Republic of the Philippines
Department of Public Works and Highways
WELCOME
Elvira Cruz Alonzo-Belza
Engineer II - QAHD
Republic of the Philippines
Department of Public Works and Highways
Determination of Moisture Content
The behaviour of a soil is markedly influenced by
the amount of moisture it contains.
By definition, moisture content is the ratio of the
weight/mass of water in the soil or aggregates
to the weight/mass of the dry soil or aggregates,
it has been dried to constant weight/mass at a
temperature of 110OC ± 5OC.
Sieve Analysis
Grain size analysis is the determination of
size distribution in aggregates by sieve
analysis.
Determination of Liquid Limit
The liquid limit defined as the lowest
moisture content at which the soil will flow
upon the application of a very small shearing
force.
Determination of
Plasticity Index
Plastic
Limit
and
The plastic limit is defined as the minimum
moisture content at which the soil can be
readily molded without breaking or crumbling.
Plasticity index indicates compressibility; high
P.I means high degree of compressibility of a
soil. It is also related to permeability: the
higher the P.I. the lower the permeability, and
vice versa
Compaction Test /
Relation Test of Soil
Moisture
Density
Compaction of soil mass involves the application
of energy and addition of water as lubricant. It
results in reduction of pore spaces and increase
of density by rearrangement of particle grains.
Thus, the mass becomes more stable and
impermeable, which are desirable characteristics
of foundation.
California Bearing Ratio Test
This method covers the determination of the
bearing ratio of soil when compacted and
tested in the laboratory by comparing the
penetration load of the soil to that of a
standard material.
Abrasion Test
This test evaluates the structural strength
of coarse aggregate. It gives an
indication of quality as determined by
resistance to impact and wear.
Determination of Density of Soil In-Place
by the Sand-Cone Method (Field Density
Test)
Density of soil is defined as the weight/mass
per unit volume. It is a very significant
engineering property of soils as strength is
dependent upon density.
The field density test is widely used as a
control test in embankment, of base course
construction to ensure adequate compaction.
 Aggregate shall consist of hard, durable
particles or fragments of crushed stone,
crushed slag, or crushed or natural gravel
and filler of natural or crushed sand or
other finely divided mineral matter. The
composite material shall be free from
vegetable matter and lumps or balls of
clay, and shall be of such nature that it can be
compacted readily to form a firm, stable
subbase.
 Grading Requirements
Sieve Designation
Mass Percent
Passing
Standard, mm
Alternate US
Standard
50
2”
100
25
1”
55 - 85
9.5
3/8”
40 – 75
0.075
No. 200
0 - 12
 The fraction passing the 0.075 mm (No. 200) sieve shall not be
greater than 0.66 (two-thirds) of the fraction passing the 0.425
mm (No. 40) sieve.
 The fraction passing the 0.425 mm (No. 40) sieve shall have a
liquid limit not greater than 35 and plasticity index not
greater than 12 as determined by AASHTO T 89 and T 90,
respectively.
 The coarse portion, retained on a 2.00 mm (No. 10 sieve), shall
have a mass percent of wear not exceeding 50 by the Los Angeles
Abrasion Test as determined by AASHTO T 96.
 The material shall have a soaked CBR value of not less than
30% as determined by AASHTO T 193. The CBR value shall be
obtained at the maximum dry density and determined by
AASHTO T 180, Method D.
 PLACING
The aggregate subbase material shall
be placed at a uniform mixture on a
prepared subgrade in a quantity which will
provide the required compacted thickness.
When more than one layer is required,
each layer shall be shaped and compacted
before the succeeding layer is placed.
 SPREADING AND COMPACTING
When uniformly mixed, the mixture shall be spread to the
plan thickness, for compaction.
When the required thickness is 200 mm or less, the
material may be spread and compacted in one layer. Where the
required thickness is more than 200 mm, the aggregate subbase
shall be spread and compacted in two or more layers of
approximately equal thickness, and the maximum compacted
thickness of any layer shall not exceed 200 mm. All subsequent
layers shall be spread and compacted in a similar manner.
