Ch.4.1.1: FLEXIBLE

PAVEMENT

Pavement is the structure which separates

the tires of vehicles from the underlying

foundation material.

The flexible pavement usually consists of

three main layers, the bituminous surfacing

(wearing & binder course), the base or road

base and the sub base,

For the rigid pavement consists of two

layers, concrete slab and the subbase.

Flexible & Rigid Pavement

ELEMENT OF FLEXIBLE PAVEMENT

The principal element of flexible

pavement include ;

Wearing course

Binder course

Base course

Subbase couse

subgrade

Subgrade

Sub-base

Base

Binder Course

Wearing Course Surface

Formation layer

STRUCTURAL LAYER

ROAD SURFACE

It should be capable of

withstanding high tire pressure,

resisting the abrasive force due

to traffic.

Providing a skid-resistance

driving surface and preventing

the penetration of surface

water depending on the

expected traffic on the

pavement.

7

Top layer with the main function to

the safety of the road users.

The other functions of wearing

course:

Provides smooth & dense riding

surface

Takes up wear & tear due to traffic

Provides water tight

Provides hard surface Drainage system – provide water prove layer

and drain surface run-off to the side drain.

WEARING COURSE

mdyusri@uthm.edu.my 8

This layer is used to spread

the force from the surface and

provide the flat surface to

construct the wearing course.

The maximum size of aggregate

used is ACB 14 or ACB 20 and

percentage of bitumen ranging

from 4 – 6 %. (Jabatan Kerja

Raya 1986).

BINDER COURSE

BASE COURSE

This layer is used to absorb force

from surface and spread the

force to the thickest layer

Base course shall apply selected

materials such as crushed stones

and sand, or a combination of

these materials. It may stabilized

with cement bitumen or lime.

According AASHTO T 96-97 (1982)

Grading A Table 1 of the size

aggregate to be used is 40 mm

mdyusri@uthm.edu.my 10

Sub-base material consist of sand

gravel and laterite

Functions of sub-base: I. Support road base & spreads force

to the sub-grade

II. Prepares the drainage using rough

materials

III. Prepare cover at any layer that is

constructed

IV. Bears the pressure from heavy

vehicles

V. Prevent the sub-grade from traffic

flow

SUB-BASE COURSE

Sub-grade is the part of embankment or

natural soil / filled soil

The surface of sub-grade is identified as

a formation level.

The formation level is the soil surface

after the earthwork, consolidation,

compaction and stabilization works were

completed.

Sub-grade is used as a layer which

sustain load from the top surfaces. mdyusri@uthm.edu.my 11

SUBGRADE COURSE

SUMMARY OF MATERIALS USED IN FP

PAVEMENT

LAYERS

MATERIAL TYPES

Sub-Grade Natural soil / filled soil

Sub-Base Sand gravel /

Laterite /

Selected soil

Base Crusher run (aggregate size 40

mm)

Surface Pre-mix bitumen

Pre-mix concrete asphalt (ACB 14

or ACB 20)

ANNOUNCEMENT

• LECTURE 28 SEPT 2012

• CHANGE TO 2:30 – 4:00 PM

CH.4.1.2. – 4.1.3. :

PREPARATION MATERIALS IN

SUB-BASE (SUB-TAPAK) AND

BASE (TAPAK) FOR FLEXIBLE

PAVEMENT C3010 – HIGHWAY

ENGINEERING

PREPARATION MATERIALS FOR

SUB-BASE (KETAPAK)

Introduction

• Materials used in sub-base layer must

consist of hard stone, high durability

and clean

• Consists of crusher run, gravel, laterite

(batu merah) or sand

• These materials must be freed from

organic content, lump of clay and any

materials that easily spoil

• Below is the BS standard Passing Weight % for crusher run, gravel or laterite materials.

• Other materials can be used but must achieve the CBR value (not less than 20 % after immersed and compacted to 95 % maximum dry density.)

• Materials also must be freed from leaf mass, soft particles or lump of clay.

Table 1.0: Passing Weight % for

Crusher Run, Gravel or Laterite

BS sieve Passing Weight

% (A)

Passing Weight

% (B)

40 mm (1 ½ in) 100 -

28 mm (1.0 in) 75 – 100 100

20 mm (3/4 in) 60 – 90 70 -100

10 mm (3/8 in) 45 – 75 58 – 75

5 mm (3/16 in) 30 – 60 35 – 65

2.4 mm (No. 7) 20 – 50 25 – 50

2.4 mm (No. 36) 10 – 30 15 – 30

75 m (No. 200) 0 – 2 0 - 2

CRUSHER RUN

• Crusher run road base is commonly used

by JKR (PWD)

• Its consist of one type of stone either

limestone or dolomite, and sometimes

granite and were crushed in two stages to

gain good grade and stabilization.

