Exhibit 3.28b

                       CERTIFICATE OF LIMITED PARTNERSHIP
                                       OF
                                 REDI-MIX, L.P.

          The undersigned General Partner, desiring to form a limited
partnership under the provisions of the Texas Revised Limited Partnership (the
"Act"), hereby certifies as follows:

     1. The name of the limited partnership is Redi-Mix, L.P.

     2. The address of the limited partnership's registered office is 1445
MacArthur, Suite 136, Carrollton, Texas 75007. The name of the limited
partnership's registered agent for service of process is John C. Miller. The
address of the registered agent is 1445 MacArthur Suite 136, Carrollton, Texas
75007.

     3. The address of the principal office where records are required to be
kept or made available is 1445 MacArthur, Suite 136, Carrollton, Texas 75007.

     4. The name, mailing address, and street address of the business of the
sole general partner is as follows:



Name:                       Mailing and Street Address
- ----                        --------------------------
                         
REDI-MIX MANAGEMENT, INC.   1445 MacArthur, Suite 136
                            Carrollton, Texas  75007


     5. This certificate of limited partnership shall be effective on the date
of filing with the Secretary of State of the State of Texas.

     6. The limited partnership is being formed pursuant to a plan of conversion
under Section 2.15 of the Act.

     7. The name of the converting entity is Redi-Mix, Inc., a Texas business
corporation. The address of Redi-Mix, Inc. is 1445 MacArthur, Suite 136,
Carrollton, Texas 75007. Its date of incorporation was June 11, 1979, and its
jurisdiction of incorporation is Texas.



          The undersigned affirms, under the penalties of perjury, that this
certificate is executed on the 28th day of April, 1999, and to the best
knowledge and belief of the undersigned, the facts stated in this certificate
are true.

                                        REDI-MIX MANAGEMENT, INC.,
                                        a Texas corporation


                                        By:
                                            ------------------------------------
                                        Name: John C. Miller
                                        Title: Secretary