ST8201-CN 881017 . CHANGE ORDER .r"'
i t t' , . ,~': ' .. ,' .
( ns ruc tons on reverse side) No
PROJECT' Denton Tap Road Improvements /~/D~"I?~ OFffl'~s/~CE'111'I~'[;'} !'"'*"~/"'"~ '.-:, i.: ~ .:'~
' from Belt Line Road.to Sandy ~alm-~ur' 7/)11:i!,!:',i .... ,. ,., ~.,,,-o
OWNER: City of Coppell -~'~_~ ~--~jlt_~/* [t[3'1 :.,"
p.o Box 478 -~~.~ /
(Name, .__i_, ........... ~'~'~ :" ' :' "' ,~ a ,~ ~ 1 ~ ~ ~
Address) ~uppu~z, ~exas /~ux~ ':' ~ }, '~ [.'~F'~F<F;[2~.~.
CONTRA~OR: L.H. Lacy Co. OWNER's Project No.
P.O. BOX 541297
Dallas, Texas 75354 ENGINEER: Gi~, Inc.
17103 ~eston Rd., Suite
CONTRACT FOR: · ~nton Tap Road Improvements L.B. 118
from Belt Line Rd. to Sandy Lake Rd. Dallas, T~xas 75248 3-378
ENGINEER's Project No,. '
You are directed to make the following changes in the Contract Documcnls.
Description: Substitute Portland. Cement at $50.00/TON for Lime Slurry, Ty. A, 5%, 22.5#/8Y
at $61.00/TON (Pay Item 264); and Cement Treatment, mat. in place, for Lime Treatment,
mat. in place at the same unit prices (Pay Item 260).
Purpose of Change Order: TO achieve an estimated reduction in Estimated Contract Amount of
$7,624.10, while providing a constructed project which will be equal to that which was
originally specified.
Attachments: (List documentssupportingchange) 1. L.H. Lacy Co. letter of October 8, 1988 to Ginn, Inc.
2. John It. Itavnes ,~_Associates, Inc. October 17, 1988
letter to Ginn, Inc.
CHANGE IN CONTRACT PRICE: CIlANGE IN CONTRACT TIME:
Odginal Contract Price Original Contract 'rime
$. 3,362,580.00 365
days ur dull:
Previous Change Orders No~ N/A to No. N/A Net change fr?m prcvious Change Orders
$ N/A 0
days
Contract Price prior to this Change Order Contract Time Prior Io this Change Order
3,362,580.00 365
$.
· days m d~lc
Net Increase (decrease) of this Change Order Net Increase (decrease) of this Change Order
$. approx. ($7'624.10) 0
days
Contract Price with all approved Change Orders Contract Time wilh all approved Change Orders
3,354,955.90
$
days or dale
· , --_/ , '-,"-'-- .' ' [. ,
E.ICDC No. 1910-8-B (1983 Edition)
I
Prepared by thc Engineers' Joinl Contract Documents Conmlill¢¢ and endorsed by Thc Associaled General Conlruclors of America.
JOHN H. HAYNES & ASSOCIATES, INOOI=IPOIZlATE[:)
Geotechnical Engineers
November 4, 1988
L. ii. Lacy Company
10888 Shady Trail
P. O. Box 541297
Dallas, Texas 75354-1297
Attention: Mr. David M. Snyder, P.E.
Re: Cement Stabilization Tests
Denton Tap Road Improvements
Coppell, Texas
Job No. 3198(b)'
Report No. 18
Gentlemen:
As requested, we have checked the roadway subgradc along Ibc refcrcnccd
alignment to locate representative clay samples with high Liquid Limits in Ihe
range of about 48 to 56. Two samples were obtained and lesled to evaluate their P!
reduction wilb the use of cement. The results of these sludiea arc shown on Plate
No. I. It was found that thc dark gray clay sample baying an LL of 47.5 was
effectively stabilized with 5% cement addition having a reduction in PI lo 10.9.
llowcver, in the case of the sample with an LL of 55.8, 5% cement only reduced thc
P! lo 13.3 whereas 7% cement reduced the PI to 10.7. With Ibc exception of this
latter sample obtained at Station 91+00, all other areas of subgradc checked
appeared to have lower plasticity than thc other sample tested.
Therefore, it is our opinion that 5% cement can be substituted for 5% lime as
requested by th, e contractor in all areas with equal reduction in PI to bclow 12 with
Ibc exception 'of the area around Station 91+00. In this area (and probably up and
down slation maybe 100'), it is recommended that the cement factor bc raiscd to 7%
for adequalc P! reduction. The actual extent of the arca underlain by the higher
plastic clay (identified as light gray, dark gray and lan Cit. clay) should bc
idenlified on the ground by our engineering Icchnician and marked for thc
higher concentration if cement is substituted for the specified lime material.
