Why so many potholes on city roads in India? How to repair them?

1
20 August 2011
[See Post Script dated 25 September 2014 at end of letter.]

Why so many potholes on city roads in India? How to repair them?

Every year during the monsoon there is public outcry about city roads riddled with
potholes. Newspapers are filled with pictures of potholed roads. Many of our highway
engineers when asked by the media give the following two reasons for the development
of potholes in urban areas: (a) rainfall during monsoon season, and (b) overloading of
roadway pavements. Both are fallacies to brainwash general public in believing that
potholes are natural especially during rainy season and they are beyond the engineers’
control. Many states in the US and many countries in Europe have rain almost throughout
the year. Besides, they also have freeze and thaw which is worse than rain. If we send our
highway engineers there, there will be potholes throughout the year. Also, overloaded
trucks hardly use the urban roads and streets.

After the potholes develop, our engineers use 18
th
Century technology to fill them during
the rainy season such as just placing soil and/or stone in the potholes, which is washed
away in the next rain.

I have simple solutions to both of the preceding problems that are (a) how to build roads
which are durable and not prone to developing potholes and (b) how to repair potholes
with a simple, effective, and durable mix even during the rainy season when the potholes
are wet.

I am an NRI who worked in the US as bituminous road engineer for over 35 years. My
specialty is to train highway engineers throughout the world in building durable
bituminous roads and also troubleshoot complex premature road failures (including
developing potholes). I have been to China three times to train their highway engineers in
building world-class, durable roads. Now, I have returned to India from the US to serve
my mother country on a volunteer basis. I do not have any vested interest whatsoever in
India during my retirement. Since my expertise is forensic investigation of road failures
throughout the world, I know exactly why roads are developing potholes left and right in
India both in urban as well as in rural areas.

The primary problem is that the road specifications issued by the Ministry of Road
Transport & Highways (MORTH) allow the use of 10 different bituminous mixes in road
construction. Of these 10 mixes, 7 mixes are unsuitable for road construction because not
being dense enough they trap water and cause potholes. Only three mixes are dense and
suitable for road construction. Unfortunately, we do not give any training to our highway
engineers. All they know is that bitumen is black and sticky. Being ignorant, they use less
dense (permeable) mixes, which also happen to be cheaper. First of all, why we need 10
different mixes? Most developed and developing countries in the world have a total of
only 3 or 4 real dense mixes for all types of road and street paving. Unfortunately, our
highway engineers with old mindset do not like to discard the water-trapping mixes. This
2
is especially crucial for city roads in India, where surface water drainage is usually
inadequate.

I have co-authored a paper on this subject of discarding the water-trapping, problem
mixes from our specifications. This paper was published in the Journal of the Indian
Roads Congress (IRC), Volume 69-2, 2008. It can be accessed at the following link:

http://www.scribd.com/doc/19380138/A-Critical-Review-of-Bituminous-Mixes-Used-
in-India

Based on my recommendations, the Jaipur Development Authority (JDA) which has a
large network of roads and streets, has now banned the use of problem mixes such
Bituminous Macadam (BM), Semi Dense Bituminous Concrete (SDBC), and DBM
Grading 1. Premix carpet (PMC) which is also porous despite the seal has also been
banned within city. JDA now allows dense graded mixes only such as BC Grading 1 as a
binder course for profile correction to improve drainage and BC Grading 2 as a wearing
course in resurfacing work. These mixes are expected to last 7-8 years generally free of
potholes. All cities and towns in India should follow JDA’s example.

On the subject of pothole repair, while in the US I had developed a simple and effective
cold bituminous mix, which can be used to fill potholes during the rainy season even
when they are wet. No preparation of the pothole is required for this “idiot proof” mix. In
a nationwide US study, this mix was adjudged as number one in terms of its durability in
potholes. When introduced in Pennsylvania this mix was unofficially called “Kandhal
mix” by contractors. It has been used in extreme cold and rainy weather in the US for
over 25 years. This durable readymade cold mix can be made and stored for 6 months. It
can be made by any bituminous mix plant in India using local materials. I have also
successfully tried it on Jaipur streets and on Jaipur-Agra Road with the help of the
students and faculty of Malviya National Institute of Technology in Jaipur. It also has
been tried successfully by the West Bengal PWD and IIT Guwahati.

