd NE
                           Tuscaloosa, AL 35406


                                  ARTICLE II

                                REPRESENTATIONS

         Each of Company, Cemex and RMUSA hereby represents to the other that
(a) it has full organizational power and authority to execute and deliver this
Amendment and to consummate the transactions contemplated hereby, (b) the
execution and delivery of this Amendment by such party have been duly and
validly authorized by all necessary corporate action on the part of such party
and (c) this Amendment has been duly and validly executed and delivered by such
party and constitutes a valid and binding obligation of such party, enforceable
against such party in accordance with its terms, except that such
enforceability (i) may be limited by bankruptcy, insolvency, moratorium or
other similar laws affecting or relating to the enforcement of creditors'
rights generally and (ii) is subject to general principles of equity and the
discretion of the court before which any proceedings seeking injunctive relief
or specific performance may be brought.


                                  ARTICLE III

                                 MISCELLANEOUS

         SECTION 3.1 Headings. The headings contained in this Amendment are for
reference purposes only and shall not affect in any way the meaning or
interpretation of this Amendment.

         SECTION 3.2 Counterparts. This Amendment may be executed in two or
more counterparts, each of which when executed shall be deemed to be an
original but all of which shall constitute one and the same agreement.

         SECTION 3.3 Governing Law. This Amendment shall be governed, construed
and enforced in accordance with the Laws of the State of Delaware without
giving effect to the principles of conflicts of law thereof.

         SECTION 3.4 No Other Effect on the LLC Agreement. Except as modified
by this Amendment, all of the terms of the LLC Agreement are hereby ratified
and confirmed and shall remain in full force and effect.





         IN WITNESS WHEREOF, Company, Cemex and RMUSA have caused this
Amendment to be signed by their respective officers thereunto duly authorized
as of the date first written above.

                                             READY MIX USA, LLC


                                             By:  Ready Mix USA, Inc.
                                                  Its Manager

                                                  By:  /s/ Marc Bryant Tyson
                                                       -----------------------
                                                       Marc Bryant Tyson
                                                       Its Manager





                                             READY MIX USA, INC.


                                             By: /s/ Marc Bryant Tyson
                                                 -----------------------------
                                                 Marc Bryant Tyson
                                                 Its President





                                             CEMEX SOUTHEAST HOLDINGS LLC


                                             By: /s/ Gilberto Perez
                                                 ---------------------------
                                                 Name:  Gilberto Perez
                                                 Title: President