• Below the crusher run grade according to

BS 1377

Table 1.1: B.S. 1377 CRUSHER

RUN GRADE LIMIT

SIEVE B.S PASSING WEIGHT

%

50 mm

40 mm

20 mm

10 mm

5 mm

No. 7

No. 25

No. 200 (non-plasticity

quarry dust)

100

95 – 100

60 – 80

40 – 60

25 – 40

15 – 30

8 – 22

0 - 8

ADVANTAGES &

DISADVANTAGES OF CRUSHER

RUN

ADVANTAGES DISADVANTAGES

Materials easily laid and

leveled

Difficult to separate

between fine and coarse

aggregates

The desire density

(kepadatan) can be

obtained quickly

Materials cost is cheap

SAND

• Two types of sand used for

FP:-

–Dry sand mix (adunan pasir

kering)

–Wet sand mix (adunan pasir

basah)

SAND

• Dry sand mix:

–aggregates & selected sand

(clean sand) – don’t have 5%

clay and not more than 25%

gravel

SAND

• Wet sand mix:

–Sand that consist of 5% moisture

and selected clean sand – more

than 25% gravel and < 2% clay

Table 1.2: Passing Weight % for

Sand

B.S. SIEVE PASSING WEIGHT %

10 mm 100

5 mm 75 – 100

No. 14 45 – 80

No. 52 10 – 30

No. 100 2 - 10

LATERITE

• Late rite for sub-grade layer

• Compacted leveled and be cut to camber as in plan

• Unsuitable soil to be changed with suitable material

• Formation layer thickness is range from 50 – 75mm sand layer or quarry dust and be compacted with 8 – 10 tones compactors

• This job must be done to prevent clay from absorbing into stone layer of sub-base and reduce the shear strength of pavement

PREPARATION MATERIALS FOR

BASE LAYER

Introduction

• Material: crusher run / hard aggregates

• Properties of materials: high durability, clean, no lump of clay particles or organic content

• Achieve the testing requirement in B.S. 1377 for CBR test and Flakiness Index test in B.S. 812.

Method for materials base

construction of base

• 5 types of method used in preparation of materials at Base layer are:-

a. Crusher run road base

b. Dry bound macadam road base

c. Wet bound macadam road base

d. Bituminous bound road base

e. Stabilized soil road base

Dry-bound Macadam Road base

(Macadam Serikat Kering) • Dry bound macadam use two types materials

which were bring separately to site:-

i. Coarse aggregate: 37.5 – 100 mm

ii. Fine aggregate/fine dust: < 5mm

• Coarse aggregate was laid and compacted at the prepared location.

• Any empty gap between aggregates than will be filled with fine aggregate (quarry dust)

• Final layer, fine aggregate will be applied on the surface.

Figure: Roller

Compactor (Large)

Figure: Vibrator

Compactor

Wet bound macadam road base

(Macadam Serikat Basah)

• Method similar as dry bound

macadam but only added spraying

water after laying/compacting the

coarse aggregate

• Two reasons for spraying water:-

– Act as lubricants

– Moisture make dust to be bound

together

Figure: Bitumen Macadam Plant

Bituminous Bound Road Base

(Tapak Bercampuran Pengikat)

• Graded aggregates were mixed

with tar or bitumen

• Mixture is made at the mixer

before lay

• This method of construction is

costly, but the strength is

higher

Stabilized Soil Road Base

(Tapak Tanah Stabil)

• Soil be stabilized by mechanically

or with stabilize agent

• Mechanical stabilizer: using

compactor machine

• Stabilize agent: using cement,

lime or lime cement

CONSTRUCTION OF SUB-BASE,

BASE, SURFACE LAYER

a. Construction of SUB-BASE

• Sub-base constructed in 2 layers

(if the thickness is more then 150

mm)

• Every layer must be compacted

carefully with compactor

machine

• Compactors with rubber roller can

compact 120 mm layer in 12

times

a. Construction of SUB-BASE

• Compacting should start from the side

of the road then slowly towards the

middle of the road in horizontal way

• In super-elevated (sendeng) bends,

compaction machine will start at the

lowest part and slowly towards the

higher level.

• Finished part not be more than 20 mm

from the plan

b. Construction of BASE-

COURSE • Base material constructed with crusher run.

• Before road base is constructed, sub-grade

& sub-base surface MUST BE FORMED

PERFECTLY and COMPACTED enough

• Base must be constructed in 2 layers of

same thickness.

