0277CITY OF SOUTHLAKE
Proposed Street Standards
for
Construction
February 10, 1983
As Adopted by City Council
and Assigned Ordance
Street Composition:
The street composition in the residential development
of the City of Southlake shall consist of a two-lane street
with drainage ditches on each side. The street shall have
a crown height of six to eight inches (6" to 8") and a
crown width of thirty six feet (36') which shall include
a thirty one foot (31') wide and eight inch (8") deep
crushed stone base constructed upon a six inch (6") deep
lime stabilized subgrade, (if r~'~6ired) with a twenty four
foot (24') wide surface treatment in the center of the
said base material. The City shall make recommendation
as to the type subgrade required after sufficient information
has been provided by the developer. The surface treatment
shall be two inches (2") of hot mix asphalt. Core samples
shall be made by the developer at his expense. Exhibit "A"
attached hereto and made a part hereof sets forth the re-
quirements as stated above.
Th~ streets, including parkways, shall be excavated to
the line and grade shown on the construction plans approved
by the City Engineer.
Street Pavin9 Materials
1. Lime
Lime for stabilization shall be Type 'B" Commercial Lime Slurry
When sampled and tested according to prescribed lexas
Highway Department procedures, hydrated lime shall confor~
to the following requirements as to chemical composition:
Hydrate Alkalinity, percent by weight CA(OH)2.
Minimum 90.0%. Unhydrated Lime Content, percent
by weight CAO Maximum 5.0%.."Free Water" Content,
percent by weight H20 Maximum 4.0%.
The percent by weight by residue retained shall conform
to the following requirements:
Residue retained on a No. 6 sieve,
Maximum 0.0%
Residue retained on a No. l0 sieve,
Maximum 1.0%
Residue retained on a No. 30 sieve,
Maximum 2.5%.
Type "B" Commercial ~ime Slur~, shall be a pumpable suspension
of solids in water. The water ~r liquid portion of the slurry
shall not contain dissolved material in sufficient quantity
and/or nature injurious or objectionable for the purpose in-
tneded. The solids portion of the mixture, when considered
on the basis of "solids content", shall consist principally
of hydrated lime of a quality and fineness sufficient to meet
the above mentioned requirements as to chemical composition
and residue.
2. Crushed Stone
The materials shall be crusher-run broken stone and
shall consist of durable particles of stone mixed
with approved binding material. The processed material
shall be a Type "A", Grade 1 material, and when properly
slaked and tested, the flexible base material shall
meet the following requirements:
Retained on 1-3/4 inch sieve
Re~ained on No. 4 sieve
Retained on No. 40 sieve
0%
45 to 75%
60 to 85%
Material passing the No. 40 sieve shall be known as
"Soil Binder" and shall meet the following requirements
when prepared in accordance with THD test Method
lex-lO1-E procedure:
lhe liquid limit shall not exceed 40
The plasticity index shall not exceed l0
-2-
The percent of wear, as determined by the Los Angeles
Abrasion Test of Coarse Aggregate, AASHO Designation
T-96, with subsequent revisions, shall not exceed 50%.
3. Hot-Mix Asphaltic Concrete
Hot mix asphaltic concrete pavement shall consist of
a pavement composed of a compacted mineral aggregate
and asphaltic material. Hot mix asphaltic concrete
shall be transported to and constructed on the completed
base course or sub-base in accordance with these speci-
fications and in conformity with lines, grades, and
typical cross sections shown on the plans.
The mineral aggregate shall be composed of a coarse
aggregate, a fine aggregate, and, if required, a
mineral filler. Samples of coarse aggregate, fine
aggregate and mineral filler shall be submitted for
tests if required by the Engineer. It shall contain
not more than one (1) percent by weight of organic
matter, clays, loam, or pebbles coated therewith.
Mineral aggregate from each coarse shall meet the
quality test specified herein.
The combined minera¥ aggrega~e~ after final processing
by the mixing plant, and prior'to addition of asphalt
and mineral filler, shall have a sand equivalent value
of not less than 50, when subjected to the sand equi-
valent test as outlined in Texas Highway Department
Bulletin C-14.
The fine aggregate shall be that part of the aggregate
passing the No. l0 sieve and shall consist of sand or
screenings or a combination of sand and screenings.
The plasticity index of that part of the fine aggregate
passing the No. 40 sieve shall not be more than 6.
Sand shall be composed of durable stone particles free
from injurious foreign matter. Screenings shall be
of the same or similar material as specified for coarse
aggregate.
