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HANDBOOK:CFQUALITYC O N T R O L FO R

C O N ST R UC T I O NO F ROADS ANDR U N W A Y S

(&!cosutRev4ioaj

N ew Delhi

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Indian Roads CongressSpecial Publication 11

HANDBOOK OF

QUALITYCONTROL FORCONSTRUCTIONOF ROADS AND

RUNWAYS

(SecondRevision)

Published by:The Indian Roads Congress.

Copies can be hadfrom

the Secretary, Indian RoadsCongress.JamnagarHouse, ShahjahanRoad,

NewDelhi.11O 011

N EW DELHI Price: Rs.1 60/-(Plus packing & Postage)

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SP: 111988

First Published in July, 1973First Revision : December, 1977Reprinted : October, 1983Second Revision : April, 1984

Reprinted : September, 1989

Reprinted E January, 1994Reprinted: January, 1997

Scplcinbci. 2t)(U)

(The Rights of Publication and Translationare reserved)

Printed at NUTAN PRINTERS. New Delhi-I 10020(1000 Copies)

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Introduction

CHAPTERI

CHA PTER2

CHAPTER3

CHAPTER4

CHAPTER5

CHAPTER6

CHAPTER7

CHAPTER 8

General

Earthwork

Sub-base Courses

Base Courses

Bituminous Surface Courses

Concrete Pavements

Control ofAlignment, Profile and

Surface Evenness

3

13

23

- -. 39

- -. 53

65

- -. 75

Statistical Approach to Quality Control...

APPENDICES

- List ofStandards/Specifications ofIndianRoads Congress referred to in the text

2. List oftest standards of Bureau ofIndian

Standards and other bodies referred to in the text

3. Range ofequipment required for a testingand central, regional and field laboratories

4. Sample forms for quality tests5 Procedure for certain field control tests

not covered by published standards

6. Procedure for checking surface regularityusing a straight-edge

Contents

Page

85

97

98

~.100

112

125

128

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INTRODUCTION

Quality control ofconstruction materials and product is anessential requirements for obtaining imprved and uniform standard

of.roads. Towards this end, a three-day Symposium on QualityControl in the Construction ofRoads and Runways, w as organisedunder the joint auspices of the Indian Roads Congress and the

Central Road Research Institute in New belhi from 27th to29th February, 1968. At the concluding Session ofthis Symposium,the following resolutions were adopted

(1) that quality control ofmaterials and the end product togetherwithprocess involved should form an integral part of constructionspecifications of road and runway projects, and that materials

survey be carried out for each project at the rough estimatestage;

(2) that wherever necessary, the existing specifications be reviewed soas to be realistic and to provide for adequate quality controlmeasures fairto all concerned;

(3) thatadequate financial outlay be provided in the form of either a

basic budgetary provision or as a percentage of each projectestimate to meet the expenses ofquality control;

(4) that a Committee ofexperts be set up to prepare a handbook givingall the details of quality control code and that the handbook be

reviewed periodically based on experience gained;

(5) that short term training programmes be organised to provide the

requisite trained personnel for quality control.

In pursuance ofResolution No. 4, a Committee consisting ofthe following members w as constituted for drafting the Handbook:

(1) Shri S.N. Sinha Cornenor(2) Shri M.K. Chatterjee Member(3) Shri J. Datt(4) Dr. M.P. Dhir I(5) Dr. R.K. Ghosh

(6) Shri T.K. Natarajan(7) Dr. M.L. Purl(8) Shri R.P. Sikka(9) Dr. Bh. Subbaraju

(10) Prof. C.G. Swaminathan(11) Dr. H.L. Uppal

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Introducti

The above Committee, in turn, constituted four Subcomtees to prepare drafts of various Sections. Later, the Commitdecided that, before finalising the Handbook, its main tentatrecommendations regarding the quantum oftesting, control teacceptable tolerances and method of interpretation ofresults, isummarised form, be placed before the National SeminarRoads and Bridges at Bombay in October, 1968 for wider disc

sion. For this purpose, a Working Group consistingDr. M.L. Purl, Dr. M.P. Dhir and Shri R.P. Sikka was entrus

with responsibility of preparing the required summary for circ

tion to the delegates attending the National Seminar.

The Recommendations of the National Seminar w

discussed by the Committee and in light of the discussions, a dring Subcommittee comprising Prof. C.G. SwaminathShri T.K. Natarajan and Dr. M.L. Pun was formed to complthe draft.

The draft prepared by the Subcommittee was discussedthe Committee in a series of meetings and a Working Groconsisting ofShri R.P. Sikka, Dr. M.P. Dhir and Dr. M.L. Pprocessed the same. It was then considered by the ExecutCommittee ofthe Indian Roads Congress, in its meeting heldGandhinagar on 25.11-72. Thereafter, the Council ofthe IndiRoads Congress at its meeting held at Gandhinagar on the sa

day finally approved the draft ofthis Handbook ofQuality Contfor being published as a Special Publication ofthe Indian RoCongress.

The Manual was revised in 1977 (First Revision) to incorrate the new standards on surface evenness approved by the I.R.Council at its Meeting held in Madras on 28.8.76. The secorevision includes the prescribed equipment fo r different labotories and the forms to be used for recording the resultsobservation/test results by the field officers.

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General

1

General

1

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CHAPTER 1

GENERAL

1.1. Need for Quality Control

1.1.1. Quality control is an essential part ofany productionprocess and highway constructions are no exception. Qualitycontrol is an important requirement for highway construction forensuring quality and for creating durable national assets. Theneed for quality control on these constructions has increased con-

siderably in recent times due to a significant increase in trafficintensities, and the level ofservice expected ofhighway facilities.Improved level ofservice of the highways will result in considera-ble savings in vehicle operating cost and in favourable road userreaction and public opinion. Quality control in the form ofsen-sory checks which are intrinsically subjective and qualitative isgrossly inadequate for present-day needs and must instead be based

on proper objective and quantitative measurements.

1.1.2. It is common knowledge that quality control, besidesleading to constructions of improved quality ~nd uniformity, andensuring a more economical utilisation of materials, also affords a

significant reduction in user costs, in terms of lower costs ofvehicleoperation, transportation and maintenance. The extra cost of

exercising quality control being only a fraction ofthe resultingbenefits, is a highly economical proposition, in as much as on anaverage project it is estimated that the cost of exercising quality

control would be just if to 2 per cent of the construction cost.On the other hand, the direct and indirect economic return fromquality control could be ofthe order of 5 to 10 per cent ofthe totalconstruction cost and even more.

1.2. Pre-requlsites for Quality ControlThe pre-requisites for effective control of highway construc-

tions are

(i) Construction specifications and estimate, should provide foreffective quality control.

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(ii) Adequately trained staffand equipped agency for exercising qualitycontrol should be set up.

(iii) Periodic appraisal of the quality control data should be made notonly for implementation during construction but also for effectingpossible improvements in quality control and constructiontechniques themselves.

(iv) Updating ofknowledge by onjob training.

L3. Organisational Set-up for Quality Control

1.3.1. The requirements ofa quality control organisation willobviously vary on different projects depending on the departmentalset-up of the concerned highway agency. For. example, the organi-sation ofquality control work at a single centrally situated large

project will need to be on quite different lines than at average sizedscattered projects. In this chapter only the broad guidelines forthe organisation of quality control work at road projects arediscussed. The actual set-up may be evolved in the background

ofvarious factors involved. For the suggested pattern ofqualitycontrol set-up in this handbook a typical Organisational set.up habeen drawn up and shown below:

Organisational Chart ofQuality Control Set-up

ENGINEER-IN-CH!EFJCHIEF ENGINEER

DIRECTORHead ofquality control, should not be below the rank ofS.E.Located at Head-Quarter or where Central Laboratory Exists

REGIONAL LABORATORIESHeaded by Executive Engineer QfC will deal with specific cases,

all policy matters, training ofstaffetc.

~1

I Field Laboratory

Depending upon thejob it will deal with theroutine field tests at site ofthe work

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1.3.2. In any organisational set-up, the central agency hasan important role as regards implementation ofquality control

standards by way of drafting and constant review ofthe qualitycontrol criteria included in the construction specifications. Theimplementation ofquality control in the field would normally invo-

lve three sub-agencies viz, the construction staffofthe Engineer-in-Charge, the constructing agency and the quality control team. Theconstruction staff and quality control teams must have distinctlydefined functions and inter-relationships so as to avoid possibleconflicts. The quality control team may consist ofstaff ofregionallaboratories and field laboratories working under the technical

direction of the Central Laboratory.

1.3.3. As far as the field laboratories are concerned, the per-iodic quality control data collected by them should be promptlyfed to the site engineer, as the latter is responsible for ensuring

quality and speed of construction. In addition, the data will alsobe submitted to the Superintending Engineer/Chief Engineer aswell as to the Head of the Central Laboratory; to the former witha view to ensure continuity as well as compatibility ofthe

specifications in practice, and to the latter for purpose offeed-back. This may be regarded as a tentative recommendation,subject to review and modification, as and when experience accu-mulates.

1 .34. The expenditure on quality control may be chargedto the works and the staffas well as equipment shifted from projectto project depending upon the requirements. The quality control

staff should not be on work-charged basis but form part ofregularstaff and be properly trained for the work they are required tohandle, for which suitable training facilities should be afforded bythe department, either in their own Central Laboratory or anyother Laboratory. To provide for the cost ofquality control, it issuggested that this may be included as a distinct item in the variouswork estimates.

