1

PAVEMENT INSPECTION, CONDITION

SURVEY AND DATA COLLECTION

BY

Dr. Devesh Tiwari

Scientist

CENTRAL ROAD RESEARCH INSTITUTE

NEW DELHI

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Road Inventory • Terrain (P/R/H)

• Land use

• Name of Village

• Formation Width

• Carriageway • Type

• Width

• Condition

• Shoulder • Type

• Width

• Condition

• Embankment height

• Submergence

• Details of Cross roads

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PAVEMENT CONDITON ASSESSMENT THROUGH VISUAL

INSPECTION

• General Information of Road Features

• Determination of level of existing distress

• Decisions based on engineering experience

• Final Strategy

METHODOLOGY FOR VISUAL INSPECTION

• Walk survey- associated with or without actual measurement

Divide pavement area into rectangular blocks for assessment

Human Rating

• Drive survey

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Sl.

No.

Important Features

1 Total Length (km.)

2 Carriageway Width (m) with lane details

3 Paved Shoulders (m)

4 Earthen Shoulders (m)

5 Median Width (m)

6 Pavement Composition

Bituminous Concrete (BC) / AC

Dense Bituminous Macadam (DBM)

Wet Mix Macadam (WMM)

Granular Sub-base (GSB) / Stabilised Subbase

Subgrade / Improved Subgrade

7 Service Road Length / Width

8 Major Bridges

9 Minor Bridges

10 Culverts

RCC (Slab / Box)

Hume Pipes

11 Road Side Furniture

IMPORTANT ENGINEERING FEATURES OF THE PROJECT

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Pavement Condition Survey

• Pavement composition

• Shoulder

• Riding Quality

• Pavement Condition

• Cracking

• Ravelling

• Potholing

• Rut

• Patching

• Road side drain

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EVALUATION OF PAVEMENTS

• Increase in traffic volume and axle load

• Highways becomes structurally / functionally

inadequate for the existing subgrade and traffic

conditions

• Leads to fast rate of deterioration

- Most of the pavements shows significant distress

• Need for structural/functional evaluation

FUNCTIONAL EVALUATION AND

STRUCTURAL EVALUATION

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FUNCTIONAL REQUIREMENT OF PAVEMENTS

• Provide safety

- Have sufficient friction to avoid skidding

• Comfort

- Provide comfortable ride at a design speed

• Fast movement of traffic with minimum vehicle operation cost

(VOC) not have excessive surface distress

PAVEMENT DISTRESS

• Pavement distress is a relative term and has direct relation to

the function for which a facility has been provided.

• The pavement which may be regarded as good for slow

moving vehicles, may be considered as distressed for high

speed traffic.

• It can also be defined as `physical manifestation of internal

damage caused which may be due to inadequacy of structural

or functional system.

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Types of Distress

The major types of distress that occur indicating deterioration of

flexible pavements are:

• Load-associated cracking/fatigue cracking

• Load associated permanent deformation/rutting/ roughness

• Low temperature shrinkage cracking

• Non-load associated distortion such as differential settlement of

foundations, frost heave etc.

• Non-load associated cracking due to swelling and shrinkage

movements in foundations

• Disintegration in the form of potholes, stripping, ravelling, spalling

etc.

• Reflection cracking

• Interaction of combination of above distresses

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Cracking

• Hair line cracking

• Crocodile cracks (Interconnected Polygons)

• Longitudinal cracks (Line cracks longitudinally along

pavement)

• Transverse cracks (Line cracks transverse across

pavement)

• Irregular cracks (Unconnected cracks without any distinct

pattern)

• Map cracks (Interconnected Polygons)

• Block cracks (Interconnected line cracks in rectangular

pattern)

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Cracks Longitudinal

Transverse

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WIDE MAP

CRACKING

SEVERE FATIGUE CRACKS

WITH PERMANENT

DEFORMATIONS

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Cracks

BLOCK CRACKS

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Main Causes

poor quality materials,

poor workmanship,

insufficient pavement thickness

shrinkage

pavement age

Remedies

Surface Cracking: Local Sealing or Filling in of the

Cracks

Cracks in the pavement structure: Local Sealing or

Patching

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Disintegration

• Ravelling (Loss of stone particles from surface)

• Pot holes (Open cavity in surface, at least 150 mm dia.

and at least 25 mm depth)

• Edge break (Loss of fragments at edge of surface)

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POTHOLES

Location: No Particular Location but sometimes

close to cracks, to areas of shoving or fatting up

16 EXTENSIVE PATCH WORK AND WIDE CRACKING

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Main Causes

• poor quality of material used for the construction

• infiltration of water

• break away of material under the action of traffic

and

• final stage in the development of a depression.