The coarse aggregate shall be that part of the aggregate
retained on a No. l0 sieve; shall consist of clean,
crushed, durable fragments of stone, crushed blast
furnace slag, crushed gravel, or combinations thereof
as hereinafter specified, of uniform quality throughout.
Coarse aggregate will be tested in accordance with THD
Bulletin C-11 (Decantation) and material removed shall
not be more than one percent by weight. The coarse
aggregate shall have an abrasion of not more than 40
percent loss by weight when subjected to the Los Angeles
abrasion test.
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Mineral filler shall consist of thoroughly dry stone dust,
slate dust, portland cement or other non-plastic mineral
dust approved by the Engineer. The mineral filler sha)l
be free from foreign and other injurious matter. When
tested by the method outlined in lHD Bulletin C-14, it
shall meet the following grading requirements;
Percent
by Weight
Passing a No. 30 sieve
Passing a No. 80 sieve,
not less than
Passing a No. 200 sieve,
not less than
lO0
9O
65
The asphaltic materials shall be of the grade and type
shown on the plans or approved by the Engineer.
The paving mixtures shall consist of a uniform mixture
of coarse aggregate, fine aggregate and asphaltic
material. The grading of each constituent of the mineral
aggregate shall be such as to produce, when properly
proportioned, a mixture, which, when tested in accordance
with lHD Bulletin C-j4, will conform to the limitations
for master grading given belowqfor the type specified.
Crushed stone, crushed gravel, or pea gravel may be used
in the Type "D" surface course.
For thoroughfare streets, as designated by the Engineer,
the hot mix asphaltic concrete surface course shall be
compacted to 94% density and be Type "C".
Type "C" (Coarse Graded Surface Course):
Passing 7/8" sieve 100
Passing 5/8" sieve 95 to 100
Passing 5/8" sieve, retained on
3/8" sieve 15 to 40
Passing 3/8" sieve, retained on
No. 4 sieve l0 to 35
Passing No. 4 sieve, retained on
No. l0 sieve l0 to 30
Total retained on No. l0 sieve 50 to 70
Passipg No. l0 sieve, retained
on No. 40 sieve 0 to 30
Passing No. 40 sieve, retained
on No. 80 sieve 4 to 25
Passing No. 80 sieve, retained
on No. 200 sieve 3 to 25
Passing No. 200 sieve 0 to 8
lhe asphaltic material shall form from 3.5 to 7 percent of
the mixture by weight.
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For residential streets the hot mix asphaltic concrete
surface course shall be compacted to 94% density and
by Type "D".
]spe "D" (Fine Graded Surface Course.):
Percent
by Weight
Passing 1/2" sieve 100
Passing 3/8" sieve 95 to 100
Passing 3/8" sieve, retained on
No. 4 sieve 20 to 50
Passing No. 4 sieve, retained on
No. l0 sieve 10 to 30
Total retained on No. l0 sieve 50 to 70
Passing No. lo sieve, retained
on No. 40 sieve 0 to 30
Passing No. 40 sieve, retained
on No. 80 sieve 4 to 25
Passing No. 80 sieve, retained on
on No. 200 sieve 3 to 25
Passing No. 200 sieve 0 to 8
The asphaltic materiel shall f.o~?m from 4.0 to 8.0 percent
of the mixture by weight.
CONSTRUCTION REQUIREMENTS
Subgrade Treatment:
The developer shall be required to furnish a minimum of
two (2) laboratory tests for each apparent soil type in each
block, and stating the amount of lime application required
for treatment of the subgradeo if any. Should these tests,
or any other observations by the laboratory, or the City
Engineer, indicate that a satisfactory subgrade is not being
obtained, the developer shall then submit proposed corrective
measures for consideration by the City.
All streets shall be assumed to have poor subgrades unless
and until the developer furnishes actual test data prepared
by an independent testing laboratory sufficient in the opinion
of the City to show that the subgrade is of a higher quality,
or the Ciby Engineer is satisfied that the proposed measures
of the developer are adequate for the suhgrade. Such data
shall include, but is not necessarily limited to: Liquid
Limit, Plasticity Index, and Percent Passing No. 200 Sieve.
Classification of the subgrade for evaluating the supporting
qualities shall generally apply to the top six inch (6")
layer of soil measured down from subgrade surface. In all
cases, the requirements set forth in this criteria are minimum
and the City reserves the right to require further additional
precautions or treatments consistent with sound engineering
-5-
practice when necessary to provide for other conditions not
specifically covered by this criteria.
Where the Plasticity Index of the natural soil is equal
to or exceeds twenty (20), lime stabilization shall be required.