1.4. Types ofQuality Control

1.4.1. Over the years. tw o types of methods have emergedfor exercising quality control during the construction of works.One is generally known as Process cdntrol and the other as End

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result type of control. In the former, the designer makes thedecisions regarding the type of equipment, the procedure ofcon-struction and the amount of work required to obtain the desiredresult. In the End result type of control, the construction agency,which may be a private contractor, has a free hand in the selectionci construction methods and equipment to achieve the desired end

product.

1.4.2. The choice ofeither type ofcontrol is largely a matterof judgment, depending on the magnitude ofthe job, differentenvironmental factors involved, and the available facilities. InIndia, gradually the .*rend is towards End result type ofworkingon highway pavement and embankment construction jobs. But In

several situations, for example on small jobs, or where .input typeof tests like material gradation and purity of lime are to be carriedout, expediency would be in adopting Process type of control.Because of circumstances, a combination of the Process and Endresult types ofcontrol will continue to be adopted in India, depen-

ding on the nature and size ofthe job.

1.4.3. in the End result type of specification, the fieldengineering personnel carry out tests on finished work at regular

intervals to evaluate, whether it meets the specification require-mentS or not. On the other hand, in Process type control, theresponsibility offield personnel is to make sure that the work in itsdifferent phases is executed in the manner predetermined and laiddown in specifications.

1.4.4. The details given in this Handbook arc for a combina-tion ofProcess and End result types of quality control which is

generally being practised in this country.

1.5. Specifications for Work

The handbook draws heavily upon the existing Standards!

Specifications of Indian Roads Congress by way ofabstractingessential requirements of construction for the various items ofwork. Reference is given to the relevant Standards at appropriateplaces in the Handbook. A complete list of all the standards refer-red to with their full title is included at Appendix 1.

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1.6. Control of Materials

1.6.1. The quality control testsorl materials indicated in thesubsequent chapters, are intended essentially to be carried out onthe material brought to site. However, at times, from practicaland other considerations, some testing could be done advantageou-

sly at the material source. In these circumstances, the Engineer-in-Charge may do additional testing at site as may be found neces-sary to ensure that the materials being incorporated in the constru-ction are of specified quality.

1.6.2. All the materials brought to the site shall be stackedand stored as specified so as to prevent deterioration or intrusionby foreign matter and to ensure the preservation of their quality

and fitness for work. Materials which have been improperly storedor have been stored for long periods shall be re-tested where theirsuitability for incorporation in the work is in doubt.

1.7. Test Procedures

1.7.1. The procedure for testing of different materials andwork shall be in accordance with the relevant standards ofIndian

Bureau ofStandards where these are available. Reference has beendrawn to these standards at appropriate places in the Handbook.A consolidated list of the standards with their full title is at

Appendix 2.

1.7.2. Where specific procedure of testing is not indicated, thetests shall be carried out as per the prevalent accepted engineering

practice to the direction of the Engineer-in-Charge.

1.8. Frequency and Extent ofTesting

The frequency and extent oftesting indicated in the Handbookis the minimum considered necessary for normal conditions. It isenvisaged that additional testing shall be carried out for abnormalconditions where variations may be excessive or where circumstan-ces so warrant otherwise.

I .9. Acceptance Criteria

1.9.1. Acceptance Criteria for different items ofwork wheresufficient experience was available have been setforth in the

Handbook in respective chapters. For other items, acceptance

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may be based on minimum values or statistical analysis as isconsidered judicious.

1.9.2. For effective control on quality of materials and work,it will usually be necessary to lay down the acceptance criteria in

the contract documents.

1.10. Range of Equipment for a Central, Regional and FieldTesting Laboratory

1.10.1. Range ofequipment required for a central, regionaland field testing and control laboratories is indicated in Appen-dix 3 for guidance. The list includes such equipment as willnormally be required for quality control operations spelt out in the

Handbook. Individually, quality control units could be suitablyequipped with the help of this list depending on the type andvo l lime of work to be controlled. Special equipment as given in the

appendix can be procured depending upon the requirement.

1.10.2. Testing facilities : Testing facilities should comprise

Laboratories at Central, Regional and Field levels. The Centrallaboratory located at headquarterswill (a) provide testingfacilities for tests ofspecialized nature, (b) act as regional labora-tory for works circle (s) at headquarters, (c) act as the nodallaboratory for Research schemes in the State and Central sectors,(d) bring out manuals for testing procedures. The Central labora-tory headed by the Director. may have for quality control work,scientists from Geology, Chemistry and Physics disciplines. Thelist of suggested equipment to be provided in Central laboratory

are avilable at Appendix 3.

The Regional laboratories located at circle level will be hea-ded by Executive Engineers (Quality Control) assisted by scientists

from Geology, Physics and Chemistry disciplines. Regional labor-atories will provide testing support to the (a) Engineers working inthe circles and (b) Research teams from Central and State HighwayR & D institutions. In addition they shall provide all facilities for

training ofall the Quality Control staffin the Region. The list ofsuggested equipment to be provided in Regional laboratories isgiven at Appendix 3.

It is neither feasible nor advisable to send samples for routine

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tests all the way to the Regional laboratories and delay the workfor want of test results. Setting up facilities for basic tests at thelevel ofJunior Engineer/Engineering subordinate is therefore neces-sary. Sonic other equipments may have to be provided at sub

Divisional/Divisional level. A list ofequipment suggested to beprovided at Site/Sub divisional/Divisional level can be seen atAppendix 3.

- II . Recording, ofthe Test Results

The tests shall be carried out in accordance with the standardprocedures and the results shall be recorded in the proformae given

at Appendix 4. It is desirable that of the total tests, 70 pc~centare carried on by the Junior Engineer, 20 per cent by the Assistant!

Deputy Engineer and the remaining 10 per cent by the ExecutiveEngineer. The test result record registers shall be presentedwith every third running bill so that the payments get linked withthe assured quality ofwork.

1 .12. TraIning for Quality Control

In order to bring awareness in the officers ofdepartment andto update their knowledge ofmethods oftesting, regular workshops

on quality control should be held. - To make the participants awareof basic necessities like specifications, required test acceptancecriteria, frequency of testing and methodology of tests for under-standing the quality control system and operation of regional/fieldlaboratories. The training could be imparted by known roadresearch institutes or through on job training.

1.13. Scope ofthe Handbook

1.13.1. This Handbook is intended to be ahandy referencefor the general work of quality control at various highway constru-ctions. It is not in any way meant to be a substitute for the rele-

vant departmental specifications for construction and materials, but

only as a guide to complement these. For certain items, whereneed w as felt, broad guidelines on salient construction features havebeen included in the Handbook. These are for guidance only and

should not be taken to constitute specifications.1.13.2. Even though the Handbook is intended mainly for

highway constructions, it will be found equally advantageous for anumber offacets of runway constructions as well.

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ar wor

2

Earthwork

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CHAPTER 2

EARTHWORK

2.1; General

2.L1. It is the responsibility of the field engineer to ensurethat the density assumed by the designer is achieved at theexpected moisture content. The way to ensure this is to testsamples for moisture and density and to take appropriate correc-tive measures, as necessary. The rate oftesting on a given projectwould depend on several factors, such as the homogeneity orotherwise of the material from the borrowpits, the nature andquantum of machinery or manual labour employed, and terrain

conditions, so that the number of particular tests to be conductedfor say 1000 cubic metres ofthe material involved, would entirelybe a matter ofengineering judgment. Therefore, the frequencyof testing indicated at the end ofthis chapter should be regarded

as indicative of the minimum number of tests to be conducted withfull realisation ofthe fact that the rate of testing would have to be

increased if circumstances so warrant.

2.1.2. Discussion of other aspects such as the minimumdensities to be obtained, selection of rolling equipment, thicknessof layer, etc~,are considered to be outside the scope of thischapter. For guidance in this respect, reference should be rn:idc

to the relevant specifications, IRC 36-1970 RecommendedPractice for Construction of Earth Embankments for RoadWorks.

2.2. EarthworkMaterials and Process Selection ofSoils

2.2.1. The soil to be used for making up the embankment

shall be free from stumps and root rubbish which might affect the

stability ofthe embankment.

2.2.2. The selection ofmaterials for construction ofthe em-bankment shall be made after conducting necessary soil surveysand laboratory investigations, as set out in IRC : 36-1970.

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2.2.3. Only approved materials should be utilised in thebody of the embankment.

2.2.4. Ptoce.slng and placement : To obtain adequate com-paction, the embankment shall be constructed in uniform layers.

Due care shall be exercised to ensure that loose thickness of

each layer does not exceed the specified limits. Successive layersof embankment shall not be placed until the Layer under construction has been thoroughly compactedto satisfy the specifiedrequirements.

2.2.5. After adjusting the moisture content whether at theroad side or at borrow area, (making due allwance for evapora-tion losses), the soil shall be processed by means of graders,harrows, rotary mixers, other suitable equipment or even manuallyifno equipment is available until the moisture distribution is reasoeably uniform. Clods or hard lumps ofearth where present shall bebroken down to sizes preferably ofthe order of 5 cm but underno circumstances shall the maximum size of clods exceed 15 cmwhen soil is being placed in the body of the embankment and 6 cmwhen it is being placed in the top 50cm of the embankment.