The nuts and bolts of this unpatented, generic readymade mix, as to how it is made are
given in a paper published in the Journal of the Indian Roads Congress, Volume 69-3,
2008. This paper can be accessed at the following link:

http://www.scribd.com/doc/19380290/A-Simple-and-Effective-Method-of-Repairing-
Potholes-in-India

With my voluntary technical assistance, the JDA is producing and using this mix
successfully during this monsoon. They have issued work order worth more than Rupees
one crore based on the attached specification. Mr. Sapan Mishra, JDA Engineer, can be
contacted at [email protected] if you have any questions on its large scale
field use in Jaipur. Nobody can really help you if you still have doubts about its success
in the field.

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So what are you waiting for??? I hope we still have some dedicated, honest, and
enthusiastic mayors/engineers in the metros, PWD or anywhere in India who really care
for their city, state and country. Hopefully, they will produce this mix and use it during
monsoon and throughout the year. The public will see the difference and will appreciate
prompt and durable repair of potholes. I am ready to assist the government or private
agencies on a volunteer basis. With the availability of this mix, there is no excuse to use
18
th
Century technology for filling potholes on our streets and roads in India.

If you need more information on the preceding two important subjects of great public
interest, please feel free to contact me. I strongly believe we can get out of this “rut” of
potholes after potholes every year in India. Do you still have an excuse?

Prof. Prithvi Singh Kandhal
Jaipur
E-mail: [email protected]
20 August 2011


Post Script (25 September 2014)

After persistent efforts by the writer for the last 6 years, the Indian Roads Congress (IRC)
has finally adopted the so-called “Kandhal Mix” as a standard readymade pothole
patching mix with cutback bitumen. Hon. Nitin Gadkari, Minister for Road Transport and
Highways officially released the IRC:116-2014 Standard Specification on 19 August
2014 in New Delhi.

It is hoped this “idiot-proof” unpatented mix would now be used across India throughout
the year to tackle the menace of potholes. Specifications, rate analyses and “G” Schedule
used by the Jaipur Development Authority (JDA) for the past 4 years are attached for
including this mix in the Basic Schedule of Rates (BSR) and for calling tenders.

Rate analyses indicate patches made with the Kandhal Mix are more economical than
those made with hot mix asphalt because the latter is labor intensive (squaring the
pothole), material intensive (use of binder for tack coat), and equipment intensive (use of
roller). Patches made with this mix are also more economical and faster than those made
with the so-called automatic patching machines called by fancy names such as “road
ambulance” and “road doctor”. These machines require capital outlay and are also
difficult to maintain. Also, the cost of Kandhal Mix is about one-third the cost of many
patented readymade mixes such as Shelmac.







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ABOUT THE WRITER

Prof. Prithvi Singh Kandhal is Associate Director Emeritus of the National Center for
Asphalt Technology (NCAT) based at Auburn University, Alabama, U.S.A. NCAT is
the largest asphalt (bitumen) road technology center in the world.

Prior to joining NCAT in 1988, Prof. Kandhal served as Chief Asphalt Road Engineer of
the Pennsylvania Department of Transportation for 17 years. He is the first person born
outside North America, who has held the following three national and international very
prestigious positions in the asphalt road technology area:

 President, Association of Asphalt Paving Technologists (with members from all
continents in the world)
 Chairman, American Society for Testing and Materials (ASTM) International
Committee on Road Paving Standards (responsible for over 200 standards used
worldwide)
 Chairman, Transportation Research Board Committee on Asphalt Roads, U.S.
National Academy of Sciences

Prof. Kandhal has published over 120 technical papers and has co-authored the first ever
textbook on asphalt road technology, which is used by more than 25 universities in the
U.S. He has travelled to various countries in South America, Middle East, China,
Vietnam, Japan, Singapore, and Australia to provide training and consulting services in
asphalt (bitumen) technology. He has been to China three times to train their highway
engineers in building world-class roads.

