Tài liệu SECTION 05100 PRIME COAT pdf

DIVISION 5 - ASPHALT PRODUCTS AND PAVEMENTS Prime Coat - Section 05100
SECTION 05100 - PRIME COAT
TABLE OF CONTENTS
1. DESCRIPTION 1
2. REFERENCE STANDARDS FOR PRIME COAT 1
3. MATERIALS FOR PRIME COAT 1
4. SUBMITTALS 2
5. CONSTRUCTION REQUIREMENTS 2
5.1 Surface Condition and Weather Limitation 2
5.2 Quality of Work and Rectification of Unsatisfactory Work 2
6. WORK CONDITIONS 3
7. SURFACE PREPARATION 3
8. RATE AND TEMPERATURE OF APPLICATION 4
8.1 Rate of Application 4
8.2 Spraying Temperatures 4
8.3 Excessive Heating 4
8.4 Precautions 5
8.5 Application of the Coating 5
9. MAINTENANCE OF PRIME COAT 6
10. FIELD QUALITY CONTROL AND TESTING 7
11. EQUIPMENT 8
11.1 General 8
11.2 Distributor Capacity 8
11.3 Distributor Application 8
11.4 Distributor Spray Bars and Spreading Equipment 8
11.5 Instrumentation/Calibration 9
11.6 Spray Chart and Operations Manual 9
11.7 Unacceptable Equipment 9
12. MEASUREMENT AND PAYMENT 10
12.1 Measurement for Payment 10
12.2 Measurement of Rectified Work 10

12.3 Basis of Payment 10
TECHNICAL SPECIFICATIONS - DIVISION 5 31/01/14 05100 - i
DIVISION 5 - ASPHALT PRODUCTS AND PAVEMENTS Prime Coat - Section 05100
TECHNICAL SPECIFICATIONS - DIVISION 5 31/01/14 05100 - ii
DIVISION 5 - ASPHALT PRODUCTS AND PAVEMENTS Prime Coat - Section 05100
SECTION 05100 - PRIME COAT
1. DESCRIPTION
(a) Prime Coat furnished and applied by the Contractor shall conform to the
requirements and procedures provided in this Specification section.
(b) The work shall consist of furnishing and applying liquid asphalt to
previously prepared and approved absorbent surfaces (subgrade, granular
subbase or aggregate base course) immediately prior to placing
superimposed construction in accordance with the Specification
requirements. Prime Coat shall be applied to the full width indicated on the
Drawings, or as required by field conditions. Such work shall be performed
as specified herein or as directed by the Engineer.
2. REFERENCE STANDARDS FOR PRIME COAT
The latest printing of the following standards and tests shall apply to Prime Coat.
♦ AASHTO M 82 Cut-back Asphalt Medium Curing type
♦ AASHTO M 140 Anionic Emulsified Asphalt
♦ AASHTO M 208 Cationic Emulsified Asphalt
♦ AASHTO M 226 Viscosity Graded Asphalt Cement
♦ AASHTO T 179 Effect of Heat and Air on Asphalt Materials
(Thin-film Oven Test)
3. MATERIALS FOR PRIME COAT
(a) The materials for Prime Coat shall be either AC-20 grade asphalt cement
(which is approximately equivalent to 60/70 Pen.) diluted with kerosene or
medium curing cut-back asphalt grade MC-70.
(b) The AC-20 grade asphalt cement shall conform to AASHTO M 226 standard
for viscosity graded asphalt cement. The MC-70 shall conform to AASHTO