2.2.6. Moisture content at the lime of compaction: Unlessotherwise specified, the moisture content of each layer of soil atthe time ofcompaction except in the case of highly expansive soilsshould be at optimum moisture content subject to the permittedtolerances. Highly expansive soils such as black cotton soilshould be compacted at the specified moisture content whichis usually on the higher side of the optimum

moisturecon-

tent. The tolerance limits for variation ofmoisture content fromthe specified moisture content are normally + 1 per cent and 2per cent.

2.2i. Densities to be aimed at in the compaction processshall be chosen with due regard to factors such as soil type, heightof embankment, drainage conditions, position of the individual

layers and type ofplant available for compaction.

2.2.8. Each compacted layer shall be tested in the field fordensity and accepted before the operations for the next layercommence.

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Earthwork 15

2,3. Trial Compaction

2.3.1. In situations where no previous record or experienceconcerning the needed number ofpasses with a particular rolling

equipment relating to a particular soil type is available, it may bedesirable to conduct field trials on compaction so as to obtain data

which would serve as an aid to planning ofcompaction operations.

2.3.2. A test area about 20 m long and 5 m wide is preparedafter removing the top soil. The fill material to be used is spread

over this area, the depth of the loose layer being 25 cm. TheTnositure content of the soil should be as specified subject to thetolerance limits indicated.

2.3.3. The test layer is then compacted with the type ofcompaction plant decided upon, and the mean dry desnsity to thefull depth determined over the range of about 4 to 16 passes. Thenumber ofpasses required are dependent upon the weight and typeofrollers employed. The dry density shalt be determined in acco-rdance with IS: 2720 (Part-XXVHI) and the mean of5 determina-tion should be obtained for each compaction condition. The meandry densities are plotted against the number ofroller passes. Fromthis graph, the approximate number ofpasses required for the com-paction equipment to obtain the specified dry density is determined.

2.4. Quality Control ofEarthwork

2.4.1. Quality of fill material and its compaction shall becontrolled through exercise ofchecks on the borrow material, com-paction process, or the end-product, singly or in combination asdirected. However, in every case, the end-product must conformto the construction specifications.

2.4.2. Details of control tests on borrow materials and com-paction are dealt with in Clauses 2.5. and 2.6.

2.5. Control Tests on Borrow Material

2.5.1. The particular type oftests required to be conductedon the borrow material and their frequency would depend on

interplay of several factors such as the nature ofplant or machi-nery employed on the project, the quantum ofmanual labour in-

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16 Earthwork

volved, the nature of specifications to be followed whether they cal

for particular tests on borrow niat~rials,the uniformity or othewise of materials coming out of borrowpits, terrain conditions, etcThe recommended frequencies indicated in the succeeding par

graphs and in Table 2.1. are therefore only to be taken as applicabl

to routine cases. These tests are meant to verify during executioofthe work that the material coming to site conforms to specifica

iOflS, for borrow matetial and should be regarded as distinct frothe test referred to in Clause 2.2.2. which relate to the initial seletion ofsoils for embankment construction. All the tests would nobe applicable on all projects. Depending upon site conditions, etc.only particular tests may be found necessary for a particulaproject. The frequency of testing indicated releates generally t

the minimum number oftests to be conducted. The rate oftestinwould have to be stepped up much more than is herein indicated

depending upon the heterogeneity ofthe material and the compation technique adopted in any particular project.

2.5.2. Gradation (IS: 2720Part JV)1965 : At least, one tefor each kind ofsoil. Usual late oftesting, 1-2 tests per 8,000 mofsoil. The test would be necessary only if specifications call fochecks using gradation or grain-size distribution as a criterion foselecting the soil. However, sand content determinations shoulbe carried out invariably, at the rate of 1-2 tests per S0O() m~

2.5.3. Plasticity index (IS: 2720Part V)1970 : At least, on

test for each kind ofsoil. Usual rate ~f testing 1-2 tests per 800

m3 ofsoil.

2.5.4. Proctor test (IS: 2720Part Vll)1965 : This test i

performed to ensure that soil of requisite quality is coming out oborrow areas as also to provide information on optimum mc~stucontent and maximum laboratory dry density. Usual rate at tesing, 1-2 tests per 8000 m3 ofsoil.

2.55. 1~eteteriousconstituents (IS: 2720Part XXVH)1968The soil shall be free of harmful salts like sodium sulphate an

organic matter (permissible limits)~of0.2 and 1 per cent respetively. The tests will be done as and when required.

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2.56. Natural moisture content (IS 2720Part 11-1973)(Second Revision): One test for every 25 0 ma ofsoil. The naturalmoisture content ofthe soil coming out ofthe borrowpits will haveto be determined in order to evaluate how far the natural moisturecontent tallies with the optimum value and whether further addi-

tion or reduction of water cctntent would be necessary.

25.7. Table 2.1. gives a summary of the tests for borrowmaterials discussed above along with minimum desirable fre-

quen cies.

2.6. CompactIon Control

2.6.1. Compaction control mainly involves two operations,namely, control of moisture content just before compaction anddensity of compacted layer.

2.6.2. MoIsture content determinations: Moisture contentdeterminations for compaction control shall be in addition to thoseon borrow material spelt out in Clause 2.5.6. Thit test is necessary

for ensuring proper moisture content at the time ofcompactionwhich significantly influences the density results. Usual rate of

testing should be 2-3 tests per 250 in3 ofsoil.

2.6.3. Density measurements: Except when otherwisedirected, at the last one measurement ofdensity shall be made foreach 1 000 in2 of compacted area. Test locations shallbe chosen

only through predetermined random sampling techniques. Controls~a11not be based on the result ofanyone test but on the meanvalue of 5-10 density determinations. The number oftests in oneset of measurements shall be 5 as long as it is felt that sufficientcontrol over borrow material and the method ofcompaction was

being exercised. But if there be any doubt about this control, orconsiderable variations are observed between individual densityresults, the number oftests in ont set of measurement shall forthwith be increased to 10. The acceptance ofresults shall be subjectto the condition that the mean dry density equals or exceeds the

specified density and the standard deviation for any set of results isbelow 0.08 gm per cc.

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2.6~4. In general, the control at top subgrade layers of theformation shall be more strict than stated above with density mea-

surements being carried out at the rate of 1 test per 500-1000 m2

ofcompacted area. Further, for the determination ofmean density

~nd standard - deviation (refer Chapter 8), the number of tests inone set of measurements shall not be less than 10. Acceptance of

the work shall be subject to the same conditions as stipulated inClause 2.6.3.

2.6.5. Table 2.2. sets out the minimum desirable frequency

oftests for compaction control.

TABLE 2.1. C0Nm0L Tssrs ON Boa.aow MATERIALS

S.No. Test Test method Minimum desira-ble frequency

1. UradationtlSAnd- lS~2720 Part IV-1965 1-2 tests per 8000 m2content ofsoi l

2. Plasticity index IS: 2720 Part V-1970 do

3 . Standard Proctor IS: 2720 Part VII-1965 doTest

4. CBR on a set of3 IS: 2720 Part XVI-19 65 O ne test per 3000 mspeCimens* *

5. Deleterious consti- IS: 2720 Part XXVII-1968 As requiredtuents

6. Natural moisture IS: 2720 Part 11-1973 One test per 250 m

content (Second Revision) of soil

*jfspecifications call for such teSts.

**For purposes ofdesign only unless otherwise specified.

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TABLE 2,2. TESTS FOR CoMPAcTioN CONTROL

Minimum desirablefrequency

I. Moisture content

just before Compaction

IS: 2720 Part 11 2-3 tests per 250 in

1973 (Second Revision) ,floose soil.2. Dry density

ofcompacted layer15 : 2720 Part XXVIII1966

Generally, one iestper 1000 & of com-pacted area for thebody ofthe embank-ment to be increasedto one test per500-1000 m ofcom-pacted area for topsubgrade layers, i.e.top 500 mm portionofthe embankment.

S. No, Test Test method

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-

3

Sub-baseCourses

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CHAPTER 3

SUB-BASE COURSES

3.1. General

3.1.1. The following sub-base courses are dealt with in this

Chapter

(i) Stone Soling

(ii) Brick Soling

(iii) Water Bound Macadam Sub-base(iv) Soll-Gravei(Moorum Sub-base

(v) Mechanically Stabilized Soil

(vi) Lime Stabilized Soil

(vii) Cement Modified Soil(viii) Sand-bitumen Mix

3.2. Stone Soling

3.2.1. General

3.2.1.1. Stone soling, as a rule, is gradually becoming out-moded as a sub-base owing to its inferior load spreading proper-ties as well as the liability to sink into poor or slushy subgrades.

However, where it is still used, control on the materials and worksshould be exercised as described hereunder.

3.2.2. Materials

3.2.2.1. Before incorporation in th.e work, the materials forstone soling shall be checked for specification requirements eitherat the quarry or at the site.

3.2.2.2. The stones shall be granite, limestone, sandstone,

etc., as specified, reasonably free from laminations, foreign matter,unsound and weathered fragments and be in a clean condition.

3.22.3. The filler material shall be sand or any othergranular material having a plasticity index ofnot more than 6.

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3.2.3. Processing and construction

3.2.3l. Preparation of snbgrade: The subgrade shall bechecked for line, grade and cross-section as spelt out in Chapter 7.All irregularities beyond the permitted tolerances shall be rectified.