The compaction specification that L. lt. Lacy suggested to usc for the cement
stabilization' work (COG Spec Item 4.9) indicates thc usc of thc TllD l13-E method. In
order to reduce costs, it is our opinion that a substitution could be made whcreby
the Modified Proctor Method (ASTM D-1557) could bc used and a minimum
requirement of 95% Modified compaction is required. It is believed Ihat very little.
difference in densily will occur if this substitution is made and 95% compaction is
still required.
2424 Stutz IZ)rive · I~.O. Box .~i~481 · IZ)allee, Texas 75235 · (214) .~150-~600
JOHN H. HAYNES & ASSOCIATES. INC,
Geotechnical Engineers
Oinn, Inc. 2 November 4, 1988
If wc can bc of further help, please let us know.
Yours very truly,
JOIIN Il.IIAYNES & ASSOCIATES, INC.
lllll/jeh
(2 copies submilled)
cc: Mr. Rnndy Fleming (1 copy)
Ginn, Inc.
Denton Tap Road Improvements
Coppel 1, Texas
Atterber9 Limit Tests on Subgrade Soils
% Liquid P1 astic Plastici
Stati on Descri ptiok- Cement Limi t(%) Limi t(%), Index (PI
91+00, Rt. Light gray, dark - 55.8 18.9 36.9
gray and tan clay
with trace sand and
gravel
5 43 5 30.2 13.3
'
7 43.7 33.0 10.7
140+00, Rt. Dark gray clay with - 47.5 16.4 31.1
trace sand
5 41.3 30.4 10.9
JOHN H. HAYNES & ASSOCIATES, INCOFIPOFIA
Geotechnical Engineers
October 17, 1988
Oinn, Inc.
17103 Preston Road, Suite 100, LB 118
Dallas, Texas 75248
Attention: Mr. John Karlsruher, P.E.
Re: Cemcnt Stabilization Subslitution
Denton Tap Road hnprovemcnls
Coppell, Texas
.lob No. 3198(b)
Ocntlcmcn:
In accordance with your letter request of October 12, 1988, we have reviewed L.
H. Lacy's request for a substitution of 5% cement f. or the specified 5% lime for
subgrade stabilization on this project with the change in procedural specifications to
thc North Central Council of Government Standard Specification Item 4.9.
Wc bclie~,e this substitution would be acceptable provided that it is
demonstrated that 5% cement will reduce thc PI of all thc subgradc soils along thc
project lo not greater than 12. In our original geolechnical reports, we identified
some number of plastic clays along the alignment which had Liquid Limits of 50 to 58
and Pl's of 27 to 34. In order to prove Ihat 5% cement is adequate, we suggest that thc
subgradc hc checked and at least two samples of 'untrealcd clay be obtained for
laboratory tests.that have a Liquid Limit greater than 50. The untreated PI' of these
clays should be on the order of 30 to 35 and this should be proved by laboratory test.
These plastic' clay samples should then be treated wilh 5% cement and it should be
demonstrated that this is sufficient to reduce thc PI lo not more than 12. If this is not
possible, additional cement should be added until this PI reduction is achieved. Ali
areas should then be uniformly treated with at least 5% cement or more if it is found
that a greater cement factor is required to stabilize these plastic clay soils.
It 'should be pointed out that COG Spec. Item 4.9 requires compaction, to ~bc '
conti'olled by Test Method THD l I3-E. The cost of this 24' hour Mbdified Proctor re'st is
:~424 Stutz Drive ~ P.O. Box 354B1 ·Oallas. Texas 75235 · (214) 350-5600
JOHN H. HAYNES & A,~_~OCIATES. INC.
Geotechnical Engineers
Oinn, Inc. 2 August 23, 1988
higher than the 24 hour Standard Proctor test ($200 vs. $140) so a slight difference in
cost will be incurred.
If you have any questions concerning this report, please let us know.
Yours very t'ruly,
JOIIN I[. IIAYNES & ASSOCIATES, INC.
l Hll/jeh
UC I UI-.~E.I~ ~., 1 ~-?EI8 ' r
I~i 1NN., ],NC.
I / 1 C).Z~ PRES'I UN
SUI'IIg l(..)U., L..U-118
DALLAS., I X 75'-'."~ILCJ '
~: tJENI'UN I/-~P ROAD II¥1F'RLJVEMEN'T PROOEC'I'S FF(OM BELT LINE '1'0 I)ENI"ON CREEK
ATTN: JOHN C. KARLSRUHER., P.E.
