Pavement Deterioration ‘A Case Study On National Highway 8b Section Rajkot-Bamanbore (Km 185/0-

Km 216/8)’Rushikesh P. Dangar

PGStudent Civil Engineering Department,Birla Vishvakarma Mahavidyalaya,

VallabhVidyanagar, Gujaratrushi88@yahoo.com

DR. L.B.ZalaCivil Engineering Department,

B.V.M. Engg. College,VallabhVidyanagar, Gujarat

lbzala@yahoo.co.in

DR. F.S.UmrigarPrincipal,

B.V.M. Engg. College,VallabhVidyanagar, Gujarat

bvm_princi@yahoo.com

Abstract—Pavements are complex structures involving many variables, such as materials, construction methods, loads, environment, maintenance, and economics. Thus, various technical and economic factors must be well understood to design, build pavements, and to maintain better pavements. Moreover, the problems relating to pavement maintenance are still complex due to the dynamic nature of road pavements where elements of the pavement are constantly changing, being added or removed. These elements deteriorate with time and therefore to be maintained in good condition requires substantial expenditure.The paper analyze the condition survey of the NH 8-B (Section Rajkot-Bamnabore (km 185/0-km 216/8)). It gives an idea about problem of pavement deterioration and pavement condition at present.

Keywords- pavement; deterioration; maintenance; dynamicnature

I. INTRODUCTION

Pavements are complex structures involving many variables, such as materials, construction methods, loads, environment,maintenance, and economics. Thus, various technical and economic factors must be well understood to design, build pavements, and to maintain better pavements. Moreover, the problems relating to pavement maintenance are still complex due to the dynamic nature of road pavements where elements of the pavement are constantly changing, being added or removed. These elements deteriorate with time and therefore to be maintained in good condition requires substantial expenditure.

II. LITERATURE REVIEWA highway pavement is a structure consisting of

superimposed layers of processed materials above the natural soil sub-grade, whose primary function is to distribute the applied vehicle loads to the sub-grade. The pavement structure should be able to provide a surface of acceptable riding quality, adequate skid resistance, favorable light reflecting

characteristics, and low noise pollution. The ultimate aim is to ensure that the transmitted stresses due to wheel load are sufficiently reduced, so that they will not exceed bearing capacity of the sub-grade. Two types of pavements are generally recognized as serving this purpose, namely flexible pavements and rigid pavement. Improper design of pavements leads to early failure of pavements affecting the riding quality.Pavement deterioration is due to traffic and environmental factors.

The exact way in which a pavement deteriorates is of great importance to a maintenance engineer to work out the maintenance strategy.

The pavement deterioration usually is not the result of poor design and construction but also it is caused by

The inevitable wear and tear that occurs over years.

Variation in climate.

Increasing multi axles vehicles and heavy traffic.

The types of deterioration in flexible pavement are grouped as under four categories

a. Surface defects- which include fatty surface, smooth surface, streaking surface and hungry surfaces

b. Cracks- which include hair line cracks, alligator cracks, longitudinal cracks, edge cracks, shrinkage cracks and reflection cracks

c. Deformation- which include slippage, rutting, corrugation, shoving, shallow depression and settlements and upheavals

d. Disintegration- which include stripping, loss of aggregate, ravelling, pot holes and edge braking.

In each case of pavement deterioration, the causes of deterioration will be first determined. It will be possible to provide suitable maintenance measures which will not only correct the damage but also prevent the deterioration. In many

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situations lack of proper drainage is the principle cause for stripping, loss of material from the pavement and shoulder, weakening of the pavement layers and subgrade etc resulting in the failure of the pavement. In such cases the cause should be completely eliminated before taking any maintenance measure.

The main pavement deficiency was the aggregate base, which in some locations was much less than the original pavement recommendations. Water migrated into the base causing the compacted clay subgrade to become wet with a corresponding reduction in shear strength.

Because of the thin aggregate base, the pavement section could not sustain the traffic loads, resulting in alligator cracks, rutting and, in some cases, complete disintegration of the pavement. It was also observed that water was flowing through the aggregate base. For inclined pavements with a permeable aggregate base constructed on top of a clay subgrade, theoretical analysis indicates that the majority of water will flow through the base material instead of into the subgrade.

Common damage due to heave of the compacted clay subgrade are cracks in the asphalt concrete that are parallel to the curbs and gutters.

Once cracked, the asphalt pavement allows for further infiltration of water, accelerating the heave process. Besides this crack pattern, there can be a variety of heave and crack patterns in pavements on expansive clay subgrade.