M 82 for medium curing cut-back asphalt.
(c) When AC-20 is to be diluted with kerosene, the proportion of kerosene
dilutent used shall be as directed by the Engineer.
(d) Cover aggregate for Prime Coat shall be screened natural grit or crushed
stone, free from weak soft particles, cohesive or organic matter. Not less
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than 98 percent shall pass the 9.5 mm ASTM sieve and not more than 2
percent shall pass the 2.36 mm (No. 8) sieve.
4. SUBMITTALS
The Contractor shall provide the Engineer with the following:
(a) A 5-litre sample of any bituminous material that the Contractor proposes to
use in the work, together with a certificate from the Manufacturer, shall be
submitted before construction begins. The certificate must state that the
binder complies with the relevant specification and grade requirements for
the prime coat, given in this Specification section.
(b) A satisfactory record of the calibration certificates of all instruments, gauges
and the dipstick for the bitumen distributor, shall be submitted not less than
30 days before construction begins. The dipstick instrument and gauges
shall be calibrated, the accuracy shall be shown in the calibration certificate
and the date of calibration shall be no longer than two years before the start
of construction.
(c) Spray chart, meeting the requirement of sub-section 11.6 of this Specification
section shall be submitted before construction begins, so that equipment
checks can be carried out.
(d) Samples of materials used in each day’s work shall be submitted. Daily
records of sealing works done and material application rates shall be
submitted in accordance with this Specification section, the Drawings or as
directed by the Engineer.
5. CONSTRUCTION REQUIREMENTS

5.1 SURFACE CONDITION AND WEATHER LIMITATION
Prime Coat shall be applied only on surfaces, which are dry or slightly moist.
Prime Coat shall not be applied during high winds, rain, foggy weather or if rain
threatens.
5.2 QUALITY OF WORK AND RECTIFICATION OF UNSATISFACTORY WORK
(a) The finished coat shall completely cover the area treated and be of uniform
appearance, without missed areas or streaks or “rich” areas of accumulated
bitumen.
(b) After curing for four to six hours, the binder shall have soaked into the base
course, leaving behind only sufficient binder to ensure that the surface is
uniformly black or dark grey in color and non-porous. The texture of the
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base course aggregate surface shall be discernable and there must be no
pools or films of binder or binder mixed with aggregate fines thick enough
to scrape off the surface with a knife.
(c) Rectification of unsatisfactory Prime Coat shall be as directed by the
Engineer and may include removal of excess material, the use of cover
aggregate, or the application of additional coatings as required. Minor
potholing of a Prime Coat shall be promptly patched. The Engineer may
require widespread potholing or other damage to be rectified by scarifying
and recompaction or replacement of the base layer followed by re-
application of the Prime Coat.
6. WORK CONDITIONS
(a) The work shall be carried out in such a manner as to offer the least
inconvenience to traffic and without damage to the work.
(b) The surfaces of structures or trees or property adjacent to the areas being
treated shall be protected so as to prevent their being marred or spattered.
(c) No bituminous material shall be discharged into any side ditch or drain.
(d) The Contractor shall provide and maintain at the heating site, adequate fire

prevention and control measures, and also first aid supplies and facilities.
(e) The Contractor shall be responsible for all the consequences of traffic being
admitted too early to newly laid Prime Coat, and he shall prohibit such
traffic when necessary by the provision of a detour or by half-width
construction.
7. SURFACE PREPARATION
(a) Prior to the application of the binder, loose dirt and other objectionable
material shall be removed from the surface by means of power broom or
blower or both. If this does not provide a uniformly clean surface additional
sweeping shall be done by hand using stiff brooms. Sweeping shall extend
at least 20 centimeters beyond each edge of the area to be sprayed.
(b) Adherent patches of objectionable material shall be removed from the
surface by steel scraper or other approved method and where the Engineer
so directs the scraped area shall be washed down with water and hand
brooms.
(c) For Prime Coats on Aggregate Base, the final swept surface finish shall
consist of a flat, tight, clean mosaic of coarse and fine aggregate, a surface
consisting only of fine aggregate shall not be acceptable.
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(d) The Engineer may direct that a light application of water be made just prior
to the application of liquid asphalt to facilitate penetration. The Engineer
will not permit priming when there is free water present on the surface.
(e) No application of bituminous material shall be undertaken until the
pavement has been prepared to the satisfaction of the Engineer.
8. RATE AND TEMPERATURE OF APPLICATION
8.1 RATE OF APPLICATION
The Contractor shall carry out field trials under the supervision of the Engineer to
establish the appropriate application rate and such trials will be repeated, as
directed by the Engineer, whenever the type of bituminous material or the type of