The moisture content of subbase material shall, if
necessary, be adjusted prior to compaction by watering with
approved sprinklers mounted on trucks or by drying out, as required
in order to obtain the required compaction.
 SPREADING AND COMPACTING
Immediately
following
final
spreading
and
smoothening, each layer shall be compacted to the full width
by means of approved compaction equipment. Rolling
shall progress gradually from the sides to the center,
parallel to the centerline of the road, and shall continue
until the whole surface has been rolled.
Compaction of each layer shall continue until a field
density of at least 100 percent of the maximum dry
density determined in accordance with AASHTO T 180,
Method D has been achieved. In-place density determination
shall be made in accordance with AASTHO T 191.
 TRIAL SECTIONS
Before subbase construction is started, the Contractor shall
spread and compact trial sections as directed by the Engineer. The
purpose of the trial sections is to check the suitability of the
materials, the efficiency of the equipment and the
construction method which is proposed to be used by the
contractor. Therefore, the contractor must use the same material,
equipment and procedures that he proposes to use for the main work.
One trial section of about 500 m2 shall be made for every
type of material and/or construction equipment/procedure
proposed for use.
 TRIAL SECTIONS
If the basic conditions regarding the type of
material or procedure change during the execution of the
work, new trial sections shall be constructed.
 TOLERANCES
Permitted variation from design
THICKNESS OF LAYER
± 20 mm
 METHOD OF MEASUREMENT
Aggregate Subbase Course
measured by the cubic meter (m3)
will
be
 For every
300 m3 or fraction thereof:
1-G, Grading Test
1-P, Plasticity Test (PL, LL, PI)
 For every
1500 m3 or fraction thereof:
1-C, Compaction Test
1-Q, Quality test for: (Grading, Plasticity
and Abrasion)
 For every
2500 m3 or fraction thereof:
1-CBR, California Bearing Ratio
For every layer of 200 mm
of compacted depth/based
on the results of compaction
trials
At least one group of three insitu density tests for each 500
m2 or fraction thereof.
Department Order no. 70 s. 2016
 Aggregate for base course shall consist of hard,
durable particles or fragments of crushed
stone, crushed slag, or crushed or natural
gravel and filler of natural or crushed sand
or other finely divided mineral matter. The
composite material shall be free from
vegetable matter and lumps or balls of
clay, and shall be of such nature that it can be
compacted readily to form a firm, stable base.
 Grading Requirements
Sieve Designation
Mass Percent Passing
Standard, mm
Alternate US
Standard
Grading A
Grading B
50.0
2”
100
37.5
1 ½”
-
100
25.0
1”
60 – 85
-
19.0
¾”
-
60 – 85
12.5
½”
35 – 65
-
4.75
No. 4
20 – 50
30 – 55
0.425
No. 40
5 – 20
8 – 25
0.075
No. 200
0 – 12
2 - 14
 The fraction passing the 0.075 mm (No. 200) sieve shall
not be greater than 0.66 (two-thirds) of the fraction
passing the 0.425 mm (No. 40) sieve.
 The fraction passing the 0.425 mm (No. 40) sieve shall
have a liquid limit not greater than 25 and plasticity
index not greater than 6 as determined by AASHTO T 89
and T 90, respectively.
 The coarse portion, retained on a 2.00 mm (No. 10 sieve),
shall have a mass percent of wear not exceeding 50 by the
Los Angeles Abrasion Test as determined by AASHTO T 96.
 The material passing the 19 mm sieve shall have a soaked
CBR value of not less than 80% as determined by
AASHTO T 193. The CBR value shall be obtained at the
maximum dry density (MDD) and determined by AASHTO
T 180, Method D.
 PLACING
It shall be same in accordance with all the
requirements of Subbase Course.
 SPREADING AND COMPACTING
It shall be same in accordance with all the
requirements of Subbase Course.
 TRIAL SECTIONS
It shall be same in accordance with all the
requirements of Subbase Course.