JOHN ~
THE L. H. LACY CO. WOULD LIKE TD FORMALIZE IT'S REQUEST FOR THE FOLLDNING
ALTERNATIVE METHOD OF SUBGRAI)E B'rABILIZA'rlON ON BOTH OF THE ~BOVE REF'ERRENCED
PRO,] EC TS:
SANDY LAKE TO DENTON CREEK
PROJI~CI' (579)
1)' ITEM 2~4 - LIME~ 168 TON TO ITEM.264 - CEMENT~ 1~8 TON
lA) ITEM 2&4. 1 - LIME (9")~ 50~ TON TO ITEM 2&z~. 1 .- CEMENT~ 504 ]'ON
~ .
BELT LINE TO SANDY LAKE PROOECT '(578) :'
1) ITEM 2~4 -- LIM~ 695.1 TON 'FO ITEM 2~4 - CEMENT, ~95.1 TON
THE ALTEFCNATE METHOD AND SUBSEQUENT PRICE REDUCTION ARE PFREDICATFD ON TH~
FOLLOWING:
l) ALL WORK 'TO BE DONE IN ACCORDANCE WITH THE ATTACHED NORTH TEXAS COUNCIL
OF GOVERNMENT STANDARD SPECIFICATIONS FOR PUBLIC ~ORKS CONSTI~UC'rlON.
(ITEM 4.9)
2) A ONE TO ONE (i TO 1) SUBSTITUTION OF CEMENT FOR LIME (AS R~FLEC'I'ED
ABOVE ),
THE L. H. LACY COMPANY PROPOSES THE FOLLOWING PRICE REDUCTIONS IN CONSID-
ERATION OF' THE PROPOSAl.. AS IT IS S'I"ATED 1N THIS LETTER., ANY CHANGE IN FIETH[}D
OR QUANTITIES FROM THOSE PROPOSED WILL REQLJIRE A RESPONSE FROM L. H. LAF,'Y
L. H. Lacy Company ' 10888 Shady Trail
General Con tractors ~-J' "'~"'"~-~'-~"~~,,.,,_,~e~-- ........ P.O. Box 541297
214/357'0146 "Qualily Conslruction Ior over 65 Years" Dallas, Texas 75354-1297
ITEM 26q - C:[:'.I'IEN"f., 161~j 'I"i3N "~ ~;50. (')0/TON (F'IFTY D[IL. Lt~F~:S PEI~: 'I"0N)
ITEM 2&4. I. - I:.'Ei'II[:.N'I" (~)"): :'-"'0,1 '¥'l:llq ;~) '$50,Ol'~/l'UN (I":IF:'I'Y [)[)l..Ll.t['~Ci I:~1'_::1.'(]'ON)
1 ) :1' 'rFM 26,~ -- £:E".I'IEN"I"., /~ ~/..:.. ! '[13N :~) .I;~.';0. OLi/TON · ( F ! F:"I'Y DOLLI.~F¢S r-.Et{ TON)
Nb.~ I'::[:1[:~: THE I'rY OF COF~P[:'LI. IN GUPPL¥11q~
Pl:¢OJ El: T
~::F, IC: I:)N[:: (1) t.':[)F'Y ['.IF Ni3i~:'I'I.I 'I'EXt.~S (:OIJl',ll::]L I3F I.!;I.:)VEF"d',II'IENT
L:C: t~ L')l'q
F' l Lli': .310 ' [::I3i~I:'qi:.'?)I)ONI3ENC;E: ,
ITEM 4.5 ~'~ 263
tance by the ows~:R. Repairs are to be made in a manner which shall
insure restoration of a uniform surface. Durability of the part required
shall be measured in its final position and the volume computed in cubic
yards (Ms) by the method of average end area.
Soil-asphalt course shall be measured by the square yard (M~) of sm'-
'' --' face area of completed and accepted work based on the width of the
soil-a~phait course as shown on the plans, or as established by the
owN~.R. Asphaltic material of the type and grade shown on the plans
shall be measured in gallons (liters) at the applied temperature at the
point of application on the read.
Work performed and materials furnished as prescribed and measured
by this item shall be paid for at the unit prices bid for soil-asphalt
course and additional soil, which prices shall be full compensation for
~-~' cleaning the roadbed or the surface of the previously completed base
course; for furnishing all materials; for .loosening excavating, loading,'
hauling and delivering additional soil on the road; for loosening, mixing
and pulverizing of the soil; for shaping, sprinkling and compacting the
subgrade; for all processing, mixing, drying, incorporation of asphaltie
material, aerating and drying, spreading, sprinkling, shaping, eompaet-
v lng, and finishing;, for maintaining under traffic; and for all manipula-
tions, labor, equipment, fuels, tools and incidentals necessary to com-
plete the work except as hereinafter provided.