A minimum of six percent (6%} by weight lime to a depth of
six inches (6") shall be required. Where the Plasticity
Index of the natural soil is less than twenty (20) but equal
to or greater than fifteen (15), lime stabilization may be
required if, in the opinion of the City Engineer, it is
necessary in order to achieve a proper subgrade. Soil samples
for determining the Plasticity Index of the natural soils
shall be taken at locations specified by the City Inspector
and shall be paid for by the developer. At the developer's
option and expense, a lime series test may be made by a
qualified testing firm, and lime may be applied at the optimum
rate indicated by the test.
The minimum compaction shall be ninety five percent (95%)
as per AASHO designation T180. When proper subgrade cannot
be constructed in soils having a low plasticity index, cement
stabilization may be required when deemed necessary.
A sufficient number of tests shall be performed by an
independent testing laboratory, to show the quality of the
subgrade throughout the sub-divis~i~n, prior to the placement
of the surface course. Generally, this will consist of one
test per two hundred (200) feet of street. The exact number
and location shall be specified by the City Inspector. Where
other conditions apart from the physical properties indicate
a special problem such as springs or seepage, drastic material
changes from point to point, etc., appropriate studies shall
be furnished by a Registered Professional Engineer employed
by the developer to indicate the corrective measures needed,
subject to approval by the City of Southlake.
Crushed Stone Base:
The material shall be delivered in approved vehicles
and it shall be the charge of the Contractor that the required
amount of specified material shall be delivered to secure the
proper thickness of completed base course. Material deposited
upon the subgrade shall be spread the same day unless otherwise
directed by the City Inspector in writing. In the event inclement
weather ~r other unforeseen circumstances render impractical
the spreading of the material during the first 24-hour period,
the material shall be scarified and spread as directed by the
City Inspector. The material shall be sprinkled, if directed,
and then bladed, dragged and shaped to conform to typical
sections shown on the plans. All areas of segregated coarse
or fine material shall be corrected or removed and replaced
w~th well graded material as directed by the City inspector.
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If additional binder is considered desirable or necessary
after the material is spread and shaped, it shall be furnished
and applied in the amount directed by the Inspector. Such
binder material shall be carefully incorporated with the
material in place by scarifying, harrowing, brooming or by
other approved methods.
The course shall then be sprinkled as required and
rolled as directed until a uniform compaction is secured.
Through this entire operation the shape of the course shall
be maintained by blading and the surface upon completion
shall be smooth and in conformance with the typical sections
shown on the plans and to the established lines and grades.
The surface on which pavement is to be placed shall not show
deviations in excess of one-fourth (1/4") in cross-sections
and in a length of five (5) feet, nor a deviation in excess
of one-half (1/2") inch in sixteen (16) feet measured
longitudinally. Such deviations shall be corrected by
loosening, adding or removing material, reshaping and re-
compacting by sprinkling and rolling. All irregularities,
depressions or weak spots which develop shall be corrected
immediately by scarifying the areas affected, adding suitable
material as required, reshaping and recompacting by sprinkling
and rolling.
After final compaction, a field density test shall be
made at intervals of 200 feet. Intermediate points may be
tested if required by the Inspector and the cost of inter-
mediate tests shall be borne by the Contractor. If any
density test should indicate that the base material does not
meet the compaction requirements, the base material shall be
recompacted until the required density is obtained. All
re-testing required due to improper compaction shall be paid
for by the Contractor.
Asphaltic base and all surfaces of curbs, gutters,
headers, manholes, valve boxes, etc., that will be in con-
tact with the asphaltic concrete mixture, shall be given a
thin uniform coating of OA-90 tack coat. The Contractor
shall use caution to protect the curb and gutter, if any is
present, during placement of the tack coat.
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A.~]~ ha 1 t Pavement:
Before the application of asphaltic material is begun,
the sub-base or crushed stone base will be cleaned to the
satisfaction of the City Inspector. After the cleaning
procedure is completed, a prime coat of MC-1 asphalt will
be applied to the sub-base or crushed stone base at the
rate of O.lO to 0.25 per square yard.
After spreading, the hot mix shall be thoroughly com-
pacted by a tandem power driven roller, weighing not less
than ten (10) tons, as soon after being spread as it will
bear the roller without undue displacement. Rolling shall
start longitudinally at the sides and proceed toward the
center of the pavement overlapping on successive trips by
at least one-half the width of the wheel. The pavement
shall be rolled diagonally in two directions with a tandem
roller, weighing not less than ten (10) tons, the second
diagonal rolling shall cross the lines of the first.
Pneumatic rollers shall be used for final rolling.