 TOLERANCES
Permitted variation from design
THICKNESS OF LAYER ± 10 mm
 METHOD OF MEASUREMENT
Aggregate Base Course will
measured by the cubic meter (m3)
be
 For every
300 m3 or fraction thereof:
1-G, Grading Test
1-P, Plasticity Test (PL, LL, PI)
 For every
1500 m3 or fraction thereof:
1-C, Compaction Test
1-Q, Quality test for: (Grading, Plasticity
and Abrasion)
 For every
2500 m3 or fraction thereof:
1-CBR, California Bearing Ratio
 For every layer of 200 mm of
compacted depth/based on the
results of compaction trials.
At least one group of three in-situ
density tests for each 500m2 or
fraction thereof.
Republic of the Philippines
Department of Public Works and Highways
 This Item shall consist of preparing
and treating an aggregate base
course with material in accordance
with the Plans and Specifications,
preparatory to the construction of a
bituminous surface course
 Bituminous material shall be either
Rapid Curing (RC) or Medium
Curing (MC) Cut-back Asphalt,
whichever is called in the Bill of
Quantities. The type and Grade shall
be specified in the Special Provisions.
 Surface Condition:
Prime Coat shall be applied only to
surfaces which are dry or slightly
moist. No prime coat shall be applied
when the weather is foggy or rainy.
 The tanks shall have a heating device able to
heat a complete charge of bituminous liquid
to 180oC. The heating device shall be such
that overheating will not occur. The liquid
shall be insulated in such a way that the drop
in temperature when the tank is filled
with bituminous liquid at 180oC and not
heated will be less than 2oC per hour.
The distributor shall be designed so that the
deviation from the prescribed rate of application
does not exceed 10% and shall be equipped with a
device for hand spraying of the bituminous liquid
 The rate of application of the
bituminous material shall be within
the range of 1 to 2 L/m2
 The prime coat shall be left undisturbed for a period
24 hours or until such time that it has sufficiently cured
determined by the Engineer, and shall not be opened
traffic so that it will not be picked up by the wheels
passing vehicles.
of
as
to
of
 Care shall be taken that the application is not in excess of
the specified amount. Any excess shall be blotted with
sand or removed as directed by the Engineer.
 Bituminous Prime Coat shall be
measured by the area covered in
square meter (m2 )
1-Q, Quality Test for every
40 tonnes or 200 drums
 This Item shall consist of preparing and
treating an existing bituminous or
cement
concrete
surface
with
bituminous material in accordance with the
Plans and Specifications, preparatory to the
construction of a bituminous surface course
 Bituminous material shall be either
Rapid Curing (RC) or Emulsified
Asphalt, whichever is called in the
Bill of Quantities. The type and Grade
shall be specified in the Special
Provisions.
 Surface Condition:
Tack Coat shall be applied only to
surfaces which are dry or slightly
moist. No tack coat shall be applied
when the weather is foggy or rainy.
 The tanks shall have a heating device able to
heat a complete charge of bituminous liquid
to 180oC. The heating device shall be such
that overheating will not occur. The liquid
shall be insulated in such a way that the drop
in temperature when the tank is filled
with bituminous liquid at 180oC and not
heated will be less than 2oC per hour.
The distributor shall be designed so that the
deviation from the prescribed rate of application
does not exceed 10% and shall be equipped with a
device for hand spraying of the bituminous liquid
 The rate of application of the
bituminous material shall be within
the range of 0.20 to 0.70 L/m2
 Traffic shall be kept off the tack coat at all times.
The tack coat shall be sprayed only so far in
advance on the surface course as will permit it to
dry to a “tacky condition”.
 Any area that has become fouled by traffic or
otherwise, shall be cleaned and resprayed at the
Contractor’s expenses before the next course is
applied.
