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                                                                     Exhibit 3.6


                                   BY-LAWS OF
                        ADDISON STRUCTURAL SERVICES, INC.

                                   ARTICLE I.
                                     OFFICES

      The principal offices of the Corporation shall be located in the City of
Albany, State of Georgia. The Corporation may have such other offices, either
within or without the State of Florida, as the Board of Directors may designate
or as the business of the Corporation may require from time to time.

      The registered office of the Corporation, required by the Florida
Corporation laws to be maintained in the State of Florida may be, but need not
be, identical with the principal office in the State of Florida, and the address
of the registered office may be changed from time to time by the Board of
Directors.

                                   ARTICLE II.
                                  SHAREHOLDERS

      Sec. 1. ANNUAL MEETINGS. The annual meeting of the shareholders shall be
held at the principal office of the Corporation on the 2nd Monday in July each
year at 9:00 a.m. The Secretary shall serve personally, or send through the mail
at least ten days before such meeting, a notice thereof addressed to each
shareholder of record at his last known post office address; but at any meeting
at which all shareholders not present have waived notice in writing, the giving
of notice as above required shall be dispensed with.

      Sec. 2. QUORUM.  At all meetings of shareholders it shall be necessary
that stockholders representing in person or by proxy a majority of the
outstanding capital stock shall be present to constitute a quorum.

      Sec. 3. SPECIAL MEETINGS.  Special meetings of shareholders may be
called at any time by the Chairman or by a majority of the directors upon ten
days notice to each shareholder of record, and to be served personally or
sent through the post office addressed to each of such shareholders of record
at his last known post office address; but at any meeting at which all
shareholders shall be present, or of which shareholders not present have
waived notice of the meeting in writing, the giving of notice as above
required shall be dispensed with.

      The Board of Directors shall also, in like manner, call a special meeting
of shareholders whenever and wherever so required in writing by shareholders
representing not less than one-half of the capital stock of the company.
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      Sec. 4. VOTING. At all meetings of shareholders all questions, the manner
of deciding which is not prescribed by statute, shall be determined by a
majority vote of the shareholders present in person or by proxy; provided,
however, that any qualified voter may demand a stock vote, in which case each
shareholder present in person or proxy shall be entitled to cast one vote for
each share of stock owned or represented by him. All voting shall be done by
voice except that a stock vote shall be by ballot. The casting of all votes at
meetings of the shareholders shall be governed by the provisions of the statutes
of Florida thereunto pertaining.

      Sec. 5. ORDER OF BUSINESS.  The order of business at all meetings of
the shareholders shall be as follows:

            1.    Roll Call

            2.    Proof of notice of meeting or waiver of notice

            3.    Reading of minutes of preceding meeting

            4.    Report of officers

            5.    Reports of committees

            6.    Election of inspectors of election

            7.    Unfinished business

            8.    New business

      Sec. 6. INFORMAL ACTION BY SHAREHOLDERS.  Any action required or
permitted to be taken at a meeting of the shareholders may be taken without a
meeting if a consent in writing, setting forth the action so taken shall be
signed by the holders of outstanding stock having not less than the minimum
number of votes that would be necessary to authorize or take such action at a
meeting at which all shares entitled to vote thereon were present and voted.

                                  ARTICLE III.
                                    DIRECTORS

      Sec. l. NUMBER.  The affairs and business of this Corporation shall be
managed by a Board of Directors consisting of 5 person(s) who need not be
shareholder(s).

      Sec. 2. HOW ELECTED.  At the annual meeting of shareholders, the
person(s) receiving a plurality of the votes cast shall be directors and
shall constitute the Board of Directors for the coming year.

      Sec. 3. TERM OF OFFICE.  The term of office of each of the directors
shall be one year, and thereafter until his successor has been elected and
has qualified.