Remedies

• local restoration of the pavement structure.

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EDGE DAMAGE Location

Along the edges of the

pavement.

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Main Causes

• wear of the shoulder (formation of step),

• action of water,

• insufficient compaction of the edges

• road too narrow.

Development, if neglected

• rapid during the rainy season.

Remedies

• local restoration of the pavement structure

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Surface Deformation

• Rut (Longitudinal depression in wheel paths)

• Depression (Bowl shape depression in surface)

• Mound (Localized rise in surfacing)

• Ridge (Longitudinal rise in surface)

• Corrugation (Transverse depression at close

spacing)

• Undulation (Transverse depression at long spacing)

• Roughness (Irregularity of pavement surface in

wheel paths)

• Shoving

21 LOCALISED DEPRESSION

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Main Causes

• insufficient pavement strength

• inadequate stability of the bituminous surfacing

• if water is able to penetrate into pavement

Remedies

rutting<= 2 cm: filling in of the ruts and depressions,

rutting> 2 cm: local restoration of the pavement

structure.

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SHOVING

Location

• Usually on either side of the

wheel tracks

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Location

Part or the whole of the road surface.

Main causes too much binder

unsuitable binder

Remedies - sanding

- surface dressing

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Surface Defects

• Bleeding

• Polished aggregate

• Ravelling and Weathering

• Stripping

• Hungry surface

Miscellaneous Distresses

• Lane to shoulder drop off

• Lane shoulder separation

• Water bleeding and pumping

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BLEEDING

27 SURFACE SHOWING BLEEDING

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Main Causes

• materials of poor quality,

• insufficient compaction,

• traffic

Remedies

Small irregularities:

• filling in of irregularities,

Large irregularities together with cracks

• local restoration of the pavement surface

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FACTORS RESPONSIBLE FOR PAVEMENT

DISTRESS

•Structural Adequacy

•Material Characteristics

•Traffic Volume and Axle Loads

•Subgrade Support

level of compaction

moisture content and

drainage conditions

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• Climatic Conditions

-Rainfall causes moisture variation in subgrade and pavement layers. If

the subgrade has clayey soil of high plasticity Index, it causes

considerable variation in the stability and structural condition of the

pavements.

-Temperature variation affects the stiffness of bituminous layers

becoming soft under high temperature and stiff in low temperature.

- Extreme weather conditions cause early deterioration of the pavement.

• Environmental Conditions

Water enters the pavement from three sides-

- From top through cracks and other types of distress,

- From sides through shoulders if not properly maintained and

compacted and

- From bottom by capillary a action

Environmental conditions - height of embankment or depth of cutting,

terrain conditions, gradient, depth of water table are responsible for

controlling moisture movement. These conditions are responsible for

development of distress and overall performance of the pavement.

• Quality Control

• Maintenance Inputs

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FUNCTIONAL EVALUATION ( PAVEMENT SURFACE CONDITION)

• Skid Resistance

Surface Type

- Pavement surface type (WBM, bituminous surface, cement

concrete)

- Surface finish

- Properties of mix (open graded/dense graded)

- Bitumen content

- Aggregate type (micro texture, aggregate polishing value,

shape)

Pavement Surface Condition

Speed

Tyre Characteristics

- Treaded or smoothened,

- Tyre pressure and

- Load coming on the tyre particularly on wet surface

Other Factors

- Temperature

- Age of pavement

- Construction and maintenance practices

- Traffic and its smoothening effect on the pavement surface

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Methods of Measuring Skid Resistance