Asphaltic material measured as provided in this item shall be paid for
at the unit price bid for asphaltic material, which price shall be full
compensation for furnishing the material; for all freight involved; for all
~ unloading, storing, heating, hauling and applying on the road; and for
all labor, equipment, fuels, tools and incidentals necessary to complete
work.
ITEM 4.9. PORTLAND CEMENT MODIFICATION OF SUBGRADE SOILS
4.9.1. DESCRIPTION: This item shall consist of the treating the sub-
grade soils by pulverizing, addition of portland cement and water,
mixing and compacting the mixture to the required density. This item
applies to natural ground or embankment encountered in the con-
strnction. The cement-modified soil layer shail be constructed as
specified herein and in conformity with the typical sections, lines and
grades as shown on the plans or as established by the OWNER.
4.9.2. MATERIALS:
(a) Portland Cement. Cement shall conform to the requirements of
Item 2.2.1., "Cement."
(b) Water. Water shall conform to the requirements of Item 2.2.4.,
"Water."
(c) Soil. The soil shall consist of approved soil, free from vegetation
or other objectionable matter. It may be either the material encountered
in the existing section, material secured from approved sources shown
AUGUST 1867
on the plans or as designated by the owNeR, or a combination of existing
and additional soil from approved sources, as shown on the plans, or as
directed by the
4.g.3. EQUIPMI/NT: All equipment necessary to properly prosecute,
perform and complete the work within the contract time, shall be on the
project and shall be approved by the owH~a as to type and condition be- ~-~
fore the comb'.Ac-rna shall be permitted to begin construction operations
on which the equipment ia to be used.
The cement-medified soil layer may be constructed with any machine
or combination of machines and auxiliary equipment that shall produce
the results meeting the requirements for soil pulverization, cement ap-
plication, water application, mixing, incorporation of mater/als, compac-
tion, and finishing as specified herein. The COSTRACTOa shall at all times
provide sufficient equipment to enable continuous performance of the~
work and its completion in the required number of working days.
4.9.4. ¢ONSTRtlCTION METHODS:
(a) General. The pr/mary requirement of this specification ia to
secure a complete course of treated subgrade material containing a
uniform portland cement mixture, free from loose or segregated areas,
of uniform density and moisture content, well bound and compacted for
its full depth with a smooth surface suitable for placing additional sub*
base, base or surface courses. It shall be the responsibility of the
CONTKACTOR to regulate the sequence of his work to process a sufficient
quantity of material so as to provide full depth as shown on plans, to use
the proper amount of portland cement, maintain the work and to rework
the courses as necessary to meet the foregoing requirements.
Before other construction operations are begun, the roadbed shall
be graded and shaped as required to construct the portland cement
modified subgrade layer in conformance with the lines, grades, thickness
and typical cross sections shown on the plans. Unsuitable soil or material
shall be removed and replaced with acceptable soil. The subgrade shall
" be firm and able to support without displacement the construction equip-
ment and the compaction hereinafter specified. So~ or yielding subgrade
shall be corrected and made stable before construction proceeds.
*----- ~-_ (b) Application of Cement. Portland cement shall be spread uni-
formly by an approved dry or slurry method on the soil at the rate
specified on the plans or as determined by preliminary laboratory tests.
If a bulk cement spreader is used, it shall be positioned by string lines or
other approved methed during spreading to insure a uniform distribu-
tion of cement. Cemen.t. shall be applied only to such an area that all the
Operations can be C0nti'nuOns ~nd ¢omoleted tn one ops. ration. -- .:
The percentaze of moisture in the subgrade soil at the time of
comen~ application shall not' exceed the quantit_v .that Rh~ll ~permit,
~hi[orm and intimate mixture of soil and cement dU~ng ~r~-~uix/ne ope~
itionsLand it shall not exceed tire specified ontlmum moisture cont~-nt '-.~/
four_the soil and cement mixture.
.. No equipment, except that t*~sed in the spreading and mixing, shall
be allowed to pass over the freshly spread cement until it ia mixed with
the soil.