      Sec. 4. DUTIES OF DIRECTORS. The Board of Directors shall have the control
and general management of the affairs and business of the Corporation, and
exercise all the powers, rights, and privileges permitted to be exercised by
directors of Corporations for profit under the statutes of the State of Florida
thereunto pertaining. Such directors shall in all cases act as a board,


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regularly convened by a majority, and they may adopt such rules and regulations
for the conduct of their meetings and the management of the Corporation as they
may deem proper, not inconsistent with these By-laws and the laws of the State
of Florida.

      Sec. 5. DIRECTORS' MEETINGS.  An annual meeting of the Board of
Directors shall be held immediately following the annual meeting of the
shareholders.  Special meetings of the Board of Directors may be called by
the Chairman at any time, and must be called by the President or Secretary
upon the written request of two directors.  The directors shall meet at such
place and time as may be designated in the notice of such meeting.

      Sec. 6. NOTICE OF MEETINGS. Notice of meetings other than the annual
meeting shall be given by service upon each director by mail or in person at
least two days before the date therein designated for such meeting, including
the day of mailing of written or printed notice thereof, specifying the time and
place of such meeting. At any meeting at which every member of the Board of
Directors shall be present, or to the holding of which an absent director has
consented in writing, although held without notice, any business may be
transacted which might have been transacted if the meeting had been duly called.

      Sec. 7. QUORUM.  At any meeting of the directors, majority of the board
shall constitute a quorum for the transaction of business, but in the event
of a quorum not being present, a lesser number may adjourn the meeting to
some future time, but not more than five days later.

      Sec. 8. VOTING.  At all meetings of the Board of Directors, each
director is to have one vote.

      Sec. 9. VACANCIES. Whenever any vacancies shall occur in the Board of
Directors by death, resignation, removal or otherwise, the same shall be filled
without undue delay by a majority vote of the remaining members of the Board of
Directors. Such election shall be held within thirty days after the occurrence
of such vacancy. The person so chosen shall hold office until the next annual
meeting of the shareholders, or until his successor shall have been chosen at a
special meeting of the shareholders or by informal action of the shareholders.

      Sec. 10.    REMOVAL OF DIRECTORS.  Any one or more of the directors may
be removed with or without cause at any time by a vote of the shareholders
holding a majority of the outstanding stock at any meeting of the
shareholders or by informal action of the shareholders pursuant to Article
II, Section 6 of these By-laws.

      Sec. 11.    ACTION WITHOUT A MEETING.  Any action required or permitted
to be taken by the Board of Directors at a meeting may be taken without a
meeting if a consent in writing setting forth the action so taken, shall be
signed by all of the directors.


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                                   ARTICLE IV.
                                    OFFICERS

      Sec. 1. NUMBER.  The officers of the Corporation shall be:

                  1.    Chairman

                  2.    President

                  3.    Vice President

                  4.    Secretary

                  5.    Treasurer

      Sec. 2. ELECTION.  All officers of the Corporation shall be elected
annually by the Board of Directors at its meeting held immediately after the
annual meeting of shareholders and shall hold office for the term of one
year, or until their successors are duly elected and have qualified.

      Sec. 3. DUTIES OF OFFICERS.  The duties and powers of the officers of
the Corporation shall be as follows:

                                    CHAIRMAN

      The Chairman shall preside at all meetings of the Board of Directors and
of the shareholders. He shall cause to be called regular and special meetings of
the shareholders and directors in accordance with these By-laws.

      He shall appoint and remove, employ and discharge, and fix the
compensation of all servants, agents, and employees of the Corporation, other
than the duly elected officers, subject to the approval of the Board of
Directors.

      He shall sign and make all contracts and agreements in the name of the
Corporation and see that they are properly carried out.

      He shall see that the books, reports, statements and certificates required
by the statutes of Florida are properly kept, made and filed according to law.

      He shall exercise all the rights and privileges and perform all the duties
usually pertaining to the office of Chairman of a Corporation for profit.

                                    PRESIDENT

      During the absence or inability of the Chairman to render and perform his
duties or to exercise his powers, the same shall be performed and exercised by
the President; and when so acting, he shall have all the powers and be subject
to all the responsibilities hereby given to or imposed upon the Chairman.