Stopping Distance Method

- Developed at CRRI

- Jeep fitted with device for commencement of braking

- The vehicle run at 40 km/hr and wheels are locked by applying brakes

on the wet surface

- Distance travelled point to the points

- Distance travelled and speed stopping distance Number (SDN) found

British Pendulum Tester (BPT)

- Developed by TRRL, UK - portable dynamic pendulum type tester

- Simple device used in the field and laboratory

- Consists pendulum with a spring loaded rubber shoe attached

- Pendulum is dropped and shoe slides on the surface to be tested

- Extent to which the shoe rises is read on the graduated scale

- Results are presented as British Pendulum Number (BPN)

- Skid resistance measurements obtained with this equipment

correspond to performance of a patterned type of a car braking with a

locked wheel on a wet road running at 50 km/hr

- Result it is being widely used

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Mu-Meter, SCRIM

• Developed by TRRL UK for measuring side coefficient of friction

• Consists of test wheel fitted as a fifth wheel to a test vehicle at

20o to the direction of travel

• Smooth tread type tyre is used for getting the result under

worst condition

• Measurement is normally made at a standard speed of 64 km/hr

• Continuously records the Mu value (sideway force coefficient)

versus distance travelled along the pavement

• Equipment provided with water tank and data printing unit

• Data can be obtained upto 100 kmph from the data printing unit

• Advantages over the other units.

• Test can be conducted conveniently and quickly

• Data can be recorded continuously

• Tyre wears uniformly

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Skid Trailer

•Developed in USA - measures the locked wheel

friction between the tyre of standard design, size

and inflation pressure and wet road surface when

the vehicle is run at constant speed of 64 km/hr.

•Skid resistance is calculated as the ratio of frictional

resistance to normal load

•Result is expressed as skid number (SN) and

measurement is discontinuous with high output

• The locked wheel test method corresponds to the

emergency stopping of vehicle

•Results are electronically recorded and print out is

obtained

• Tests are conducted only on straight sections

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Pavement Unevenness

Serviceability of a pavement is a function of its unevenness

Uneven roads cause increase in cost due to :

- Increase in vehicle operation cost

- Increase in travel time resulting in increase in cost of

vehicle and time of passengers

- Increase in intangible costs such as early fatigue of

drivers, discomfort to passengers.

- Higher accident rates

Methods of Evaluation of Unevenness The evaluation of undulations/unevenness in pavements

may be divided into two broad classifications

• Methods which are based on certain physical

measurement of the surface undulations

• Methods which are based on human response to surface

undulations during riding

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Methods based on Physical Measurement of

Surface Unevenness

• Spot levels

• Straight Edge

• Unevenness Indicator

• Pofilograph

• Bump Integrator

• Dipstick

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Spot Level

• Old method, very slow and tedious method with interpretation for

common pavement undulation is difficult

• Measured using leveling instrument & leveling staff along the desired

line on the pavement surface at known distance intervals

• These levels are with respect to some bench mark with datum line at fixed

level

• Undulations noted are absolute values with reference to fixed datum and

he actual surface profile of the pavement could be plotted

Straight Edge

• Very slow and cumbersome method

• Straight edge (usually 3m in length and in some cases, 4.5m) placed on

the pavement surface which rest on the highest spots or humps

• The depression below the straight edge are measured with

graduated wedge or steel scale

• Depressions are then grouped into different ranges such as 6 to 8, 10

to 12 etc.

• With the help of straight edge longitudinal and cross profile can be

plotted

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Unevenness Indicator

• Developed at CRRI and has a moving datum resting on two sets of

datum wheels 3.0m apart

• Probe wheel is placed in between the datum wheels moves up

and down relative to the temporary datum

• Vertical movement of probe wheel can be measured with pointer

on calibrated dial

• Undulation more than the specified limit, will be indicated by

pointer on the dial followed by sound of bugger and spray of

paint at the point of higher undulation

• Good tool for quality control checks during construction and for

patch repair

• Has limitation of moving datum mounted on two sets of datum

wheel causes frequent change of datum or reference line

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Unevenness

Indicator

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Profilograph

• Developed at CRRI is also mounted on two sets of datum

wheel 3 m apart

• Probe wheel placed in between the datum wheel move up

and down relative to the temporary datum

• Vertical movement of problem wheel is recorded graphically

indicating the undulations relative to the datum

• Graph moves forward as the instrument moves and the

horizontal scale of 1/200 is obtained

• Useful instrument for evaluating the unevenness of the

pavement surface.