The pavement shall be compressed thoroughly and uni-
formly and when tested in accordance with the THD Bulletin
C-14 shall meet the following requirements:
Laboratory Density (THD Bulletin C-14)
Minimum 94-~ercent
Maximum 99 percent
Optimum 97 percent
Patches to Street (Street Cuts):
When it becomes necessary to cut an existing street for
the installation of utility lines, the following repair
standard shall be used for repair to the excavated section
of street:
STREET SURFACE-~
'!
.,SAW CU: (TYE)
"\~\\\\\\\~' ~.~'~.~.¥~_ ~2' H.M.A.C. SURFACE COURSE
' ' ' ' ' ]COM~TED SAND BACKFILL
6" .:. ' '.. (s5% C~PA~ON)
~ ~UTILITY LI~
~ ~ ( WAT~,R ,,EWER, ,A,, ETC. )
~ M ~ 6 CUSHION S~ND
~ATURAL G~
All street patches to street cuts shall be subject to
approval by the City Inspector as deemed necessary.
-8-
Culvert and Ditch Velocit~ Limitations:
When storm water runoff is carried in culverts or ditches
either under or along the side of streets, the following flow
limitations shall apply to the velocity of the storm water:
VELOCITY LIMITATIONS
Soil Conditions
Maximum Allowable
Velocity {f.p.s.)
Earth 6
Sod earth (or hydro-mulch) B
Paved or riprap apron 15
Shale l0
Rock 15
The developer shall provide construction plans prepared
by a Registered Professional Engineer with lines and grades
clearly shown for the drainage facilities. There shall be
sufficient information shown to determine the velocity of
water in ditches or discharging from culverts. The velocity
of water shall be indicated on the construction plans.
The table of velocity limitations shall be used to
determine the type of measures to .~e used to prevent ex-
cessive erosion. The City Engin~e~ or Inspector shall make
recommendations after sufficient information has been pro-
vided and analyized. If in the opinion of the City Engineer
or Inspector, adequate measures are not being taken to prevent
excessive erosion to ditches and channels, the developer
shall be required to revise the plans according to standard
practices for good construction and revised plans shall be
submitted for approval. Such revisions might require
flatter grades, wider ditches, or both, concrete lining,
hydro-mulching, or other measures deemed necessary to prevent
excessive erosion to ditches or channels.
-9-
~L SO' _~ .
::i.,
it, e I 6 J25J ,'~1 ,,-,~ l ~,' ~,
~ 1 I-I,~ ~,,,,' .31 I
/I .... D_._I__I I I
ZMAX*~ SURFACE TREATMENT/* x. ~'a' ~*r,,,e,~-,', ~*-,*,,~ ..... '*'-*.,~'..,. ~
~'6' LIME STABlUZED SU~GRADE ,NOTE STONE BASE TO BE
(IF REGUIRED) ' GRADED TO BLEND
WITH ELEVATION OF
H.M.AC., PRIOR TO
STANDARD SUB-DIVISION PAVED STREET CO""L£T~OHOE
'" PROJECT.
"ESTATE TYPE
EXHIBIT *A'
-lO-
EXHIBIT "B"
IRREVOCABLE LETTER OF CREDIT
NUMBER
TO:
RE:
City of Southlake
667 North Carroll Avenue
Southlake, Texas 76092
(Development or Subdivision Title)
City of Southlake
County, Texas
Gentlemen:
We hereby authorize you to draw on us for account of
, up to the aggregate amount of $
available by your drafts at three (3) days after sight. Drafts drawn
hereunder must either (a) be signed in }he manner, set out in (1) below or
(b) be signed on behalf of the City-of'~outhlake and be accompanied by
the certificate set out in (2) below.
(1) The form of signature for drafts drawn under method (a)
is as follows:
"City of Southlake"
By
Mayor
and "Developer"
By
Title
(2) Drafts signed only on behalf of the City of Southlake shall
be accompanied by the fo]lowing certificate:
" , Mayor of the City of Southlake, and
, City Secretary of the City of
Southlake, Texas.
"Resolved that performance by
under its Developer's Agreement has been unsatisfactory and
that the City of Southlake, Texas is entitled under its
agreement with to draw on Letter of
Credit No. issued by the
in the sum of $ and a draft in such sum shall
be drawn and presented to for payment,
with a certificate of this resolution attached."
EXHIBIT "B" CONTINUED
Date:
Secretary of the City of
Southlake
Mayor of the City of
Southlake
Drafts drawn under this Letter of Credit must recite that they are drawn
under Letter of Credit No. , and must be presented to drawee
not later than Amounts drawn hereunder must be
noted on the reverse side of this letter.
This Letter of Credit applies only to the Developer of the above reference
subdivision.
Very truly yours,
By:
Title