surface changes. The rate of application shall be within the range 0.45 – 2.25
liters/m
2
and/or as otherwise approved by the Engineer.
8.2 SPRAYING TEMPERATURES
Spraying temperatures for Prime Coat shall comply with Table 1. Spraying
temperatures for cut-back asphalt cement with kerosene contents differing from
those listed shall be obtained by interpolation.
TABLE 1
Spraying Temperatures (Prime Coat)
TYPE OF MATERIAL SPRAYING TEMPERATURE RANGE
Cutback, 50 pph kerosene
(MC-70 grade cutback)
70 + 10
0
C
Cutback, 75 pph kerosene
(MC-30 grade cutback)
45 + 10
0
C
Cutback, 100 pph kerosene 30 + 10
0
C
Cutback, more than 100 pph
kerosene
Not heated
Note: The abbreviation pph shown in Table 1 means parts of kerosene per 100
parts of asphalt cement by volume.
8.3 EXCESSIVE HEATING

Heating quantities in excess of the requirements or prolonged heating at high
temperatures should be avoided. Any material which, in the opinion of the
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Engineer, has been damaged by overheating shall be rejected and shall be
replaced at the Contractor’s expense.
8.4 PRECAUTIONS
Extreme care should be used when heating any cut back asphalt cement. Open
flames or sparks must not be permitted close to these materials. Controlled heat
should be applied in heating kettles, mixers, distributors or other equipment
designed and approved for the purpose. Open flames must not be used to inspect
or examine drums, tank cars or other containers in which these materials have
been stored. All vehicles transporting these materials must be properly vented.
Only experienced personnel must be permitted to supervise the handling of these
materials.
8.5 APPLICATION OF THE COATING
(a) The length of the surface to be sprayed by each run of the distributor shall
be measured and marked on the ground. For Prime Coats, paint or string
line shall define the boundaries of the area to be sprayed.
(b) Bituminous material shall be so applied that a uniform distribution is
obtained at all points. The uniform application of bituminous material at the
rate instructed shall be made by means of the bitumen distributor bar spray,
except where the use of the distributor is not practicable for the application
to small areas, the Engineer may then approve the limited use of hand spray
equipment.
(c) The bitumen distributor shall be operated in accordance with the approved
spray chart. Pump speed, vehicle speed, bar height and nozzle settings shall
be set in accordance with the chart before and during each spraying
operation.
(d) Generally, Prime Coat shall be applied in a single spraying operation.

However, where slowness of drying is a problem, or where the coating
tends to flow off the surface, the approved quantity of coating may be
applied in two spraying operations, the first coat being allowed to dry
before application of the second.
(e) When directed, the bituminous material shall be applied in spray runs of
approximately one half or less of the width of the completed surface and
when so applied there shall be an overlap of 20 cm along the adjoining
edges. The sprayed width shall be greater than the specified width of
treatment at the edge of the pavement surface or edge of shoulder to allow
for the reduced bitumen rate at the edge where no jet overlap occurs.
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(f) Protective strips of building paper or similar non-porous, flexible material
shall be spread on the surface at the start and end of each spray run. Flow
through the nozzles shall be started and stopped entirely on the strips, so
that all nozzles operate properly on the entire length of road being treated.
The width of the strips shall be sufficient to ensure that this is achieved.
(g) The bitumen distributor shall start moving no less than 5 meters in advance
of the area to be sprayed so as to be travelling at the correct speed when the
spray bar reaches the paper strip and this speed shall be maintained until
past the intended finishing point of the binder application. The strips shall
be promptly removed and disposed of in a manner satisfactory to the
Engineer.
(h) Provision shall be made for 10 percent, or such other percentage as may be
determined by the Engineer, of the rated capacity of the bitumen distributor
to be retained in the tank at the completion of each run, so as to avoid air
entertainment within the delivery system and provide for any minor excess
in the rate of application.
(i) The amount of binder used in each sprayer run shall be measured by
dipping the distributor binder tank on level ground immediately before and