Another effect of moisture infiltration into the compacted clay subgrade is a reduction in the shear strength of the soil. Moisture causes a softening of the compacted clay. The process involves a reduction in negative pore pressures, which results in a loss of effective shear strength. This makes the subgrade weaker and more susceptible to pavement deterioration, such as alligator cracking and rutting. One way to understand the detrimental effects of a clay subgrade is to study actual cases of pavement deterioration.

III. NH8B (Bamanbore-Rajkot-Porbandar) Study Section

Importance of National Highway-8b (Bamanbore-Rajkot-Porbandar)

National highway 8B is a part of east – west corridor project of NHDP. East – West corridor project is for connecting the Silchar from East region of India to Porbandar West region of India. National highway 8B connects the Porbandar-Rajkot-Bamanbore and from Bamanbore its further connect to National highway 8A and this National highway 8A further connect to National highway 8 which is a part of a Golden Quadrilateral. Which connect the Delhi (capital of India) to Mumbai.

Porbandar is a coastal city in the state of Gujarat. It has large industries like Surahstra Chemical Limited (Birla VXL Limited), Surahstra (Hathi) Cement Limited etc. And it is best known for being the birthplace of Mahatma Gandhi (father of nation) and Sudama (Friend of Lord Krishna).

Rajkot is the 4th largest city in the state of Gujarat. Rajkot district is located in the south-west region of the state of Gujarat. Rajkot is ranked 22nd in The world's fastest growing cities and urban areas from 2006 to 2020. Transportation is the

backbone to the development of urban areas. Trade and Industry fast developing in the Rajkot city.

Good connectivity is far important for the development of urban as well as rural area.

IV. PAVEMENT CONDITION ASSESSMENT

The pavement condition is assessed based on visual observation and measurement of pavement deteriorates at site. The condition classification as per IRC:81-1997 is given in table. The pavement condition observed at site is provided in table- II salient features and table III crust thickness.

TABLE I. CRITERIA FOR CLASSIFICATION OF PAVEMENTSECTIONS

Classification Pavement condition

Good No cracking, rutting less than 10 mm

Fair No cracking or cracking confined to single crack in the wheel track with rutting between 10 mm

and 20 mm

Poor Extensive cracking and / or rutting greater than 20 mm. Sections with cracking exceeding 20 %

shall b e treated as failed.

TABLE II. SALIENT FEATURE OF NH 8-B

1Right of Way or Land

width45.72 mt

2 Formation width 26.00 mt

3 Carriage way width2* 7.00 mt (four lane) +

2*1.50 mt (side shoulder)

4 Type of surface Bituminous surface

5 Temperature

Summer: Min: 24°C, Max:42°C

Winter: Min: 10°C, Max:24°C

6Average annual rain

fall 500mm

TABLE III. CRUST THICKENESS OF NH 8 B

Km(Up-lane)

185-189

189-207

207-214

214-216/8

Km

(down-lane)

185-216/8

Thickness in mm

675 715 630 750 Thickness in

mm

630

The traffic on National Highway-8B as an average of 7 days count is given here. The traffic observed on NH-8B in the year 2009 was 18163 CV per day and that in year 2010 was 22198 CV per day.

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�Traffic growth rate on this road is 22.21% as far as Commercial Vehicle (CV) per day is concern.

The condition survey observations are coded as Surface defects: A, Crack types: B, Deformation: C and Disintegration: D, are provided in table IV and observations of conditions are recorded in table V.

TABLE IV. MEASUREMENT FOR CONDITION SURVEY

Surface Defects

(A)

Crack type

(B)

Deformation

(C)

Disintegration

(D)

1.Smooth surface

1.Hairline crack 1.Ruts 1.Ravelling

2.Hungry surface

2.Alligator crack 2.Settlement 2.Pot holes

3.Longitudinal crack

4.Edge crack

5.Shrinkage cracks

6.Transverse cracks

TABLE V. CONDITION SURVEY ON NH 8-B

KM (UP-Lane)

Chainage DefectsCD work detail

Condition

185-186

185/2B-6(6mt), B-2

Over Bridge(2*23.175 c/c)

Fair

186-187

186/1,186/7,186/9

Bridge portion A-1, B-6 (6.2mt), C-2, B-2

Lalpari river bridge(5*21.92 c/c)

Poor

187-188

187/2187/5

Bridge joint B-6 (1mt), B-1

Fair

188-189

188/1

D-2 (32*20*3), (26*18*4), (19*10*2.5),A-2

Poor

189-190

189/2C-2,D-2 (19*25*1.5)

(3*2.30 c/c) Fair

190-191

190/4D-1,D-2 (32*24*3.3)