Soft and yielding places and ruts shall be corrected and rolled

until firm.

3.2.3.2. Soling work The follo~ingpoints shall be kept inview during execution:

(I) The stones shall be laid and seated properly by hand as specified.

(ii) All voids should be filled, first by wedging in spalls and then withfiller material accompained by sprinkling o f water, brooming and

rolling.(iii) Rolling shall commence a t the edges, progressing gradually

towards the centre parallel to the centre line of the road except atsupercievated portions where it shall proceed from the inner edgeto the outer.

(iv) Thefinished surface shall be checked for lines level and regularityas indicated in Chapter 7.

3.2.4. Control tests and their frequency

3.2.4.1. Quality control tests on materials and work as well

as their minimum desirable frequency shall be as shown in

Table 3.1.

TABLE 3.1.

S. No. Test Test method Minimum desirablefrequency

1. Aggregate Impact Value/ IS: 2386 One test per 200 m

Los Angeles Abrasion (Farl IV) 1963

Value

2. Plasticity index offiller IS: 2720 One test per 25 m

material (Part V)1963

3 . Control ofgrade, camber, Vide Regularlythickness and surface Chapter 7finish

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3.2.5. RectificatIon ofsurface irregularities

3.2.5.1 Irregularities present in the finished surface beyondthe tolerances specified in Chapter 7 shall be rectified in thefollowing manner:

When the finished surface is too high or too low, the solingshall be dismantled to the full depth and reconstructed as specified.Jn no case shall the filling of depressions with filler material bepermitted.

3.3. Brick-Soling

3.3.1. General -

3.3.1.1. Bricks for soling works may be laid in one or morelayers either flat or on edge.

3.3.2. MaterIals

3.3.2.1. The quality of bricks shall be checked for specfica-tion requirements before their incorporation in the works. Bricksto be used shall be of full size and brickbats shall not be used.

3.3.2.2. The filler shall be sand or any other material having

a plasticity index of not more than 6.


3.3.3.1. Preparation ofsubgrade: Clause 3.2.3.1. shall apply.

3.3.3.2. Soling work: The following points shall be kept in

mind while executing the work(I) [he bricks shall be hand laid with each brick touching the other.

(ii) Pattern for laying of bricks, such as herringbone, shall be as speci.fled. When more than one layer is to be constructed, the bricksshoi~ldbe so laid as to break joints in successive layers.

(iii) The material used for filling the interstices shall be sand or any othermineral matter with plasticity Index not exceeding 6~


3.3.4.1, Quality control tests on the materials and the workand their minimum desirable frequency shall be as indicated in

Table 3.2.

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TA~t.E3.2.

S. No. Test I est method Minimum desirablefrequency

1. Crushing strength of

bricks

IS: 3495

tPart Ito lv) 1973First Revision

5 bricks to be testedfor every 5O,~U~bricks

2. Water absorption ofbricks

IS: 3495(Parts Ito V)1973

First Revision

do

3. Plastcity mdcx of

filler material

IS: 2720

(Part V)-1970First Revision

One test per 25 m

34. Water Bound Macadam Snb-base

3.4.1. General For use as sub-base water bound macadamsha~lbe constructed with oversized aggregates of40-90 mm size. The

materials used and the work shall conform to the requirements of1RC: 19-1977 and their quality shall be contro~leci~in the samelines as outlined in Chapter 4 for water bound macadam basecourse.

3.5. SoII_Gra,el/Moorum* Sub-base

3.5.1. General : This type of sub-base is constructed using

mooruni, soil-gravel mixtures and similar naturally occurring low-grade materials.

3.5.2. Materials : The materials shall be in accordance withthe specifications as laid down.

3.5.3. ProcessIng and construction

3.5.3.1. PreparatIon ofsubgrade: Clause 3.2.3.1. shaU apply.

- *Moorum is the name usually given to naturally occurring materials

formed by disintegration ofrock.

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35.3.2. Construction of sub-base: The following points

shall be kept in mind during execution of the work:

(1) Before compaction, mois ture content o l the material shall bebrought to the desired level.

(ii) Rolling shall commence at the edges, proceeding gradually towardsthe centre parallel to the centre line of the road, except at superele-vated portions where it shall proceed from the inner edge to the

outer. Rolling shall be continued till the specified density isachieved.

(iii) The surface after rolling shall be well closed, free from movementunder compaction plant, any compaction planes, ridges, cracks or

loose material.,

(iv) After rolling, the sub-base layer shall be checked for density, thecontrol and permissible tolerances for which shall be the same as

set out in Clause 2.6.4. This presupposes that Proctor density isknown through prior testing.

(v) Unless otherwise specified, no traffic of any description shall plydirectly over the finished sub-base.

3.5.4. Control tests and their frequency: Quality controltests on materials and work with their minimum desirablefrequency are indicated in Table 3.3.

TADLC 3.3.

S. No. Test

I. Gradation

2. Plasticity

3 . Natural moisture content

4. Deleterious constituents

5. Moisture Contents prior to

compaction

6. Density ofcompacted layer

7. Control of grade, camberthickness and surfacefinish

8. CBa test (on a set of3 specimens)

Test Minimum desirablemethod frequency

IS : 2720 O ne test per 200 m(Part IV)1965

IS: 2720 -do-(Part V)1970IS: 2720 One test per 250 m

(Part II)i973(First Revision)IS: 2720 As requiredtPart XXVII)IS: 2720 Onetest per 250 m(Past II)1973~SecondRevision)IS : 2720 One test per 500 m~(Part XXVIII)1966Vide Regularly

Chapter 7

IS : 2720 As required(Part XVI)1965

* This test, unless specified otherwise In the Specifications, is for the purposeofdesign only, -

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3.5.5. RectificatIon ofsmiace irregularities

3.5.5.1. Where surface irregularities of the finished sub-baselayer fall outside the specified tolerances given in Chapter 7, thesame shall be rectified. If the surface is too high, it shall be

trimmed and suitably compacted. If it is too low, the deficiency

shall be corrected by adding fresh material. The degree ofcom-paction and the type of material to be used shall conform to thespecification requirements.

3.6. Mechanically Stabilized Soil

3.6.1: General

3.6.1.1. Mechanical stabilization is mainly of three differenttypes, namely, stabilization ofsandy soils with admixture of clay,stabilization ofclayey soils with admixture of sand and stabilizationwith soft aggregates.

3.6.2. MaterIals

3.6.2.1. The blending/grafting materials used for mechanical

stabilization shall be checked for specification requirements.


3.6.3.1. Preparation of subgrade: Clause 3.2.3.1. shall apply.

3.6.3.2. Mixing and laying of stabilized soil : The following

ooints shall be kept in mind while executing the work:(i) Stabilization shall be carried out preferably by mechanical melDs.

In all cases, it shall be ensured that the plant used and met!~bdsadopted are capab]e o f pulverising the soil to specified degree tofull thickness of the layer being processed and of achieving thedesired degree of mixing and uniformity of the stabilized material.

(ii) in the event of manual mixing, it shall be ensUred that there hasbeen uniform mixing of various ingredients to the full depth oflayer processed,

(iii) Degree of pulverisation shall be as specified.

(iv) Grading and plasticity index of mixed material, where specified,shall be checked.

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(v) Before compaction, moisture content of the mixed material shall bebrought to the desired level, which in general is the same as theoptimum moisture content.

(vi) In the case of stabilization ~~ithaggregates, it shall be ensured thatthe aggregates are evenly dispersed in the stabilized layer.

(vii) Rolling shall commence at the edges, proceeding gradually towardsthe centre parallel to the centre line of the road, except atsuperelevated portions where it shall proceed from the inner edgeto the outer. Rolling shall be continued till the specified density isreached.

(viii) The surface after rolling shall be well closed, free from movementunder compaction plant, any compaction planes, ridges, cracks or

loose material

(ix) After rolling, the sub base layer shall be checked for compaction,the control and permissible tolerances of which shall be the same

as set out in Clause 2.6.4. This presupposes that Proctor density isknown through prior testing.

(x) The surface shall be cured as s ~c1tied.

(xi) The finished surface shall be checked for line, level and regularityin accordance with Chapter 7.

(xii) Unless otherwise specified, no traffic of any description shall plydirectly over the stabilized layer.


3.6.4.1. Quality control tests on materials and work with

their minimum desirable frequency shall be as indicated in Table3.4. Specific tests and their frequencies on soft aggregates where

required to be used are also included in Table 3.4. Where forany test, the procedure oftesting is not indicated, the same shallbe performed as per accepted engineering practice.

3.6.5. Rectification ofsurface irregularities

3.6.5.1. Where surface irregularity of the stabilized layerfalls outside the tolerances mentioned in Chapter 7, the same shall

be rectified. Ifthe surface is too high, it shall be trimmed andsuitably compacted. If it is too low, the deficiency shall be correc-ted by adding fresh material. The degree of compaction and the

type of material to be used shall conform to the specificationrequirements.

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TAaLa 3.4.