(c) Mixing and Processing. The mixing procedure shall be the same
for "Dry Placing" or "Slurry Placing" as described herein. The material
and cement shall be thoroughly mixed by approved road mixers or other
approved equipment and the mixing shall continue until, in the opinion of
the Engineer, a homogeneous, friable mixture of material and cement i,
obtained, free from all clods or lumps. Materials containing plastic clays
or other material which will not readily mix with cement shall be mixed
as thoroughly as possible at the time of the cement application and
brought to the proper moisture content. The material shall be kept moist
as directed by the Engineer. r
The cement-soil mixture shall meet the following gradation require-
meats when tested dry by laboratory ,ieves:
Minimum Passing 1' Sieve ........................... 100%
Minimum Passing ',~' Sieve ................. , ........ '/0%
Minimum Passing No. 4 Sieve ............. :;. ....... 4595
(d) Compaction. Compaction shall begin immediately after final mix-
lng. The material shall be compacted to 95% of the maximum density, as
established, and in accordance with Test Method Tex II3-E. It shall be
aerated or wetted as necessary to provide optimum moisture. Moisture
toler'.,nces shall be as described below.
Prior to the beginning of compaction, the mixture shall be in a loose
condition for its full depth. Compaction shall begin at the bottom
and shall continue until the entire depth of the mixture is uniformly
compacted.
Description Density, Percent Moisture, Percent
For cetnent treated Not less than 95, Within 2.5 of
subgrade that will except when shown optimum unless
receive subsequent otherwise on the otherwise shown
courses, plans, on the pi,as.
In-PI,co Density tests shall be as outlined in Test Method Tex lI4-E
or Test Method Tex I IS.E. In-Place Density tests shall be performed at
the rate of one per 300 linear feet of paving for two (2) lanes. Tho suits-
bility of the stabilization shall be confirmed by Atterberg Limit testing
at the rate of one test per 2,500 cubie yards of processed material.
In addition to the requirements specified for density, the full depth
of the material shown on the plans shall be compacted to the extent
necessary to remain firm and stable under construction equipment.
After each section is completed, tests as nscessary will be made by the
Engineer. If the material fails to meet the density requirements, it shall
be reworked as necessary to meet these requirements. Throughout this .:
entire operation the shape of the course shall be maintained by bi"ding, -.
and the surface upon completion shall be smooth and in conformity with
the typical section shown on the plans and .to the established lines and
grades. Should the material due to any reason or cause, lose the stabil-
ity, density and finish before the next course is placed or the work is
accepted, it shall be recompacted and refinished at the sole expense of
the CONTRACTOR.
(e) Finishing and Preparation for Surfacing. After the final layer or
course of the cement-modified subgrade has been compacted, it shall be
brought to the required lines and grades in accordance with the typical
sections. The completed section shall then be finished by rolling as di*
rected with a pneumatic tire or other suitable roller sufficiently light to
prevent hair cracking. Preparation t'or final surfacing may begin im-
mediately.
4.9.5. MAINTENANCE: The cowraAcroa shall be required, within the
limits of his contract, to maintain the cement-modified soil in good condi-
tion from the time he first starts work until ali work shall have been
completed. Maintenance shall include immediate repairs of any defect
that may occur after the cement is applied. Such maintenance work shall
be done by the CONTaACTOR at his own expense and repeated as Often as
necessary to kee!) the area continuously intact. Repairs are to be made
in such a manner as to insure restoration of a uniform surface for the full
depth of treatment. Any low area shall be remedied by replacing the
material for the full depth of treatment rather than adding a thin layer of
stabilized material to the completed work.
4.9.6. MEA$OREMKNT AND PAYMFNT: This work shall be measured
by the square yard (M") of completed and accepted cement-modified
soil. Measurement for cement shall be by the ton, 2,000 pounds (900 kg)
of dry weight, as determined by certified weight tickets. No allowance
shall be made for any materials used or work done outside the limits as
established by the OWNF. a. The work performed and material furnished
as prescribed by this item and measured as provided in this item shall be
paid for at the unit price bid for cement-modified soil, which price shall
be full compensation for pulverizing the soil material; for handling; haul-
ing and spreading the dry or slurry cement mixture; for mixing the
cement with the pulverized soil; furnishing, hauling and mixing water
with the cement-soil mixture; spreading and shaping the mixture; com-
pacting the mixture, including ail rolling required for this compaction;
surface finishing;, and for all manipulation, labor, equipment, appliances,
tools and incidentals necessary to complete the work and carry out the
maintenance provisions in this specification. Cement material measured
as provided in this item shall be paid for at the unit price bid for cement
material, which price shall be compensation for furnishing the material;
for ail freight involved, for all unloading and storing; and for all labor,
equipment, fuels, tools and incidentals necessary to complete the work,
ali in accordance with the plans and these specifications.
AUGUST