• Each layer should not exceed 150 mm

c. Construction of ROAD

SURFACE • Road surface constructed with bitumen

materials

• Materials: Concrete Asphalt, macadam

bitumen and tar

• Construction should free from dust and

waterproof

• Prime coat is poured onto road base

surface as a binder between road base and

base course (binder layer)

c. Construction of ROAD

SURFACE • Base course is built on one layer only

with paver’s machine, and later will be

compacted.

• Compacting must be done immediately

• Compacted should be started from the

side towards to the middle of the road

• Compacted at super elevated, from

lower to higher part

Paver Machine

CH.4.1.10:

Test to be carried out to

ensure the quality of the sub-

base & sub-road layer

SUB-GRADE

LAYER OF

PAVEMENT

TYPE OF TESTING TO BE

CARRIED OUT

Embankment,

fill / backfill &

select

fill/backfill

•Determination of ATTERBERG LIMITS

(Had alterberg), SWELLING or

SHRINKAGE CHARACTERISTIC (ciri-ciri

pengembangan atau pengecutan)

•Determination of PLASTICITY INDEX

(Indek keplastikan)

•GRADATION ANAYSIS of material

(Analisis Pengredan Bahan)

LOWER SUB-BASE & TOP 300

MM SUB-GRADE

LAYER OF

PAVEMENT

TYPE OF TESTING TO BE

CARRIED OUT

Lower Sub-

base and top

300 mm of

sub-grade

•ATTERBERG LIMITS

•PLASTICITY INDEX

•GRADATION ANALYSIS

•B.S. 1377 COMPACTION TEST (4.5 kg

rammer method)

•CBR test (4 day soak with surcharge and

swell measurement)

Earth

Shoulders

•Same as lower sub-base

SUB-BASE & ROAD BASE

LAYER OF

PAVEMENT

TYPE OF TESTING TO BE CARRIED

OUT

Sub-base and

Road base

(gravel

shoulders, gravel

surfacing,

crushed

aggregate)

•ATTERBERG LIMITS

•PLASTICITY INDX

•GRADATION ANALYSIS

•B.S. 1377 COMPACTION TEST (4.5 kg

rammer method)

•CBR test (4 day soak with surcharge and

swell measurement)

•Determination of FLAKINESS INDEX

•Determination of % PARTICLES with a

fractured face

SUB-BASE & ROAD BASE

LAYER OF

PAVEMENT

TYPE OF TESTING TO BE CARRIED

OUT

Sub-base &

Road base

(Quality

materials)

Same as above

Additional

Sodium sulphate soundness test

Aggregate crushing value test

Sub-base &

Road base

(cement or lime

stabilization of

soils or

aggregates)

Same as above

CBR test (as specified)

Compressive strength test (soil cement)

Wetting and drying test (soil cement)

BITUMINOUS SURFACE LAYER OF

PAVEMENT

TYPE OF TESTING TO BE CARRIED

OUT

Bituminous surface

(Aggregates and

penetration

Macadam)

•GRADATION ANALYSIS

•FLAKINESS INDEX, % of elongated

particles

•Determination of % PARTICLES with a

fractured face

Additional tests:

•SPECIFIC GRAVITY and

ABSORPTION test

•Sodium sulphate SOUNDNESS TEST

•AGGREGATE CRUSHING VALUE

TEST

•POLISHED STONE VALUE TEST

•BITUMEN STRIPPING TEST

BITUMINOUS SURFACE

LAYER OF

PAVEMENT

TYPE OF TESTING TO BE

CARRIED OUT

Bituminous Surface

(Aggregates for

Bituminous

Macadam and

Bituminous

Macadam Mixtures)

•Same as above

Additional tests:

•COMPREHENSIVE MARSHALL

Method test

Bituminous Surface

((Aggregates for

Asphaltic concrete

and Asphaltic

Concrete Mixture)

•Sodium sulphate SOUNDNESS TEST

•AGGREGATE CRUSHING VALUE TEST

•POLISHED STONE VALUE TEST

•BITUMEN STRIPPING TEST

Priming Work (Penyebuan)

Priming Work (Penyebuan)

• Priming (Penyebuan)

– Definition: The application of primer

pavement (salut turapan)

• Two types of priming work are:-

– Primer-binder (salut jelujur)

– Primer-sealing (salut perdana)

PRIMER BINDER (SALUT

JELUJUR) • Definition:

– A field or refinery cutback bitumen used, with a cover of aggregate, to provide surface penetration (preferably from 2 mm to 5 mm) and a trafficable wearing surface.

• Materials used: Asphalt cutback types RC -70, PK-3 or AK-3

• Application method: using spray

• Amount spray : 0.2 – 0.5 liter/m2

• Method spraying: spray bit by bit and uniform so as not to produce semi-thick coating of asphalt will cause problems asphalt surface layer