 Bituminous Tack Coat shall be
measured by the area covered
in square meter (m2 )
1-Q, Quality Test for every
40 tonnes or 200 drums
 This item includes general
requirements
that
are
applicable to all types of
bituminous plant mix surface
courses
irrespective
of
gradation of aggregate or kind
and amount of bituminous
material.
 Composition and Quality of Bituminous
Mixture
 (Job Mix Formula) The bituminous mixture
shall be composed of aggregate, mineral filler,
hydrated lime and bituminous material
 At least three weeks prior to production,
the Contractor shall submit in writing a jobmix formula for each mixture supported by
laboratory test data along with samples and
sources of the components and viscositytemperature relationships information to the
Engineer for testing and approval.
 Each job-mix formula submitted shall propose
definite single values for:
1. The percentage of aggregate passing each
specified sieve size.
2. The percentage of bituminous material to be
added.
3. The temperature of the mixture delivered on
the road.
4. The kind and percentage of additive to be
used.
5. The kind and percentage of mineral filler to be
used.
 After the job-mix is established, all mixture
furnished for the project shall conform
thereto within the following ranges of
tolerances
Passing No. 4 and larger
sieves
±
7 percent
Passing No. 8 to No. 100
sieves (inclusive)
±
4 percent
Passing No. 200 sieves
±
2 percent
Bituminous Material
±
0.4 percent
Temperature of Mixture
±
10OC
 Should a change in source of material be
proposed or should a job-mix formula prove
unsatisfactory, a new job-mix formula shall
be submitted by the Contractor in writing and be
approved by the Engineer prior to
production
 The
mixture
shall
have
a
minimum
compressive strength of 1.4 MPa.
 The mixture shall have a mass percent air voids
with the range of 3 to 5.
 The mixture shall have an index of retained
strength of not less than 70 when tested by
AASHTO T 165.
A. AGGREGATES
 For every 75 m3/200 t or fraction thereof:
1-G & P, Grading and Plasticity Tests
 For every 1500 m3 or fraction thereof:
1-Q, Quality Test for: (Grading,
Plasticity,
Abrasion, Stripping and Bulk
Specific
Gravity)
1-F, Fractured Face
B. BITUMINOUS MATERIALS
 5.0 to 8.0 mass% of total dry aggregate
 1-Q, Quality Test for each 40 tonnes or
fraction thereof
C. MIX
 For every 75 m3/130 t or fraction thereof:
1-G, Grading Test
1-Ext., Extraction
1-Sty., Stability
1-C, Laboratory compaction
D. HYDRATED LIME
Should be added to the mixture during the mixing
operation in the amount of one-half to one (0.5
to 1.0) mass percent, dry aggregate basis
 For every 100 t or fraction thereof:
1-Q, Quality Test
E. MINERAL FILLER
 For every 75 m3 or fraction
thereof:
1-G & P, Grading and
Plasticity Tests (LL, PL, PI)
Construction Equipment
1. Bituminous Mixing Plant
Sufficient storage space shall be provided for
each size of aggregate.
Plant Scales. Scales shall be accurate to 0.5
percent of the maximum load that may be
required. Scales shall be inspected and sealed
as often as the Engineer may deem necessary
to assure their continued accuracy. The
Contractor shall have on hand not less than ten
20-kg weights for testing the scales
Construction Equipment
2. Hauling Equipment
Trucks used for hauling bituminous mixtures shall
have tight, clean, smooth metal beds which have
been thinly coated with approved material to
prevent the mixture from adhering to the beds.
Each truck shall have a cover of canvass or other
suitable material of such size as to protect the
mixture from the weather.
Truck beds shall be drained prior to loading.
Spreading and Finishing
 The mixture shall be placed at a temperature not less
than 1070C as measured in the truck just prior to
dumping into the spreader.
Compaction
 Rolling shall begin at the sides and proceeds longitudinally
parallel toward the road centerline, each trip overlapping ½
the roller width, gradually progressing to the crown of the
road.
 When paving in echelon or abutting a previously placed
lane, the longitudinal joint should be rolled first followed by
the regular rolling procedure.