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                                    SECRETARY

      The Secretary shall keep the minutes of the meetings of the Board of
Directors and shareholders in an appropriate book or books.

      He shall serve all notices of the Corporation.

      He shall be a custodian of the records and of the seal, and affix the
latter when required.

      He shall keep the stock book so as to show at all times the amount of the
outstanding capital stock, the manner and the time the same was paid in, and the
names and post office addresses of the owners thereof.

      He shall, with the Chairman, sign all certificates of stock.

      He shall perform all the duties usually incident to the office of
Secretary.

                                    TREASURER

      The Treasurer shall have the care and custody and be responsible for all
the funds and securities of the Corporation, and deposit all such funds in the
name of the Corporation in such bank or banks, or otherwise as the Board of
Directors may designate.

      He shall keep, or cause to be kept at the office of the Corporation,
correct books of account of all of its business and transactions.

      He shall do and perform all the duties pertaining to the office of
Treasurer.

      Sec. 4. ALL VACANCIES - HOW FILLED.  All vacancies in any office shall
be filled by the Board of Directors.

      Sec. 5. COMPENSATION OF OFFICERS.  The Board of Directors shall
determine the salary or compensation to be received by the officers.

      Sec. 6. REMOVAL OF OFFICERS.  The Board of Directors may remove any
officer by a majority vote at any time with or without cause.

                                   ARTICLE V.
                                      SEAL

      Sec. I. SEAL.  The seal of the Corporation shall be as follows:


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                                   ARTICLE VI.
                              CERTIFICATES OF STOCK

      Sec. l. DESCRIPTION OF STOCK CERTIFICATES. The certificates of stock shall
be numbered and registered in the order in which they are issued. They shall be
bound in a book and shall be issued in consecutive order therefrom, and in the
margin thereof shall be entered the name of the person owning the shares therein
represented, with the number of shares and the date thereof. Such certificates
shall exhibit the holder's name and number of shares. They shall be signed by
the Chairman or President and countersigned by the Secretary and sealed with the
seal of the Corporation.

      Sec. 2. TRANSFER OF STOCK. The stock of the Corporation shall be assigned
and transferable on the books of the Corporation only by the person in whose
name it appears on said books or his legal representatives. In case of transfer
by attorney, the power of attorney duly executed and acknowledged, shall be
deposited with the Secretary. In all cases of transfer, the former certificate
must be surrendered and called before a new certificate may be issued. No
transfer shall be made upon the books of the Corporation within ten days next
proceeding the next annual meeting of the shareholders. Any taxes in connection
with the transfer of any such shares shall be paid by the transferor or the
transferee of said stock before said assignment and transfer shall be made on
the books of the Corporation.

                                  ARTICLE VII.
                                    DIVIDENDS

      Sec. 1. WHEN DECLARED.  The Board of Directors may from time to time
declare and the Corporation may pay dividends on its outstanding shares in
the manner and upon the terms and conditions provided by law and the articles
of incorporation.

                                  ARTICLE VIII.
                               BILLS, NOTES, ETC.

      Sec. 1. HOW MADE. All bills payable, notes, checks or other negotiable
instruments of the Corporation shall be made in the name of the Corporation, and
shall be signed by such officer or officers as the Board of Directors shall from
time to time direct. No officer or agent of the Corporation, either singly or
jointly with others, shall have the power to make any bill payable, note, check,
draft or warrant or other negotiable instrument, or endorse the same in the name
of the Corporation or contract or cause to be contracted any debt or liability
in the name or on behalf of the Corporation, except as herein expressly
prescribed and provided.


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                                   ARTICLE IX.
                                   AMENDMENTS

      Sec. 1. HOW AMENDED.  These By-laws may be altered, amended, repealed
or added to by the affirmative vote of the stockholders representing a
majority of the outstanding capital stock at any meeting of the stockholders
called for such purposes or by informal motion of the shareholders pursuant
to Article 2, Section 6 of these By-laws.