Subbase Courses

S. No. Test Test Minimum desirablemethod frequency

I. Aggregate Impact value

2. Water absorption* ofaggregates

3, Degree ofpulverisatlon

4. Plasticity index ofmixed

material

5. Sand content ofmixed

material6. Moisture content prior to

cornpaction

7. Dry density of compactedlayer

8. Control ofgrade, camber,thickness and surface finish

9. CBR test on materialmixed at site (aset of3specimens)

10. Deleterious constituents

IS : 2386(Part IV)1963

IS 2386(Part I1I)1963

15: 2720(Part V)1970(First Revision)IS : 2720

(Part IV)1965IS 2720(Part II)1973(Second Revision)

IS: 2120(Part XXVIII)-1966Vide Chapter 7 Regularly

IS : 2720 One test per 3000 in(Part XVI) 1965

IS 2720 As required(Part XXVII)-1968

* Where apphcable.~ This test is for the purpose ofdesign only unless otherwise specified.

3.7. Lime Stabilized SoiljMoorum

3.7.1. General Besides lime stabilized soil, this sub-sectioncovers constructions involving stabilization with lime of materials

like moorum.

3.7.2. MaterIals Lime, at delivered at site, shall be

checked for purity and available calcium oxide content as specifiedThe quantity of lime for incorpo#ation in the soil related to its

calcium oxide content, shall be expressed as per cent by weightof the dry soil. The lime content shall be predetermined on the

basis of laboratory tests.

One test per 200 in6

One test per 200 in

Regularly

One test per 1000 in

do

O ne test per 250 in6

One test per 500 m

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3.7.3.1, Preparation ofsubgrade: Clause 3.2,3.1. shall apply.

3.7.3.2. Stabilization: The following points shall be kept inmind while executing the work:

(i) Stabilization shall be carried out preferably by mechanical means.If single pass stabilisers are not available, rotavators or agriculturalmachinery like ploughe and disc harrows shall be made use of. Inevery case, it shall be ensured that the plant used and methodsadopted are capable ofpulverising the soil to specified degree overthe full thickness of layer being processed and of achieving themixing and uniformity of the stabilized material to desired degree.

(ii) In the case ofmanual mixing, it shall be ensured that there has beena uniform mixing of lime and soil to the full depth ofthe layerprocessed.

(iii) Degree ofpulverisation shall be as specified.

(iv) Mixing shall be uniform and no streaks offree lime shall be visible.

(v) After mixing, the lime content ofthe mix shall be determined. Thelime content values shall conform to the following (also see foot noteunder Table 3.5):

(a) Moving average of 10 tests not to be less than the specifiedlime content.

(b) No test value to i~eless than 75 per cent ofthe specified limecontent.

(vi) Before compaction, moisture content ofthe mixed material shall be

brought to the desired level, which, in general, is she optimummoisture content.

(vii) It shall be ensured that the time interval between mixing of lime withsoil and compaction does not exceed three hours.

(viii) Rolling shall commence at the edges progressing gradually towardsthe centre parallel to the centre line ofthe road, except at superele-vated portions where it shall proceed from the inner edge to theouter. Rolling shall be continued till the specified density isachieved.

(ix) Care shall be taken to ensure that during rolling the compactionplant does not bear directly on hardened or partially hardenedtreated material previously laid except as may be necessary for

achieving the desired compaction a t thejoints.

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(x) The surface after rolling shall be welt closed, free from movement

under compaction plant, and anycompaction planes, ridges, cracksor loose material.

(xi) After rolling, thesub-base layer shall be checked for compaction thecontrol and the permitted tolerances ofwhich shall be the same as setout in Clause 2,6.4. This presupposes that Proctor density is known

through prior testing.

(xli) The finished surface shalt be checked immediately after laying torline, level and regularity in accordance with Chapter 7.

(xiii) The surface on completion shall be cured for 7 days soon after which

subsequent pavement courses shall be laid to prevent the surfacefrom drying out and becoming friable. No traffic of any descriptionshall ply directly over the stabilized layer.


3.7.4.1. Quality control tests on materials and work withtheir minimum desirable frequency are indicated in Table 3.5.Where for any test the procedure of testing is not indicated, thesame shall be performed in accordance with accepted engineeringpractice.

3.7.5. Rectification ofsurface irregularities

3.7.5.1. Where the surface irregularity ofthe stabilized layerfalls outside the specified tolerances given in Chapter 7, the same

shall be rectified.

3.7.5.2. Where the su~face is top high, the same shall be

suitably trimmed while taking care that the material below is notdisturbed by this operation.

3.7.5.3. However, where the surface is too low, the sameshall be corrected as described hereafter. When the time elapsedbetween detection of irregularity and the time ofmixing of thematerial is less than 3 hours, the surface shall be scarified to a

depth of 50 mm, supplemented with freshly mixed material asnecessary and recompacted to the requirements. Where the elapsed

;ime is more than 3 hours, the full depth ofthe layer shall be re-moved from the pavement and replaced with fresh material as

specified.

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TAnLE 3.5.

S. No. Test Tes t method Minimum desirablefrequency

1. Purity of lime and avail-able calcium oxide

IS: 1514-1959 O ne test for eachconsignment . subject

to minimum of oneteat per 5 tonnes oflime

2. Lime content immedia-tely after mixing

IS: 1514@-1959 O ne test per 25 0 m2

3. Degree ofpulverisation Regularly4. Moisture content prior to

compactionIS: 2720(Part II)-1973(Second Revision)

One test per 250 m

5 . Dry density ofcompac.ted layer

IS: 2720(Part XXVIIE)-1966

One test per 500 m

6. Control of grade, cam-bet, thickness andsurfacefinish

VideChapter 7

Regularly

7. CBR test on materialsmixed at site (a set of 3

specimens)

IS: 2720(Part XVI)-1965

One test per 3000 m

8.

.________

Deleterious constituentsofsoil

IS: 2720(Part XXVI)-1973

(First Revision)

As required

@Tbis test method is inconvenient for wide application in thefield. As such,it will be desirable to exercise close control over material quantities and theirprocessing.

* Unless otherwise specified, this test is only for the purpose ofdesign.

3.8. Cement Modified Soil

3.8.1. General

3.8.1.1. Cement modified soil is envisaged to be with lowercement content for use as sub-base, as distinct from soil-cement

intended to be used for base courses.

3.8.2. MaterIals

3.8.2.1. Soil proposed for cement stabilisation shall not havea sulphate content of more than 0.2 per cent. The cement usedshall be checked for compliance with the requirements of IS: 269-(1967), 455.1967 (Second Revision) or 1489-1967 (First Revision)as applicable. The quantity of cement for incorporation shallbe expressed as a percentage by weight of dry soil. This shall be

predetermined on the basis of laboratory tests.

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34 Sub-base Courses


3.8.3.1. Preparation of subgrade: Clause 3.2.3.1. shall apply.

3.8.3.2. Preparing and laying ofcement modified soil sub-base:

The operations involved in processing and construction of cement-modified soil are the same as those for lime stabitzed soil except

that the stabilizing material will be cement instead of lime. Assuch, Clause 3.7.3.2. shall apply but for the maximum timeinterval between mixing of cement with soil and compaction which

shall be 2 hours in this case.

3.8.4. Control tests and their frequency Quality controltests on the materials and the work and their minimUm desirablefrequency shall be as indicated in Table 3.6. Where for any testthe procedure oftesting is not indicated, the same shall be carried

out as per the prevalent engineering practice.

TAlL! 3.6.

S. No..

Test Test method Minimum desirablefrequency

1. Deleterious constituents IS : 2720(Part XXVII)-1968

As required

2. Quality ofcement IS 269/455/1489 do3. Cement content immedia.

tely after mixing~ One test per 250 m1

4. Degree ofpulverisation Regularly

5. Moisture content prior tocompaction

IS : 2720(Part I1)-1973(Second Revision)

One test per 250 m

6. Dry density IS : 2720(Part XXVIII)-1966

One test per 500 m~

7. Control ofgrade, camberthickness and surfacefinish

VideChapter 7

Regularly

8. CBR test on materials

mixed at site (a set of 3specimens)

IS : 2720

(Part XVI)-1965

One test per 3000 m

@Under finalisation with 1St. This test method Is inconvenient for wide appli-cation in the field. As such, It will be desirable to exercise close control overmater*aI quantities and their processing.

This test unless otherwise specified is for the purpose ofdesign only.

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3.8.5. Rectlficstion of surface irregularities: Clause 3.7.5.shall apply except that the time criterion spelled out in

Clause 3.7.5.3. shall be 2 hours in this case.

3.9. Sand-bItumen Mix

3.9.1. General: Sand-bitumen can be used both as sub-

base and base, the composition being designed accordingly.

3.9.2. MaterIals

3.9.2.L Sand shall be non-plastic. The per cent fractionfiner than 75-micron sieve shall be within the range of 5 and 10.

3.9.2.2. Binder shall be as specified. The per cent bindercontent in the sand-bitumen mix shall be predetermined in the

laboratory.


3.9.3.1. Preparation of subgrsdes: Clause 3.2.3.1. shall apply.

3.9.3.2. Sand-bitumen mix laying: The following points

shall be attenced to while executing the work:

(i) Mix proportions ofconstituent materials shall be as specified.

(ii) Where sand is found to be.wet, it shalt be dr-led before mixing withbinder.

(iii) The means adopted for mixing shall be as specified and it shall beensured that sand particles are uniformly and properly coated withbinder.

(iv) The sand-bitumen mix shalt be laid a t site and if the binder is a cut-back aerated for about 24 hours. It shall then be regarded toproper camber and rolled.

(v) For this type ofconstruction, edge confinement shall be provided.