after each run.
(j) The average binder application rate achieved on each sprayer run,
calculated as the volume of binder used divided by the product of the
number of nozzles in use and the spacing between nozzles, shall lie within +
5% of the rate directed by the Engineer. The achieved application rate shall
be calculated before any subsequent spray run is made and any necessary
adjustments shall be made to ensure that the directed rate of application is
maintained in subsequent runs.
(k) Spraying shall cease immediately if any defect develops in the spraying
equipment and shall not recommence until the fault has been rectified
(l) Following the spraying of the binder, any areas of pooling or excessive
binder shall be continually redistributed across the sprayed surface, until
absorption and curing of the binder prevents further movement of the
binder. A pneumatic typed roller shall be used for this purpose.
9. MAINTENANCE OF PRIME COAT
(a) The Contractor shall maintain the primed surface to the specified standard
until it is overlaid by the subsequent course. The subsequent course shall be
applied only after sufficient time has elapsed to allow the primer binder to
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be fully absorbed and to harden, in order to avoid flushing and softening of
the subsequent course.
(b) The delay period, which shall be as directed by the Engineer, shall be a
minimum of two and generally not more than fourteen days, depending on
the traffic, weather, binder and base materials.
(c) Traffic shall not be permitted on the primed surface until the bituminous
material has penetrated and dried and, in the opinion of the Engineer, will
not pick up under traffic. In exceptional circumstances where it becomes
necessary to permit traffic prior to that time, but in no case sooner than four
hours after the application of the bituminous material, clean cover aggregate

shall be applied as directed by the Engineer and traffic may be permitted to
use the lanes so treated. Cover aggregate shall be spread from trucks in such
a manner that no wheel will travel on uncovered wet bituminous material.
When applying cover aggregate to a treated lane that adjoins a lane yet to be
treated, a strip at least 20 cm wide along the adjoining edge shall be left
uncovered, or if covered shall be uncovered when the second lane is being
prepared for treatment, in order to permit an overlap of bituminous material
as required above. The use of cover aggregate shall be the minimum extent
possible.
10. FIELD QUALITY CONTROL AND TESTING
(a) A bitumen sample and certificate shall be provided for each delivery of
bitumen to the site of the works.
(b) Samples of the Prime Coat shall be taken from the distributor as directed by
the Engineer.
(c) The bitumen distributor shall be inspected and tested as follows:
♦ Prior to the commencement of spraying works on the Contract;
♦ Every 6 months or every 150,000 liters of binder sprayed by the
distributor, whichever is the more frequent;
♦ Following any accident or modification to the distributor, or any other
occurrence, which in the opinion of the Engineer warrants rechecking
the distributor.
(d) The result of the wet sieve testing of the proposed cover aggregate shall be
submitted to the Engineer for approval prior to any use of that aggregate.
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(e) A detailed written record of daily surfacing operations, including the
location, binder used on each sprayer run, application rates achieved, and
area covered shall be made and submitted to the Engineer.
11. EQUIPMENT
11.1 GENERAL

The equipment used by the Contractor shall include a power broom and/or a
power blower, a pressurized bitumen distributor, equipment for heating
bituminous material and, for Prime Coat work, a pneumatic tired roller or other
means of dispersing excess primer binder. The Engineer will not permit the use of
gravity distributors.
11.2 DISTRIBUTOR CAPACITY
The distributor shall have a minimum capacity of 1,000 litters.
11.3 DISTRIBUTOR APPLICATION
(a) The distributor shall be so designed, equipped, maintained and operated
that bituminous material at even heat may be applied uniformly on variable
widths of surface, at a controlled rate of transverse and longitudinal spread
within ± 10 percent of the required rate of application.
(b) When so directed by the Engineer, the Contractor shall make equipment and
operators available for field testing and shall supply any other assistance
required for this purpose.
(c) The transverse distribution of bitumen application rates produced by the
distributor shall be tested by passing the spray bar over a test area laid with
25 cm x 25 cm sheets of absorbent material with a binder-proof backing,
which are weighed before and after the spray application. The difference in
weight shall be used in determining the spraying rate actually applied to
each sheet and the variation from the mean rate for any sheet across the full
width sprayed shall not exceed 15 percent.
11.4 DISTRIBUTOR SPRAY BARS AND SPREADING EQUIPMENT
Spray bars shall be of the full circulating type. Spray bar extensions shall also be of
the full circulating type. The spray bar shall be adjustable to maintain a constant
height above the surface to be treated. The spray bar nozzles shall be slotted and
shall be of such design so as to provide a uniform unbroken spread of bituminous
material on the surface. Levers shall operate the valves so that one or all valves
may be quickly opened or closed in one operation. The distributor and booster
tanks shall be so maintained at all times as to prevent dripping of bituminous