                                   ARTICLE X.
                                 INDEMNIFICATION

      Sec. 1. ACTIONS NOT BY OR IN THE RIGHT OF THE COMPANY.  This
Corporation shall indemnify any person who was or is a party to any
proceeding (other than an action by, or in the Corporation's right), by
reason of the fact that he is or was a director, officer, employee, or agent
of the Corporation, or is or was serving at the request of the Corporation as
a director, officer, employee or agent of another Corporation, partnership,
joint venture, trust or other enterprise, against liability incurred in
connection with such proceeding, including any appeal thereof, if he acted in
good faith and in a manner he reasonably believed to be in, or not opposed
to, the best interests of the Corporation, and with respect to any criminal
action or proceeding, had no reasonable cause to believe his conduct was
unlawful.

      Sec. 2. ACTIONS BY OR IN THE RIGHT OF THE COMPANY. The Corporation shall
indemnify any person who was or is a party to any proceeding by, or in the
Corporation's right, to procure a judgment in its favor because such person is
or was a corporate, director, officer, employee or agent or was serving at the
Corporation's request as a director, officer, employee or agent of another
Corporation, partnership, joint venture, trust or other enterprise, against
expenses and amounts paid in settlement which, in the Board of Directors'
judgment, do not exceed the estimated expense of litigating the proceeding to
conclusion. Such indemnification shall not exceed the amounts actually and
reasonably incurred in connection with the defense of such proceeding and any
appeal thereof. Such indemnification shall be authorized if such person acted in
good faith and in a manner he reasonably believed to be in, or not opposed to,
the best interests of the Corporation, except that no indemnification shall be
made under this Section 2 in respect of any claim, issue, or matter as to which
such person shall have been adjudged to be liable unless, and only to the extent
that, the court in which such proceeding was brought or any other court of
competent jurisdiction, shall determine upon application that despite the
adjudication of liability but in view of all circumstances of the case, such
person is fairly and reasonably entitled to indemnity for such expenses which
such court shall deem proper.

      Sec. 3. INDEMNIFICATION WHERE OFFICER OR DIRECTOR SUCCESSFULLY DEFENDS
ACTIONS.  To the extent that a director, officer, employee, or agent of the
Corporation has been successful on the merits or otherwise in defense of any
proceeding referred to in Section 1 or Section 2, or in defense of any claim,
issue, or matter therein, he shall be indemnified against


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expenses (including, but not limited to, attorneys' fees) actually and
reasonably incurred by him in connection therewith.

      Sec. 4. STANDARDS REQUIRED PRIOR TO INDEMNIFICATION.  Except as
provided in Section 3 hereof and except as may be ordered by a court, any
indemnification under Section 1 or Section 2, shall be made by the
Corporation only as authorized in the specific case upon a determination that
indemnification of the director, officer, employee, or agent is proper in the
circumstances because he has met the applicable standard of conduct as set
forth in Section 1 or Section 2.  Such determination shall be made:

              (a) By the Board of Directors by a majority vote of a quorum
              consisting of directors who were not parties to such proceeding;

              (b) If such a quorum is not obtainable or, even if obtainable, by
              majority vote of a committee duly designated by the Board of
              Directors (in which directors who are parties may participate)
              consisting solely of two or more directors not at the time parties
              to the proceeding;

              (c) By independent legal counsel;

                  1.    Selected by the Board of Directors prescribed in
              paragraph (a) or the committee prescribed in paragraph (b); or

                  2. If a quorum of the directors cannot be obtained for
              subparagraph (1) and the committee cannot be designated under
              paragraph (b), selected by majority vote of the full Board of
              Directors (in which directors who are parties may participate); or

              (d) By the shareholders by a majority vote of a quorum consisting
              of shareholders who were not parties to such proceeding or, if no
              such quorum is obtainable by a majority vote of shareholders who
              were not parties to such proceeding.