(vi) The thickness ofindividual layer of sand-bitumen mix shall be asspecified.

(vii) Provisions regarding rolling shall be the same as described in

Clause 3.7.3.2. (vlll-x).(viii) After rolling, the compacted layer shall be checked for density as

laid down.

(ix) The finished surface shall be checked for line, level and ~egularityin accordance with Chapter 7.

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-3.9.4. Control tests and their frequency : Quality control

tests on the materials and the work and their minimum.desirable

frequency shall be as indicated in Table 3.7.

TASLF 3.7.

S. No. Test Test method Minimum desirablefrequency

I. Sand fraction finer than75 micron sieve

IS : 2720(Part IV)1965

As required

2. Plasticity index of aandIS : 731961

IS : 2171961

IS: 2720(Part V)1970(First Revision)

As required

3. Quality ofbinder- IS : 73/217 do-4. Binder content ofmix Method, vide

Append(x-4One test per 50 m

1subject to a mm. of2 tests per day

5 *Stabilityofsandbitumen

mix by Hubbard-Fieldmethod

ASTM~D-ll38 One test for 50 m

6. Density ofcompacted mix IS 2720(Part XXVIII)

1966

One test for 500 m

7. Control ofgrade, camber,thickness and surfacefinish

VideChapter 7

Regularly

*To be

criterion.performed only when stability has been specified as an acceptance

3.9.5. RectIfication of surface irregularities : Where thesurface irregularity ofthe sand-bitumen layer sub-base is outsidethe specified tolerances as given in Chapter 7, it shall be rectified.

The rectification shall be done while the mix is still workable.Where the surface is too high, the same shalt be suitably trimmedwhile taking care not to disturb the material below. Where thesurface is too low, the depressed areas shall be filled up with

sand-bitumen mix and rolled according to specification

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4

Base Courses

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CHAPTER 4

BASE COURSES

41. General

4.1.1. The following base courses are dealt with in thisChapter:

(a) Water bound macadam:

( 1 ) Surfaced(ii) Unsurfaced

(b) Bituminous penetration macadam

(C) Built-up-spray grout

(d) Bituminous macadam(e) Soil-cement base

(f) Lean concrete

(g) Lime puzzolana concrete(h) S a n d - bitumen base

4,2. Water Bound Macadam

4.2.1. General: Water bound macadam may be used as abase course under a surfacing or as a wearing course without any

surfacing. In either case, the construction shall generally be in

accordance with I1(C: 19-1972.

4.2,2~ Materials : All materials used in WBM construction,viz., coarse aggregates, screenings and binding material shall be

checked in advance of their incorporation in the works for speci-fication requirements, either at the quarry or at site.


4,2.3,1. Preparation of sobgrade/sab-base: This shall be

checked for line, grade and section in accordance with Chapter 7.~,iIts or soft yielding places shall be corrected suitably and rolled~until firm. Arrangement of lateral confinement ofaggregate shall

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be checked before starting to spread of materials. Ifnecessary, the

surface shaH be scarified and reshaped to the required grade and

camber.

4.2.3.2. The following points shall be carefully attended towhile executing the work

(i) Quantity and uniformity ofspread o f materials shall be checked by

template (see Chapter 7).

(ii) Segregation ofcoarse and fine aggregates shall be avoided.

(iii) Rolling operations shall begin from edges, proceeding gradually tothe centre while lapprng each preceding rear wheel trackby onehalfwidth. T he weight and type ofthe roller shall be relevant to

the type of coarse aggregate. At horizontal curves, rolling shallproceed from the inner edge to the outer. No roiling shall becarried out when it causes a wave-like motion due to softness of thesubgrade/sub-base. Irregularities that develop during rolling shallbe rectified either by adding or removing aggregate. In no caseshall screenings be added to make up depressions. Rolling shall bediscontinued when the aggregates are partially compacted with voidspace sufficient to permit application ofscreenings. However, wherescreenings arenot to be used, compaction shall be continued until

the aggregates are thoroughly keyed.

(iv) Screenings shall be applied in three or more apptiL~tions to fillthe interstices while dry rolling is continued. Vehicles carryingscreenings shall be so operated as not to disturb the coarseaggregates.

(v) It should be ensured that the sub-base/subgrade does not get

damaged due to addition of excessive quantities of water during

construction.

(vi) Binding material, if required, shall be added after the applicationof screenings. It shall be introduced at a uniform zate in two or

more applications accompanied by copious, sprihkling of water soas to form a slurry which could he swept with brooms to fill the

remaining voids. Rolling shall be continued till full compaction isachieved.

(vii) No traffic shall be allowed till the macadam s ets . In c a se o f surfacetreated water bound macadam, the surfacing shall be laid oniyauier the macadam base is completely dried.

(viii) The finished surface shall be checked for line, level and regularityIn accordance with Chapter 7.

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4.2.4. Control tests and their frequencynn the materials and the work and their

frequency shall be as indicated in Table 4.1.

TABLI 4.1.

Quality control testsminimum desirable

3 . Flakiness index ofaggregate

4. Plasticity of binding material

Test method Minimumdesirablefrequency

4.2,5. Rectification of surface irregularities: Where the

surface irregularities of water-6ound macadam base are outsidethe tolerances mentioned in Chapter 7, the same shall be rectifiedby lemoving to full depth theaflected area, which should not beless than 10 m

2, and relaying with fresh materials. In no case

shaU depressions be filled up with screenings or binding material.

4.3. Bituminous Penetration Macadam

4.3.1. General : Construction of bituminous penetrationmacadam base shall in general be carried out in accordance with.IRC: 20-1966. Control over the quality of materials and workshall be exercised as set forth hereunder.

S. No. Test

1. Los Angeles Abrasion ValucJ

Aggregate Impact Value

IS: 2386

(Part JV}1963

One test

per 200 m

2. Grading 01 aggregate andscreenings

IS: 2386(Part I)1963

One testper 100 m

iS: 2386(Part I)1983

One testper 200 m~

IS: 2720

(Part V)1970One test

per 25 m

5. Control ofgrade, camber, thicknessand surface f inish

VideChapter 1

Regularly

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4.3.2. Materials

4.3.2.1. Coarse aggregates : - The aggregates should be

checked for conformity with the requirements stipulated inIRC: 20-1966.

4.3.2.2. Bituminous binder: The type and grade ofbituminousbinder shall be as specified. The binder shall be checked for itsquality before and during construction as may be.required.


4.3.3.1. PreparatIon of subgrade/sub-base: Clause 4.2.3.1.

shall apply.

4.3.3.2. Construction ofbituminous penetration niacildam base

course : The following points shall be given proper attention

during construction:

(I) The coarse aggregates shall be spread uniformly and checked by

template (see Chapter 7).

(ii) Provision for rolling and checking of finished surface shall be the

same as in Clause 4.2.3.2. Provided however that rolling shall stopbefore thevoids are closed to such an extent as to prevent free anduniform penetration ofbinderand key aggregates.

(iii) Bituminous penetration macadam work shall not be carried outwhen the atmospheric temperature In shade Is less than 16Cor

when the underlying course is damp or wet.

(iv) The specified quantity of approved bisaler shall be sprayed at theappropriate application temperature, preferably using mechanicalsprayers. The ends of the stretch shill be covered with thick paperso a s to avoid double spraymg of binder. The rate of spray ofbinder shall be frequently checked and regulated to be within 21 percent of the specified rate ofapplication. Excessive deposits ofbin~Iershall be immediately removed.

(v) Key stones shall be uniformly spread immediately after theapplication ofbituminous binder by mechanical or manual means.The surface shall be broomed to obtain a uniform distribution of

key stones and rolled.

4.3.4. Control tests and their frequencks: Quality control

tests on the materials and the work and their minimum desirablefrequencies shall be as indicated in Table 4.2.

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Base Courses 43

Test method Minimum desirablefrequency

3.

Lo s Angeles Abrasion Value/Aggregate Impact Value IS: 2386 One test per 200 m(Part IV}l963

2, Aggregate gradatioft

3 . Flakiness index

4. Stripping value

5. Quality ofbindei

6. Rate of spread o f binder

7. Rate of spread of key

aggregates

IS: 2386(Part I)1963

iS: 2386(Part I)l963

IS:624l1971

IS: 73/215/217/454

Method videAppendix 4

do

One test per 100 m~

Onetest per 200 m3

One test per 200 m3

As required

Regularly

Regularly

8. Temperature of binder at

application

Regu1ar~y

9. Control ofgradc~camber,thickness and surface finish

Vide Chapter ~7 Regularly

4.3.5. Rectification of surface irregularities : Vide Clause 4.2.5.

4.4. Built.up Spray Grout

4.4.1. General : Construction of built-up spray grout shall

generally be done in accordance with IRC : 47-1972. The quality

of materials and work shall be controlled on the same lines as

outlined in Clause 4.3. for bituminous penetration macadam.

4.5. Bitumsnous Macadam

4.5.1. General : Construction of bituminous macadampremix base shall generally be done in accordance with IRC27-1967. For ensuring the requisite quality of materials, and work,the important points to be kept in view and the control tests to becarried out are set forth below.

TAaLi~4.2.

S. No. Test

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44 Base Courses

4.5.2. Materials

4.5.2,1. Coarse aggregates: The aggregates shall be checked

for the requirements spelt out in IRC:27-1967.