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material from any part of the equipment. A device for hand spraying of the
bituminous liquid shall also be included as part of the distributor.
The spreading equipment shall be provided with a separate power unit for the
pump or a variable displacement pump driven by a hydrostatic transmission that
results in a uniform application of bituminous material, in controlled amounts.
The distributor shall have satisfactory heating equipment in order to provide the
full range of application temperatures for the bituminous material being used.
11.5 INSTRUMENTATION/CALIBRATION
Distributor equipment shall include a tachometer, pressure gauges, a calibrated
tank dipstick, a thermometer for measuring the temperature of the tank contents
and an instrument for measuring the speed of travel at low speed. All measuring
equipment on the distributor shall have been recently calibrated and an accurate
and satisfactory record of such calibration shall be supplied to the Engineer.
11.6 SPRAY CHART AND OPERATIONS MANUAL
(a) The distributor shall be equipped with a spray chart and operations manual,
which shall be carried with the sprayer, in good condition, at all times.
(b) The operations manual shall include pipe flow diagrams and full
instructions for all operations of the distributor.
(c) The spray chart shall show the relationship between speed and application
rate for the bitumen distributor being used as well as the relationship
between pump speed and the number of nozzles in use, based on a constant
bitumen output per nozzle. The constant nozzle output (liters/min) shall be
noted on the spray chart as well as the spraying pressure.
(d) The spray chart should also show the height of the spray bar from the
surface and the correct horizontal angle of the spray nozzles to ensure triple
overlap of the nozzle fans (i.e. the width of road coated by each nozzle is
exactly three times the spacing between nozzles).
11.7 UNACCEPTABLE EQUIPMENT

(a) The Engineer will have the right to stop the use of any equipment or plant
which he deems to be inferior to the quality required and to instruct the
removal of such equipment and to have it replaced by suitable equipment or
to alter the method of operation at any time.
(b) The Contractor shall immediately comply with such instructions without
being entitled to any indemnities or extensions as a result of such
instructions. The Contractor shall not be allowed to use any equipment or
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plant before obtaining the approval of the Engineer, and the Contractor shall
undertake to follow sound technical methods in operation and to engage
skilled and trained operators, mechanics and labor to carry out the works.
The Engineer will have the right to expel any operators, mechanics or labor
and to instruct suitable replacement thereof at any time he deems such
action is necessary.
12. MEASUREMENT AND PAYMENT
12.1 MEASUREMENT FOR PAYMENT
(a) The quantity of asphaltic material measured for payment shall be the actual
number of square meter coverage accepted.
(b) Any cover aggregate used shall be considered incidental to the work of
achieving a satisfactory Prime Coat and shall not be measured or paid
separately.
(c) The work of preparing and maintaining the formation on which Prime Coat
is to be placed will not be measured or paid under this Specification section.
(d) Final cleaning and preparation of the surface and maintenance of the
completed prime coated surface shall be considered incidental to the work
of achieving a satisfactory Prime Coat and shall not be measured or paid
separately.
12.2 MEASUREMENT OF RECTIFIED WORK
Where rectification of unsatisfactory Prime Coat has been directed by the

Engineer, the quantities to be measured for payment shall be those that would
have been paid if the original work had been acceptable. No additional payment
will be made for the extra work or quantities or testing necessitated by the
rectification.
12.3 BASIS OF PAYMENT
The quantities as determined above shall be paid for in accordance with
applicable Unit Prices as indicated on the Bid Price Schedule. Payment shall be
deemed full compensation for furnishing and placing all the material, including
any cover aggregate and including all labor, equipment and tools, and any
incidentals necessary to complete and maintain the work prescribed in this
Specification section.
Pay Item Description Unit
05100-1 Prime Coat m
2
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