      Sec. 5. EVALUATION OF EXPENSE REASONABLENESS AND INDEMNIFICATION
AUTHORIZATION.  Evaluation of the reasonableness of expenses and
authorization of indemnification shall be made in the same manner as the
determination that indemnification is permissible.  However, if the
determination of permissibility is made by independent legal counsel, persons
specified by Section (4)(c) shall evaluate the reasonableness of expenses and
may authorize indemnification.

      Sec. 6. ADVANCE OF EXPENSES. Expenses incurred by an officer or director
in defending a civil or criminal proceeding may be paid by the Corporation in
advance of the final disposition of such proceeding upon receipt of an
undertaking by or on behalf of such director or


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officer to repay such amount if he is ultimately found not to be entitled to
indemnification by the Corporation pursuant to this article. Expenses incurred
by other employees and agents may be paid in advance upon such terms or
conditions that the Board of Directors deems appropriate.

      Sec. 7. CONTINUATION OF INDEMNIFICATION.  These indemnification
provisions shall continue in effect (unless otherwise provided when
authorized or ratified) for persons who have ceased to be a director,
officer, employee or agent and shall additionally apply for the benefit of
the heirs, executors and administrators of such persons (unless otherwise
provided when authorized or ratified).

      Sec. 8. INSURANCE.  The Corporation may purchase and maintain insurance
on behalf of any person who is or was a director, officer, employee or agent
of the Corporation or is or was serving at the request of the Corporation as
a director, officer, employee or agent of another corporation, partnership,
joint venture, trust, or other enterprise against any liability asserted
against him and incurred by him in any such capacity or arising out of his
status as such, whether or not the Corporation would have the power to
indemnify him against such liability under the provisions of this section.

      Sec. 9. NON-EXCLUSIVITY. The indemnification and advancement of expenses
provided pursuant to this article are not exclusive and the Corporation may make
any other or further indemnification or advancement of expenses of any of its
directors, officers, employees, or agents, under any bylaw, agreement, vote of
shareholders or disinterested directors, or otherwise, both as to action in his
official capacity and as to action in another capacity while holding such
office.

      Sec. 10.    NOTICE TO SHAREHOLDERS.  If any expenses or other amounts
are paid by way of indemnification otherwise than by court order or action by
the shareholders or by an insurance carrier pursuant to insurance maintained
by the Corporation, the Corporation shall, not later than the time of
delivery to shareholders of written notice of the next annual meeting of
shareholders, unless such meeting is held within three (3) months from the
date of such payment, and, in any event, within fifteen (15) months from the
date of such payment, deliver either personally or by mail to each
shareholder of record at the time entitled to vote for the election of
directors, a statement specifying the persons paid, the amounts paid, and the
nature and status at the time of such payment of the litigation or threatened
litigation.

      Sec. 11.    PRECLUSION OF INDEMNIFICATION OR EXPENSE ADVANCEMENT.
Notwithstanding any other provision of this Article, indemnification or
advancement of expenses shall not be made to or on behalf of any director,
officer, employee, or agent if a judgment or other final adjudication
establishes that his actions, or omissions to act, were material to the cause
of action so adjudicated and constitute:

              a. A violation of the criminal law, unless the director, officer,
      employee or agent had reasonable cause to believe his conduct was lawful
      or had no reasonable cause to believe his conduct was unlawful;


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              b. A transaction from which the director, officer, employee or
      agent derived an improper personal benefit; or

              c. Willful misconduct or a conscious disregard for the best
      interests of the Corporation in a proceeding by or in the right of the
      Corporation to procure a judgment in its favor or in a proceeding by or in
      the right of a shareholder.


                                          /s/  E. C. Addison
                                          --------------------------------
                                          E. C. Addison


                                          /s/  Paul Macomber
                                          --------------------------------
                                          Paul Macomber


                                          /s/  T. M. Phagans
                                          --------------------------------
                                          T. M. Phagans


                                          /s/  Glen Davis
                                          --------------------------------
                                          Glen Davis


                                          /s/  Sam Mahdavi
                                          --------------------------------
                                          Sam Mahdavi


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