Compaction
 On super-elevated curves, the rolling shall begin at the
low side and progress to the high side overlapping of
longitudinal trips parallel to the center line.
 Rolling shall be continued until roller masks are
eliminated and a minimum of 97 mass percent of
the density of the laboratory compacted specimens
prepared in accordance with AASHTO T 166 has been
obtained.
Acceptance, Sampling and Testing
 For each full day’s operation:
D & T (Density and Thickness Tests) – at
least one (1) but
not more than
three (3) samples shall be taken.
 If no core samples were taken during the day’s operation,
core samples shall be taken from the completed pavement
for every 100 L. M. per lane.
 The contractor shall supply and furnish new material to
backfill boreholes left by the samples taken.
Acceptance, Sampling and Testing
 No acceptance and final payment shall be made on
completed asphalt pavement unless core test for thickness
determination is conducted
 The compacted pavement shall have a density equal to or
greater than 97 mass percent of the density of
laboratory specimen. The asphalt pavement represented
by the cores shall not be accepted if the deficiency in
density is more than 2%.
Acceptance, Sampling and Testing
 The compacted pavement shall have a thickness
tolerance of -5 mm. Thickness in excess of the specified
thickness shall not be considered in the pavement of
asphalt pavement.
 The asphalt pavement represented by the core shall not
be accepted if the deficiency in the average thickness is
more than 5 mm. Averaging of the density and
thickness of asphalt cores is not permitted.
Acceptance, Sampling and Testing
 If the deficiency in the core thickness is more
than 5 mm, additional layer may be permitted in
order to meet the designed thickness, however
the minimum additional asphalt overlay thickness
should be dependent on the minimum thickness
capacity of the asphalt paver but it should not
be less than 50 mm and that proper
construction procedures are followed.
Surface Tolerances
 The surface will be checked by the use of a 3-m
straight-edge at sites selected by the Engineer.
The straight-edge will be applied at right angles,
as well as, parallel to the centerline of the
roadbed.
 The variation of the surface from the testing
edge between any two contacts with the surface
shall not exceed 6mm.
 The area to be paid for under this
item shall be the number of
square meters (m2) of asphalt
pavement placed, compacted and
accepted based on the thickness
and densities of the cores taken.
 This item shall consist of constructing a
Bituminous Concrete Surface Course
composed of aggregates, mineral filler
and bituminous material mixed in a
central plant, constructed and laid hot on
the prepared base in accordance with
this Specification and in conformity with
lines, grades, thickness and typical crosssection shown on the Plans.
A. AGGREGATE
 Same as for Item 307
B. BITUMINOUS MATERIALS
 5.0 to 8.0 mass % of total dry
aggregate
C. MIX
 Same as for Item 307
D. HYDRATED LIME
 Same as for Item 307
E. MINERAL FILLER
 Same as for Item 307
F. COMPACTED PAVEMENT
 Same as for Item 307
 The proportion of bituminous materials on the basis
of total dry aggregate shall be from 5.0 to 8.0
mass percent. The exact percentage to be used
shall be fixed by the Engineer in accordance with the
job-mix formula and the other quality control
requirements.
During the mixing operation, one-half to one (0.5 to 1.0) mass
percent of hydrated lime, dry aggregate basis, shall be added to the
mixture. The lower percentage limit is applicable to aggregate which
are predominantly calcareous.
Construction Requirements
 Same as for Item 307
Method of Measurement
 Same as for Item 307
PORTLAND CEMENT
CONCRETE PAVEMENT
This item shall consist of pavement of
Portland Cement Concrete, with or
without reinforcement, constructed on
the prepared base in accordance with
this specification and in conformity with
lines, grades, thickness and typical crosssection shown on the plans
311.2 Material Requirements
311.2.1. PORTLAND CEMENT
It shall conform to the applicable requirements of item
700, Hydraulic Cement (AASHTO M 85 or ASTM C 150)
Only Type 1 Portland Cement shall be used unless
otherwise provided for in the Special Provisions.