4.5.2.2. Bituminous binder : Clause 4.3.2.2. shall apply.

-1.5.3. Processing and construction

4.5.3.1. Preparation of subgrade/sub-base Clause 4.2.3.1.shall apply. 1~addition, the surface shall be thoroughly cleaned,first with wire brushes and finally by dusting with sacks.

4.5.3.2. Construction ofbituminous macadam : Proper atten-

tion shall be paid to the following points during construction

(i) The bitt~minousmacadam construction shall not normally be carriedout when the atmospheric temperature (in shade) is less than l6~Corwhen the underlying course in damp or wet.

(ii) All mechanical equipment, like hot-mix plant, paver roller, etc.,shall be checked br their work worthiness.

(iii) Where specified, a tack coat of bituminous binder shall be appliedon the base/sub-base and control shall be exercised on the rate

uniformity and temperature of its application.(iv) Mix pruportions of the constituent materials shall be as specified.

Binder content with mix shall be ch~ekedperiodically and controlledso that there is no variation beyond 0,3per cent by weight ofthetotal mix.

(v) Unless otherwise specified, mixing of aggregates and binder shall becarried out in hot-mix plant.

(vi) Binder and aggregate temperatures shall be consistent with propermixing and laying of the mix and be within the specified limits.

(vii) Mix shall be spread uniformly preferably using a paver-finisher tothe correct thickness, grade and camber. Temperature of the mixat the time of laying and rolling shall be within the specified limits.

(viii) Tne roller shall proceed on to fresh material with the drive wheel

leading. Rolling shall commence from the edges and progresstowards the centre except on superelevated curves where the rolling

shall commence from the lower edge and progress towards the upperedge. The rolling shall be continued, with off-set of halfrear wheelwidth, till the layer has been fully compacted. The wheels ofthe

roller shall be kept moist to prevent the mix from adhering to themand being picked up but in no case shall fuel/lubricating oil be usedbr this purpose.

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Base ourses 45

(ix) Longitudinal joints and edges shall be constructed true to thedelineating lines parallel to the centre line ofthe road. All jointsshall be cut vertical to the full thickness ofthe previously laid mixand the surface painted with hot bitumen before placing freshmaterial.

x) Traffic shall not be normally allowed on ~hccourse till the mix has

cooled down to the surrounding temperature.(xi) T he finished surface shall be checked for line, level and regularity in

accor~lancewith Chapter 7.

4.5.4. Control tests and their frequencies: Quality controltests on the materials and the work and their frequencies shall be

as indicated in Table 4.3.

TABLE 4.3.

2. Lo s Angeles Abrasion Value!Aggregate Impact Value

IS: 731961(Revison)

IS: 2386(Part IV).1964

One test for 50-100m~of aggregate

3 . Flakiness index ofaggregate

IS: 2386(Part I)1963

do--

4. Stripping value ofaggregate

5. Mix grading

6. Control oftemperature ofbinder and aggregate andof the mix at the time oflaying

IS: 62411971 do

Two tests per dayon both the consitu-ents and mixedaggregate from thedryer

7. Control ofbinder contentand aggregate gradationin the mix

Methodvide

App. 4

Periodic, subject tominimum of twotests per day perplant

S. No , Test Test Minimum desirablemethod frequency

- Quality ofbinder As required

IS: 2386(Part L)1963

Regularly

8. Control ofgrade, camber~thickness and surface finish

Vide Chapter 7 Regularly

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4 Base Courses

4.5.5. RectificatIon of surface irregularities: Where thesurface irregularities of the bituminous premix macadam base

course are outside the tolerances given in Chapter 7, these shall berectified as per procedure given in Clause 4.2.5.

4.6. Soil-Cement Base

4.6.1. General: As distinct from cement modified soil, thisconstruction is envisaged to be of base course quality with mix desi-gned as per strength and durability considerations.

4.6.2. Materials: Clause 3.8.2. shall apply except that the

materials shall be proportioned to achieve the specified compressivestrength.


4.6.3.1. Preparation of subgrade/sub-base: Clause 3.2.3.1.shall apply.

4.6.3.2. lreparing and laying soil-cement base : Clause3.8.3.2. shall apply.

4.6.4. Control tests and their frequency : Quality control testson materials and work and their minimum desirable frequencyshall be as indicated in Table 4.4. Where for any test, the proce-

dure oftesting is not indicated, the same shalt be carried out as perprevalent engineering practice.

The strength of the material mixed at site shall be controlledby carrying out cube strength tests. It shall be ensured that in aset of ten test results, the average strength shall be equal to ormore than the specified strength and that not more than one test

shall give a value less than the specified value by more than 10per cent.

4.6.5, RectIfication of surface irregularities Clause 3.8.5.

shall apply.

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Base ourses

I - Deleterious constituents of

soil

2. Quality of cement

IS: 2720-1968(Part XXVII)

As rcqu~rcd

IS: 269f455f . do1489

3. Cement content

4. Degree of pulverisatlon

5. Moisture content prior to

compaction

6. Dry density

7. Control ofgrade, camber,thickness and surface finish

IS : 2720(Part H)-1973

IS : 2720(Part XXVIU)-1968

Vide Chapter 7

O ne test per 250 m~

do

do---

One test per 500 m2

Regularly

8. Cube strength of mater-ials mixed at site (aset of2 specimens)

IS 516-1959 One test for 50 mofmx

@ Under finalisation with 1St. This this method is inconvenient for wideapplication in the field. As such, it wilt be desirable to exercise closecontrol over material quantftles and their processing.

4.7. Lean Concrete

4.7.1. General

4.7.1.1. This type ofconstruction is suitable as a base bothfor flexible and rigid pavements.

4.7.2. MaterIals All materials, viz. cement, sand, cnarseaggregates and water used in construction shall satisfy the relevant

specification requirements. The mix proportions f~rlean concreteshall be predetermined in the laboratory so as to obtain the speci-

fied compressive strength at 28 days.4.7.3. Processing and construction

4.7.3.1. Preparation of sub.gradelsub-base/bas : Cldttse3.2.3.1. shall apply. In addition, where the lean concrete is to he

TABLE 4.4.

S. No. Test Test Minimum desirablemethod frequency

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48 Base Courses

laid over an absorbent suhgrade/sub-base(base, the latter shall bekept moist so as to prevent absorption of water from the concrete

marta r.

4.7.3.2. Mixing and laying of lean cement concrete: Atten-

tion should be paid to the following points while carrying out thework:

(i) Unless otherwise permitted, the mix shall be prepared in a power-driven batch mixer ofapproved type.

lii) Proportioning of constituent materials including water shall strictlybe as specified. Due allowance shalt be made for the free moisture

content ofaggregates.(iii) Concrete immediately after mixing shall be transported for placement

in such a manner that segregation or loss ofconstituent materialsis avoided.

(iv) Concrete shall be spread uniformly and thesurface struckoff withsurcharge over the desired finished Level. The amount of surchargeshall be determined in the field by actual trial. The surcharge shallbe uniform over the entire area and the concrete as spread shall beto thesame camber and slope as desired in thefinished surface.

(v) No joints other than constiuction joints shall be provided.

(vh Concrete shall be compacted with a suitable roller within the periodspecified which will not exceed 2 hours since mixing of the material.

(vii) During compaction, the grade and camber of the surface shallbe checked and all irregularities corrected by removing or adding

fresh material.

(viii) Where lean concrete is to be laid in two layers, the second layeshall be placed within one hour ofcompaction ofthe lower layer.

(ix) A minimum of 72 hours ofcuring shall be done before placing thenext pavement course. If the next pavement course Is not laidimmediately after this period. curing of the lean concrete shallcontinue subject to a maximum period of14 days.

(x) Strength of lean concrete shall be controlled by carrying out cubestrength tests. It shall be ensured that in a set of ten test results,the average strength shall be equal to or more than the specifiedstrength and that not more than one test shall give a value less thanthe specified value by more than 10 per cent.

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4,7.4. Control tests and their frequency

4.7.4.1. Quality control test on the materials and the work~nd their minimum desirable frequency shall be as indicated inrahle 4.5.

TABLE 4.5.


1. Quality ofcement

2. Los Angeles AbrasionValue/Aggregate impact

Value3 . Aggregate Gradation

4. Aggregate moistureContent

5. We t analysis o f mix

6. Control o f grade,camber, thickness and

surface f inish7. Strength ofcubes (2

specimens for eachage of7 and 28 days)

IS:269- 1967/4551967/ As required14891967

IS: 2386 (Part IVt1963 On e test per 20) m

iS: 2386 (Part 1)1963 One test per 100 m~

IS: 2386 (Part lll).~-1963 As require~1

IS: 11991959 As required

Vide Chapter 7 Regularly

IS: 5161959 One teci for 50 m mix

43.5. Rectification ofsurface irregularities

4.7.5.1. The finished surface shall be checked for line, level,

grade and surface finish as in Chapter 7. The checking andrectification should be effected when the mix is still plastic.Surface irregularities left in hardened layer will have to beremoved by cutting out sufficiently large patches and relaying to

specification.

48. LIme-Puzzolana Concrete

4.8.1. General: This type of construction is suitable as.a

base both for flexible and rigid pavements.

4.8.2. Materials All materials, viz., lime-puzzolana mix-

ture, sand, coarse aggregate and water used in construction shallsatisfy the relevant specification requirements. The mix propor-

S. No. Test

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1. Quality oflime~puzzolana mix

2. Los Angeles AbrasionValue/Aggregate ImpactValue

TABLE 4.6.