Fair

191-192

191/1- (3*1.60) Good

192-193

192/2 -(1*4.75) Good

193-194

A-1, B-2D-2 (13*19*2.3)

Fair

194-195

194/1- (1*1.70) Good

195-196

195/3B-1, D-2 (70*45*1.9) (55*30*0.8)

Fair

196-197

196/1- (2*1.35) Good

197-198

197/1- (2*1.25) Good

198-199

198/1- (1*1.60) Good

199-200

199/1- (3*6.90 c/c)

Good

200-201

D-2 (5*7*2.5) -

Good

201-202

201/1,201/2

D-2 (3*2.65*2)

(2*2.28 c/c)(1*1.95)

Good

202-203 202/2

Patch work shown not proper,D-1(602)

(3*4.75 c/c)Fair

203-204

203/1 -(3*2.65 c/c)

Good

204-205

204/2- (4*6.38 c/c)

Good

205-206

- -Good

206-207

206/1-

River Beti (machhu)(8*17.37 c/c)

Good

207-208

- -Good

208-209

- -Good

209-210

209/2D-1 (30 m2) -

Good

210-211

210/1C-2 (10*3.2mt2)

Banaiyo Bridge(4*16.0 c/c)

Fair

211-212

211/4 D-2 (18*35*1.8)

-Fair

212-213

212/1 D-2 (15*25*1.5)

-Fair

213-214

213/3Major C-2 Approx Area (25*4.5mt)

- Poor

214-215

- -Good

215-216

215/9 -(3*2.0 c/c)(1*2.50)

Good

216-216/8

- -Good

VI. CONCLUSIONThis paper describes the pavement deterioration at NH 8B

section Rajkot – Bamanbore (185/0 – 216/8). Pavement damage includes cracks, pot-holes, settlement and disintegration as given in above table and visually it can be shown by pictures given at below. It is thus concluded that thedamage is mostly due to heavy traffic and subsurface

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exploration revealing that the subgrade have clayey sand and that the main deficiency is the aggregate base, which in somecases are much less than the original pavement recommendations. The pavement deterioration probably starts when moisture migrates into the clay subgrade. Once the clay subgrade becomes wet, its shear strength is reduced and because of the thin aggregate base, the pavement sectioncannot sustain the traffic loads, causing the deterioration. It has been also observed that water flows through the base material. The base consisted of a granular material placed on top of a clay subgrade.Specific conclusions can be drawn as under based on observation.1. Pot holes are observed throughout the length of section.

Size ranging from 50*70 mm2 to 700*450 mm2

2. Transverse cracks are observed at initial stretch only.3. There are 4 major CD works.4. The pavement condition from chain age 185/000 – 196/000

km is poor to good, Chainage 196/000 – 210/000 is good and remaining is fair to good.

RECOMMENDATION

Chainage 185/000 – 196/000 required to be evaluated for non-destructive test for strength evaluation, i.e. Benkelman Beam Test for rebound deflection measurement recommended for overlay design.

Pictures taken at condition survey on National Highway 8-B (Section Rajkot-Bamanbore, km 185-216/8)

[PICTURES DO NOT SHOW ALL CONDITIONS THAT MIGHT BE FOUND.]

REFERENCES

[1] Ministry of Shipping, Road Transport & Highways “Specification for Road and Bridge Works” (Fourth Revision) by Indian Road Congress, New Delhi, 2001

[2] Dr. L. R. Kadyali and Dr. N. B. Lal, Principles and Practices of Highway Engineering, Khanna Publishers, Delhi-6.

[3] S. K. Khanna and C. E. G. Justo “Highway Engineering”, 1963, (Eighth Edition), Nem Chand & Bros, Roorkee.

[4] IRC:82-1982 Code of Practice for Maintenance of Bituminous Surfaces of Highways, Reprint March’99, by Indian Road Congress, New Delhi.

[5] IRC:SP:19-2001 Manual For Survey Investigation And Preparation Of Road Projects.(First Revision Dec-2001) by Indian Road Congress, New Delhi.

[6] IRC:81-1997 Guideline for strengthening of flexible road pavements using Benkelman beam deflection technique, (First Revision) by Indian Road Congress, New Delhi.

[7] The world Bank 1988, 'Road Deterioration and Maintenance Effects, Models for Planning and Management', The World Bank, Paterson, Washington, DC.

[8] Highway Research Board, National advisory committee HRB specification 616 (1962), Publication No.1061, Washington, DC.

[9] http://www.nhai.org (National Highways Authority of India

13-14 May 2011 B.V.M. Engineering College, V.V.Nagar,Gujarat,India

National Conference on Recent Trends in Engineering & Technology