Different brands or the same brands from different
mills shall not be mixed nor shall they be used
alternately unless the mix is approved by the
Engineer.
311.2.1. PORTLAND CEMENT
However, the use of Portland Pozzolan Cement
Type 1P meeting the requirements of AASHTO M
240/ASTM C 595 Specifications for Blended
Hydraulic Cement shall be allowed, provided that
trial mixes shall be done and that the mixes
meet the concrete strength requirements, the
AASHTO/ASTM provisions pertinent to the use of
Portland Pozzolan Cement Type 1P shall be
adopted.
311.2.1 PORTLAND CEMENT
Sample of cement shall be obtained in
accordance with AASHTO T 127
One (1) Quality Test for every 2000 bags
or fraction thereof
Quantity of sample: 10 Kg.
311.2.2 FINE AGGREGATE
It shall consist of natural sand, stone screenings
or other inert materials with similar
characteristics, or combinations thereof, having
hard, strong and durable particles.
311.2.2 FINE AGGREGATE
It shall not contain more than three (3) mass percent
of material passing the 0.075 mm (No. 200 sieve) by
washing nor more than one (1) mass percent each of
clay lumps or shale.
If the fine aggregate is subjected to five (5) cycles of
the sodium sulfate soundness test, the weight loss
shall not exceed 10 mass percent.
311.2.2 FINE AGGREGATE
The fine aggregate shall be free from injurious
amounts of organic impurities.
The fine aggregate shall be well-graded from
coarse to fine and shall conform to Table 311.1
311.2.3 Coarse Aggregate
It shall consist of crushed stone, gravel, blast furnace
slag, or other approved inert materials of similar
characteristics, or combinations thereof, having hard,
strong, durable pieces and free from any adherent
coatings.
It shall contain not more than one (1) mass percent
of material passing the 0.075 mm (No. 200) sieve,
not more than 0.25 mass percent of clay lumps, nor
more than 3.5 mass percent of soft fragments.
311.2.3 Coarse Aggregate
If the coarse aggregate is subjected to five (5)
cycles of the sodium sulfate soundness test, the
weighted loss shall not exceed 12 mass percent.
It shall have a mass percent of wear not
exceeding 40 when tested by AASHTO T 96.
If the slag is used, its density shall not be less
than 1120 kg/m³.
311.2.3 Coarse Aggregate
The gradation of the coarse aggregate shall conform to Table 311.2.
311.2.4 Water
Water used in mixing, curing or other designated
application shall be reasonably clean and free of oil,
salt, acid, alkali, grass or other substances injurious to
the finished product.
Water will be tested in accordance with and shall
meet the requirements of Item 714, Water but water
which is drinkable may be used without test.
311.2.5 Reinforcing Steel
It shall conform to the requirements of Item 404, Reinforcing Steel.
Dowels and tie bars shall conform to the requirements of AASHTO M
31 or M 42, except that rail steel shall not be used for tie bars that are
to be bent and re straightened during construction.
Tie bars shall be deformed bars. Dowels shall be plain round bars.
Before delivery to the site of work, one-half of the length of each
dowel shall be painted with one coat of approved lead or tar paint.
Storage of Cement and Aggregate
All cement shall be stored, immediately upon
delivery at the Site, in weatherproof building
which will protect the cement from dampness.
Bulk cement, if used, shall be transferred
to elevated air tight and weatherproof bins.
Stored cement shall meet the test requirements
at any time after storage when retest is ordered
by the Engineer.
Proportioning, Consistency and Strength
of Concrete
The contractor shall prepare the design mix based
on the absolute volume method as outlined in the
American Concrete Institute (ACI) Standard 211.1.
It is the intent of this Specification to require at least
364 kg of cement per cubic meter of concrete
to meet the minimum strength requirements.
Slump shall be determined using AASHTO T 119
Proportioning, Consistency and Strength
of Concrete
Flexural Strength shall determine using AASHTO
T 97 for Third-Point Method and AASHTO T 177
for Mid-Point Method or AASHTO t 24 for
Compressive Strength.