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Profilograph

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Bump Integrator

• Single wheel trailer supported in a heavy chassis by

two single leaf springs on ball bearing shackles

• Vertical movement is damped by two large dashpots

• Unit is towed on the back side of jeep which runs at

a speed of 321 kmph

• Unidirectional vertical movement of the wheel with

respect to chassis are totalized by an integrator unit

and is recorded in inches / cms. by electromagnetic

counters

• Distance travelled by vehicle is measured by

recording wheel revolutions by another counter

located in the vehicle

• The profile of the pavement surface can also

recorded on the graph

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S.

No

.

Type of Surface Condition of Road Surface

Good Average Poor

1 Surface Dressing <3500 3500 – 4500 >4500

2 Open Graded Premix

Carpet

<3000 3000 – 4000 >4000

3 Mix Seal Surfacing <3000 3000 – 4000 >4000

4 Semi-Dense Bituminous

Concrete

<2500 2500 – 3500 >3500

5 Bituminous Concrete <2000 2000 – 3000 >3000

6 Cement concrete <2200 2200 - 3000 >3000

IRI = 0.0032 (BI)0.89

BI = 630 (IRI)1.12

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Dipstick

• Fully integrated data collection and processing system

• Measures, records and analyze road profile accurately and

quickly through computer

• Road face software included to calculate and bring various

profile statistics including International Roughness Index

(IRI)

• Dipstick Profile stands on two support legs

• Two digital displays show the elevations difference between

the Dipstick's two support legs

• Each elevation difference reading are measured

automatically recorded

• Audio and visual signals alert the operator when each

measurement is completed

• Equipment used to calibrate Response Type Roughness

Measuring Equipment

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Method Based on Human Rating Technique

• Trained team consisting of 2-3 persons rate the pavement serviceability by

walking or driving on a good vehicle at a slow speed

• The rating is done based on subjective judgment of rating panel in a five point

or ten point scale

• Average of rating value of three persons is taken and correlated with the

evaluation of actual physical measurements of pavement surface

• Assessment of Functional Requirement

Physical Measurements

• Unevenness Index along the wheel path

• Rut depth

• Percentage cracking

• Percentage of patch area

Present Serviceability Rating (PSR)

• Obtained by a rating panel (2-3 persons) on a five point or ten point scale

after classifying qualitative rating as very poor, poor, fair, good and very good

Present Serviceability Index (PSI)

• Subjective method of pavement surface condition whereas unevenness index

measure is an objective method of measurement

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TOOLS FOR ANALYSES OF

PAVEMENT

•Economic Analysis

•Analysis of Pavement After Faster Data

Acquisition Systems

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Highway Development And Management System (HDM-4)

• Pavement management systems have improved significantly due

to the advances in computer technologies

• Highway administrators have a series of tools or mechanisms that

allow them to make a better use of the available resources for the

maintenance and rehabilitation of the highway pavements.

• Most of the tools are lacking in universal acceptance and

implementation.

• One of the most useful, internationally recognized tools available

for pavement management analysis is the Highway Development

and Management System (HDM-4).

• The HDM-4 system can be implemented to assist the highway

agencies for establishing realistic levels of funding, and to set

levels and priorities to maximize the effectiveness of expenditure

on pavement maintenance activities.