4.8.5. RectificatIon ofsurface irregularities: Clause 4.7.5. 1.

shall apply.

4.9. Sand-bitumen Base

tion for the concrete shall be predetermined in the laboratory soas to obtain the specified compressive strength at 28 days.


4.8.3.1. Preparation ofsubgrade : Clause 3,2. .1. shall apply.

4.8.3.2. Mixing and laying of lime puzzolana concrete: Theprocedi:re of mixing, transporting, placing, compacting, curing and

strength control shall be the same as that for lean concrete videClause 4.7.3.2.

48.4. Control tests and their trequency

4.&4.l. Quality ci~ntroltests on the materials and the work

nid their minimum desirable frequency shall be as indicated inTable 4.6.

S. No. Test

3 . Aggregate gradation

IS: 40981967

IS: 2386 (Part IV)

1963

IS: 2386 (Part I).1963

As required

O ne test per 200 m

O ne test per 100 m

As required

Regularly

O ne test for 50 rn

4, Aggregate moisture IS: 2386 (Part Ill)content 1963

5. Control of grade, Vide Chapter 7camber, *hckness andsurface f inish

6. Strength ofcubes (2 IS: 5161959specimens for eachage of7 and 28 days)

Clause 3.9. shall apply.

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tum nousSurface Courses5

Bituminous

Courses Surface

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CHAPTER 5

BITUMiNOUS SURFACE COURSES

5.L The following bituminous surface courses are dealt~ith in this Chapter

(1) Single and tw o coat bituminous surface dressing.

(2) Surface dress ing usin g pre-coated aggregates.(3) Thin bituminous premix carpet.

(4) Asphaltlc concrete surfacing.

5.2. Single and iwo-coat Bituminous Surface Dressing

5.2.1. General: Construction of bituminous surface dressingin single or two coats shall generally follow the specificationslaid down in IRC : 17-1965 and IRC:23-1966 respectively.

5.2.2. Materials

~.2.2.l. The materials, namely, aggregates and binder

should be checked for specification requiremei~tsstipulated inIRC:17-1965 or TRC:23-1966 as applicable.


5,2.3.1. Preparation ofbase: All depressions or potholesin the base on which surface dressing is to be laid shall be properlymade up and compacted to the required lines1 grade and section.

Any fat patch on the existing surface sball be corrected. Thesurface shall be thoroughly cleaned of any caked earth and othermatter before the binder is applied. Where the base is an oldbituminous surfacing, the extent and manner of rectification willbe as indicated. Where specified, bituminous prime coat shallbe applied and cured before laying the surface dressing. The edgesof the surface to be treated shall be properly defined Theprepared base shall be checked for line, grade and section in

accordance with Chapter 7 and all irregularities beyond the per-mitted tolerances corrected.

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54 um nous ur ace ourses

5.2.3.:. Construction ofbituminous surface dressing : Whilc

executing the work, the following points shall be kept in mind

(I) No surface dressing work shall be carried out if

a. atmospheric temperature in shade is less than 16C,or

b. base Is damp, or

c. construction materials are damp, or

d. the weather is fogey, rainy or dusty.

(ii) The work should be so Organised that no traffic or dust gets on tothecleaned or bituminous painted base,

(iii) The specified quantity ofapproved binder shall be sprayed at theappropriate application temperature, pref~rablyusing mechanicalsprayers. The ends of the stretch shall be covered with thick papcr

so as to avoid double spraying of binder. The rate of spray ofbinder shall be frequently checked and regulated to be within 21 per

cent of thespecified rate of application. Excessive deposits of bindershall be immediately removed.

tiv) Immediately after application of the binder, cover aggregates ofapproved quality shall be spread uniformly at the specified rate. Ifnecessary, the surface shall be broomed to ensure uniform spreadingofaggregate.

(v) Cover aggregates shall be immediately rolled with roller of approvedweight. Rolling shall commence at the edges progressing graduallytowards the centre parallel to the centre line ofthe road except atsuperelevated portions whcre it shall proceed from the inner edgeto the outer. Rolling operation shall continue till all aggregatesparticles are firmly embedded in the binder. Excessive rolling resul-

ting in the crushing of aggregates shall be avoided.

(vi) The second coat, if specified, shall be applied immediately afterlaying ofthe first coat,

(vii) Generally, no traffic shall be allowed on the finished surface for24 hours. If allooed, its speed shall be restricted to 16 km per

hour during this period. Ifcut-back bitumen has been used, thefinished surfaceshall be closed to traffic till the binder is adequately

cured,

5.2.4.~ Control tests and their frequency: Quality controltests on the materials and the work and their desirable frequency

shail be as indicated in Table 5.1.

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Bituminous Surface Courses 55

2. Los Angeles AbrasionValue/Aggregate ImpactValue

3. Stripping value ofaggregate

4. Flakiness index ofaggregate

5. Water absorption ofaggregate

6. Grading ofaggregate

TAaL~5.1.

Minimum desirablefrequency

IS: 731961 As required2151961, 2171961or 454 as applicable

IS 2386 One test per 50 m(Part IV)-l963

iS : 62411971 do-

IS 2386 do(Part l~1963

is: V86 do(Part IIl)1963

lS~2386 Onetestper25m(Part I)1963

7 Temperature ofbinderat application

Regularly

8. Rate ofspread of binder Tray test vide

Appendix 4

One test per 500 &

9. Rateofspreadofaggregate

Tray test videAppendix 4

One test per 500 m

5.2.5. RectifIcation ofsurface irregularities: Surface dressingby itself cannot remove any uridulations present in the base orthe surface on which it is applied, it is therefore essential thatall operations of rectifications to meet the requirements Set out inChapter 7, be carried out on the receiving surface before the workof surface dressing is begun.

5.3. Surface Dressing with Pre-coated Aggregates

5.3.1. General: Construction of bituminous surface dres-sing with pre-coated aggregates shall generally be carried out inaccordance with IRC : 48-1972. The construction is similar toconventional surface dressing except that the cover aggregates are

lightly pre-coated with binder. As such the quality of materials

S. No, Test

1. Quality of binder

Test method

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56 Bituminous Surface Courses

and work shall he controlled on the same lines as set out in (lause52. with additional checks on the following aspects

(I) At the time of mixing, the binder and cover aggregates shall be at

their app. opriate temperatures.(ii~Coating of the aggregates with binder shall be unifotrn.

(iii) The aggregates after coating shall be aerated and cooled properlybefore using them in wt~k. During cooling, these shall not be piled

in big heaps and care shall be taken to protect them from dust.

.4+ Thin Bituminous Premix Carpet

5.4 I. General : Thin bituminous premix carpet may heconstituted from pen graded or closely graded mixes a~specified.Where the mix is open graded, tie car p~tis generally provided v~ith

a seal coat. The construction for open-graded premix surfacingshall be in accordance with IRC 14.19/0.

5.4.2. Materials The materials, namely, aggregates andbinder should be checked for specification requirements (IRC 14-

1970 or other relevant specification).


54.3.1. Preparation ofbase: Clause 5.2.3.1. shall apply.

5.4.3.2, Construction ofpremix carpet : The following pointsshall be properly attended to during construction of this type ofsurfacing

(ii Mix proportion of constituent materials shall be as specified. Bindercontent in the mix shall be checked periodically and regulated tobe within 24 per cent of the specified quantity.

(ii) Tack coat, where necessary, shall be applied uniformly over tbeprepared base at the specified rate.

(iii) Mixing shall preferably be done in mechanical mixers.

(iv) Where straight-run bitumen is used, the aggregates should be suit-ably heated prior to mixing with binder. The binder heated toappropriate temperature should be mixed wi th aggregates until theatter are thoroughly coated.

(v) The mixed materials shall be spread evenly with rakes or spreaders

to specified thickness and camber.

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Bituminous Surface Courses 57

(vi) Rolling shall start immediately after the material is spread. Thewheels of the roller shall be kept moist to prevent the premix fromadhering to the wheels and being picked up but in no case shall theuse offuel lubricating oil be permitted for this purpose.

(vii) Where specified, a seal coat comprising premix sand or liquid sealand f ine aggregates shall be evenly applied and rolled. The points to

be attended to during application ofseal coat shall be the same asthose for Surface Dressing (Clause 5.2.) and Thin Premix Carpet(Clause 5.4.) when the seal is of liquid type and premix sand respecti-vely.

(viii) When straight-run bitumen is used, traffic ma y be allowed imme-diately after the carpet has cooled down to the surrounding tempe-rature but with restricted speed of16 KMH for the next 24 hours.However, wher cut-backbitumen is used, traffic shall not be permit-ted till the binder is cured.

(ix) The finished surface shall be checked for line, level and regularity inaccordance with Chapter 7.

5.4.4. Control tests and their frequency Quality control

tests on materials and work with their desirable frequency areindicated in Table 5.2.

5.4.5. Rectification of surfac~Irregularities : Premix carpetscan improve the evenness of an existing surface only in a limitedway. Therefore, if there are large irregularities in the surfacethese should he rectified just prior to laying of the carpet. Wherethe surface irregularities of the finished carpet are outside thetolerances given in Chapter 7, these should be rectified in themanner described here. If the surface is too high, it shall be cutout and replaced by fresh materials laid and compacted to sped-

fications. Where the surface is too low,

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