311.3.10 Test Specimens
• As work progresses, at least one (1) set consisting of three (3)
concrete beam test specimens, 150 mm x 150 mm x 525 mm shall
be taken from each 330 m² of pavement, 230 mm depth, or
fraction thereof placed each day.
• Test specimens shall be made under the supervision of the
Engineer, and the Contractor shall provide all concrete and other
facilities necessary in making the test specimens and shall protect
them from damage by construction operations.
• Cylinder samples shall not be used as substitute for determining
the adequacy of the strength of concrete.
311.3.20 Acceptance of Concrete
311.3.22 Tolerance and Pavement thickness
2. Pavement Thickness
In calculating the average thickness of the pavement, individual
measurements which are in excess of the specified thickness
by more than 5 mm will be considered as the specified
thickness plus 5 mm and measurement which are less than the
specified thickness by more than 25 mm shall not be included
in
the
average.
311.3.22 Tolerance and Pavement thickness
3. Adjustment for Thickness
• When the average thickness of the pavement per lot is deficient,
payment for the lot shall be adjusted as follows:
STRUCTURAL
CONCRETE
• This Item shall consist of furnishing, bending, placing
and finishing concrete in all structures except
pavements in accordance with this Specification and
conforming to the lines, grades, and dimensions
shown on the Plans.
• Concrete shall consist of a mixture of Portland
Cement, fine aggregate, coarse aggregate, admixture
when specified, and water mixed in the proportions
specified or approved by the Engineer.
Classes and Uses
of Concrete
Five classes of concrete are provided for in this Item, namely: A, B, C,
P and Seal. Each class shall be used in that part of the structure as
called for on the Plans. The classes of concrete will generally be used
as follows:
• Class A – All superstructures and heavily reinforced substructures.
The important parts of the structure included are slabs, beams,
girders, columns, arch ribs, box culverts, reinforced abutments,
retaining walls, and reinforced footings.
• Class B – Footings, pedestals, massive pier shafts, pipe bedding,
and gravity walls, unreinforced or with only a small amount of
reinforcement.
• Class C – Thin reinforced sections, railings, precast R.C. piles and
cribbing and for filler in steel grid floors.
• Class P – Pre stressed concrete structures and members.
• Seal – Concrete deposited in water.
405.2 Material Requirements
405.2.1 Portland Cement
405.2.2 Fine Aggregates
• It shall conform to all the requirements of
Subsection 311.2.1.
405.2.3 Coarse Aggregate
It shall conform all the requirements of Subsection 311.2.3 except that
gradation shall conform to Table 405.1.
405.2.4 WATER
It shall conform to the requirements of Subsection 311.2.4
405.2.5 REINFORCING STEEL
It shall conform to the requirements of Item 710, Reinforcing Steel
and Wire Rope.
Proportioning and Strength of Structural Concrete
• The strength requirements for each class of concrete shall be as specified in
Table 405.2
405.5 Method of Measurement
The quantity of structural concrete to be paid
for will be the final quantity placed and accepted in
the completed structure. No deduction will be made
for the volume occupied by pipe less than 100mm
(4 inches) in diameter or by reinforcing steel,
anchors, conduits, weep holes or expansion joint
materials.
405.6 Basis of Payment
GROUTED RIPRAP
• This Item shall consist of furnishing
and placing of riprap with or without
grout as the case may be, with or
without filter backing, furnished and
constructed in accordance with this
Specification and to the lines and
grades and dimensions shown on the
Plans.
• Sound pieces of broken
concrete obtained from the
removal of bridges, culverts
and other structures may be
substituted for stone with the
approval of the Engineer.
Stones for riprap shall be one of the following
classes
• Class A – Stones ranging from a minimum of 15kg to a
maximum of 25kg with at with at least 50 percent of the
stones weighing more than 20kg.
• Class B – Stones ranging from minimum of 30 kg to a
maximum of 70 kg with at least 50 percent of the stones
weighing more than 50kg.