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Input Data

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Collection of Inventory Data

Road Condition Survey (Equipments)

• ARAN

• ROMDAS (ROad Measurement Data Acquisition

System)

• Road Survey Vehicle (RSV) of ARRB

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ROMDAS

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• Roughness

• Pavement Condition Rating

• Road Side Inventory

• Transverse Profile and Rut Depth

• Travel Time

• Video

• GPS

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STRUCTURAL EVALUATION OF FLEXIBLE

PAVEMENT

The structural requirement

of the flexible pavement

are :

• The total thickness of the

pavement and the

thickness of individual

layers should be such

that they are not

subjected to stresses or

strains exceeding the

allowable values

• The pavement layers

should be able to

withstand repeated

applications of wheel

loads of different

magnitudes without

causing excessive

distress / deformation

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Empirical comparison of measured behaviour,

such as deflection to allowable deflections

estimated from performance data

Comparison of measured behaviour against

calculated allowable critical stresses derived

from elastic layer analysis

Using an existing design method to estimate

remaining life or load carrying capacity with

measured behaviour as an input

Combination methods using laboratory test

results in conjunction with theoretical analysis to

get a limiting criteria

EVALUATION APPROACHES

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REQUIREMENTS FOR EVALUATION

Technical Data for PMMS

PMMS Provides Information for Priorities,

Budget and Strengthening Requirements

Evaluation Methods should be Simple,

Reliable, Accurate, Quick and Cheap

Structural Evaluation may be Classified in to

two Groups :

Destructive Testing

Non-Destructive Testing

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Test pit Observations

Cutting of Cores of Bituminous Layers

DESTRUCTIVE TEST

REQUIREMENTS FOR INSITU

MATERIAL COLLECTION

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EVALUATION THROUGH TEST PIT (DESTRUCTIVE

METHOD)

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EVALUATION OF IN-SITU PAVEMENT MATERIALS

IN THE LABORATORY

The following tests are to be conducted for subgrade

and subbase materials :

Atterberg Limits as per IS : 2720-Part-V

Proctor Density / Modified AASHTO Density and

Optimum Moisture Content as per IS : 2720-Part-VII &

IS : 2720 – Part- VIII respectively.

Soaked CBR values at field density and field moisture

as per IS : 2720-Part-XVI

Mechanical Analysis of subgrade soil and subbase

materials as per IS : 2720-Part-IV.

Contd.

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EVALUATION OF IN-SITU PAVEMENT

MATERIALS IN THE LABORATORY Contd.

The following tests are to be conducted for Wet

Mix Macadam and Water Bound Macadam

materials :

Atterberg Limits of fine materials as per IS :

2720 – Part-V

Aggregate Impact Value (%) as per IS : 2386 –

Part - IV

Water Absorption (%) as per IS : 2386 – Part –

III

Combined Flakiness and Elongation Indices

as per IS : 2386 – Part – I

Assessment of filler quantity

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In case the subbase is stabilised, the percentage of stabilised

agent is found out by a standard procedure.

THE FOLLOWING TESTS ARE TO BE CONDUCTED FOR SAMPLES

OFBITUMINOUS MATERIALS COLLECTED FROM TEST PITS AND ON CORE

SPECIMEN :

Binder content using Cold Extraction method as per

ASTM D –2172 and its recovery by Abson method as

per ASTM D – 1865.

Gradation analysis of washed aggregate for

compliance of BC, DBM, SDBC, and BM grading as

the case may be.

Bulk density, Stability and Flow values of core

samples for DBM, SDBC and BC etc. as per ASTM D-

1539 as the case may be.

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Tests to be conducted on

Bituminous Materials contd.

Determination of chemicals composition of recovered bitumen as per ASTM D – 4124.

Determination of Penetration value, Softening point and Ductility as per IS : 1203, IS : 1205 and IS : 1203 respectively.

Impact Value and Water Absorption test on washed aggregate as per IS : 2386 Part-IV and IS : 2386 Part – III respectively.

Stripping value test and Coating test on washed aggregates as per AASHTO T-182-84 procedure

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NON - DESTRUCTIVE TEST

DEFLECTION METHODS IN STRUCTURAL

EVALUATION

Static devices which measure the pavement’s

response to a static load or a single application of

slow moving load. For example Benkelman Beam

and Curvature Meter

Vibratory devices which measures the pavement

response to a vibratory or cylic load. For example

Dynaflect and Road Rater

Impulsive devices which load the pavement by

dropping a known mass through a known distances

and measuring the response of the pavement. For

example, Falling Weight Deflectometer (FWD),

Loadman.