• Class C – Stones ranging from minimum of 60 kg to a
maximum of 70 kg with at least 50 percent of the stones
weighing more than 80 kg.
• Class D – Stones ranging from minimum of 100 kg to a
maximum of 200 kg with at least 50 percent of the stones
weighing more than 150 kg.
505.2.2 Filter Materials
• When required, the riprap shall be placed on a filter
layer to prevent fine embankment materials to be
washed out through the voids of the face stones. The
grading of the filter material shall be as specified on the
Plans, or in the Special Provisions. If not so specified, it
will be required that D15 of the filter is at least 4 times
the size D85 for the embankment material, where D15
percent and 85 percent, respectively, passing (by mass)
in a grain size analysis. Fine aggregate passing grading
requirements for Item 405, Structural Concrete, will
satisfy foregoing requirements.
505.2.3 Mortar
• Mortar for grouted riprap shall consist of sand, cement
and water conforming to the requirements given under
Item 405, Structural Concrete, mixed in the proportion
of one part cement to three parts sand by volume, and
sufficient water to obtain the required consistency.
• The horizontal and vertical contact surface between
stones shall be embedded by cement mortar having a
minimum thickness of 20 mm. Sufficient mortar shall
be used to completely fill all voids leaving the face of
the stones exposed.
505.3.2 Placing
• Stones placed below the water line shall be distributed so
that the minimum thickness of the riprap is not less than
that specified.
• Stones above the water line shall be placed by hand or
individually by machines. They shall be laid with close,
broken joints and shall be firmly bedded into the slope and
against the adjoining stones. Each stone shall be laid with its
longest axis perpendicular to the slope in close contact with
each adjacent stone. The riprap shall be thoroughly rammed
into place as construction progresses and the finished
surface shall present an even, tight surface. Interstices
between stones shall be filled with small broken fragments
firmly rammed into place.
505.3.2 Placing
• Unless otherwise provided, riprap shall have the following
minimum thickness, measured perpendicular to the slope:
• Class A – 300 mm
• Class B – 500 mm
• Class C – 600 mm
• Class D – 800 mm
The surface of riprap shall not vary from the theoretical
surface by more than 100 mm at any point.
505.3.3 Grouting
• When grouted riprap is specified, stones shall be placed
by hand, or individually by machine as specified for
riprap placed above the water line. The spaces between
the stones shall then be filled with cement mortar
throughout the thickness of the riprap as specified in
Subsection 504.2.3, mortar. Sufficient mortar shall be
used to completely fill all voids, except that the face
surface of the stones shall be left exposed.
505.3.3 Grouting
• Grout shall be placed from bottom to top of the surface
swept with a stiff broom. After grouting is completed,
the surface shall be cured as specified in Item 405,
Structural Concrete for a period of at least three days.
• The stones shall also be laid in a manner that the
vertical and horizontal alignments of the exposed face
shall, as possible be maintained in a straight line.
505.3.3 WEEPHOLES
• All walls and abutments shall be provided with weepholes.
Unless otherwise shown on the Plans or directed by the
Engineer, the weepholes shall be placed horizontally at the
lowest points where free outlets for water can be obtained
and shall be spaced at not more than 2 m center to center in
a staggered manner . The length of the weepholes shall not
be less than the thickness of the walls of the abutment and
shall be at least 50 mm diameter PVC or other pipe
materials accepted by the Engineer. Weepholes must be
provided with filter bags as specified in special provision or
as directed by the Engineer, and shall be incidental to Pay
Item 505.
505.4 Method of Measurement
• The quantities to be measured for payment shall be the
number of cubic meters of riprap or grouted riprap, as the
case may be, including stones placed in the toe trench laid
in position and accepted.
• Filter layer of granular material, when required, shall be
measured separately by the cubic meter in place and
accepted.
• The computation of the quantities will be based on the
volume within the limiting dimensions designated on the
Plans or as determined by the Engineer.
505.5 Basis of Payment