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BENKELMAN BEAM REBOUND DEFLECTION

METHOD FOR EVALUATION FLEXIBLE

PAVEMENTS (NON DESTRUCTIVE)

AC Benkelman : 1953

Widely Used all over the World

In India Widely Used for more than two

Decades

First Guidelines was Drafted as IRC : 81-

1981

Revised as IRC : 81-1997

87 SCHEMATIC DIAGRAM OF BENKELMAN BEAM

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STATIC OR SLOW MOVING DEFLECTION EQUIPMENT

• Measurement of Pavement Surface Deflections under Static or

Slow Moving Loads

• Benkelman Beam

• Widely used Device for the Evaluation/Overlay Design for Flexible

Pavements

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COMPUTATION OF DESIGN TRAFFIC

365 * A [ (1+r)X – 1 ]

NS = --------------------------------------- * F

r

NS = The cumulative number of standard axles for the design

A = Initial Traffic, in the year of completion of construction,

in terms of number of CVPD modified for lane distribution

r = Annual growth rate of commercial traffic

x = Design life in years

F = Vehicle damage factor

90

Single lane road (3.75 m)

Total number of CVPD in both direction multiplied by two

Two lane single carriage way roads

75 percent of the total CVPD in both directions

Four lane single carriage way roads

40 percent of the total CVPD in both directions

Dual carriage way roads

The design of dual two lane carriage way roads should be

based on 75 percent of the number of commercial vehicles

in each direction. The distribution factor shall be reduced by

20 percent for each additional lane

LANE DISTRIBUTION OF COMMERCIAL

TRAFFIC

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VEHICLE DAMAGE FACTOR

Initial traffic

intensity in terms

of number of

CVPD

Terrain

Rolling Plain Hilly

0-150 1.5 0.5

150-1500 3.5 1.5

More than 1500 4.5 2.5

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STATIC WEIGH BRIDGE

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WEIGH IN MOTION SYSTEM

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Factory calibrated geophones are used to

register peak deflections

The operating sequence is completely

automated

Pulse loads between 1500 to 2700 lb (7 to

120 kN) are produced with the model 8000

FWD

Optimum features available with various

Dynatest FWD model include automated

pavement temperature sensing and

automated air temperature sensing

FALLING WEIGHT DEFLECTOMETER

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The Loadman is a portable pavement testing devices

derived from the FWD

The structure of the instrument consists of an aluminum

tube containing a free moving weight

A circular plate at the bottom of the tube is used as loading

surface

The equipment is operated by placing its base on the

surface of the pavement layer and then activating the

electronics which drop the weight and record all relevant

data

The results give deflection and a mean modulus which is a

measure of elastic modulus

The Loadman is reported to give good results specially for

unbound surfaces and thin bituminous layers

LOADMAN

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Latest Equipments

AUTOMATED ROAD SURVEY SYSTEM

(ARSS)

Network Survey Vehicle

5 Point Rut Measurement

Gipsitrac Road Geometry •Distance pulse inputs to measure

distance travelled, speed and

acceleration

•An accelerometer to obtain grade

measurements

•An accelerometer to obtain cross

slope measurements

•Gyroscopes (gyro) to measure

changes in direction

Asset Camera Positions

Trimble GPS Pathfinder Power

Operator’s Console and Display

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ROUGHOMETER-II

•High speed device for

measuring pavement surface

roughness.

•Portable type equipment

•Consists of a small

accelerometer (sensor) device

installed at the rear axle of

survey vehicle,

•Distance measuring instrument

•Interface module and a

controller.

•Speed in between 40 to 60

km/hr,

•Output in IRI

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WALKING PROFILER

• Precision instrument designed to

collect surface profile data

• Accurately assess the

characteristics and quality of any

continuous paved surface.

• Operate at a moderate and

steady walking pace in a straight

line

• Has Integral Control Unit which

provides all the functions of

instrument calibration, survey

setup and operator feedback.

• Directly gives International

Roughness Index in m/km.

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THANK

YOU