Prof. Kandhal has been a practicing highway engineer in India for 20 years and in the US
for 30 years. Recently he has drafted many standards for the Indian Roads Congress
including specifications for dense graded bituminous mixes, stone matrix asphalt and
readymade pothole patching mix. He was also instrumental single-handedly in
introducing viscosity grading of bitumen in India in lieu of penetration grading in 2005.

In August 2011, Prof. Kandhal was inducted on the “Wall of Honour” established at the
largest asphalt road research center in the United States. In April 2012, he received the
“Lifetime Achievement Award in Asphalt Road Technology” from the International
Association of Asphalt Paving Technologists during their annual banquet held in Austin,
Texas, USA.








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JAIPUR DEVELOPMENT AUTHORITY, JAIPUR

Name of Work: Production and Supply of Kandhal Readymade Bituminous Pothole
Patching Mix to Zone Area JDA at Location (Godown)…………………………
(Rate Contract)

Schedule-G
S.N. Particulars Qty. Unit Rate to be
quoted
Amount
1.

Producing and supply of Kandhal
readymade cold bituminous
patching mix in 50-kg plastic
lined, sturdy bags for repair of
potholes in adverse climatic
conditions including the
bituminous mix with a minimum
of 5.6% MC-800 cutback bitumen
(containing a suitable anti-
stripping agent) by weight of mix
and in strict conformance to
gradation and other requirements
such as 6-month storage life as
per the enclosed specification
dated 1 February 2013; transfer
with all leads and lift complete in
all respects as per direction of
engineer-in-charge
[No.
of 50-
kg
bags]
50-kg
bag


Special conditions:
1. Specification for Kandhal readymade bituminous mix dated 1 February 2013 is
enclosed. Its strict compliance is required in production and supply. The
contractor shall be solely responsible if the mix is not workable and is not usable
for a period of 6 months for making durable patches.
2. All 50-kg bags shall be transported to a storage facility designated by the
Executive Engineer. Since the mix contains volatile kerosene, sealed bags shall
not be stored in a closed building or warehouse. Storage shall be made under an
open shed or in a well ventilated warehouse. No open flame or smoking shall be
allowed in the vicinity of the stored mix.


Executive Engineer
JDA, Jaipur


I/we agree to do the above work on rate as quoted above.

6
Indian Roads Congress Version as of
1 February 2013 for Rajasthan PWD and JDA

Specification for Kandhal Readymade Bituminous
Pothole Patching Mix


1. Scope

The material shall consist of plant mixed readymade pothole patching bituminous
mixture composed of mineral aggregate coated with bituminous material. The material
shall be capable of being stocked for at least six months without stripping and shall be
workable at all times. Unless specified otherwise, this mix shall be supplied in 50-kg
plastic lined, sturdy bags. This material is intended for patching potholes up to 75 mm (3
inches) deep. For deeper potholes, patching mix shall be placed and compacted in 75 mm
thick layers.

2. Materials

2.1 Bitumen

Medium Curing Cutback Bitumen MC-800 conforming to Indian Standards Specification
IS: 217 Specification for Cutback Bitumen shall be used in preparing the patching mix
and shall be supplied by a certified manufacturer of this product. For proper mixing, the
bitumen shall be heated as specified in Section 3.

MC Cutback Bitumen shall be treated with a proper type and amount of an anti-stripping
agent by the approved bitumen supplier so that when combined with the proposed job
aggregate the resulting mix shall pass the Wet Coating Test, Static Immersion Test and
Stripping Test as given in Annexure I. The antistripping agent shall conform to IS 14982.
The contractor shall furnish the sample of the job aggregate each year to the bitumen
supplier for these coating and stripping tests and obtain a certificate that the bitumen
material has been treated to suit the job aggregate. This yearly certificate must be on file
and shall be available at the asphalt mix plant when required by the Engineer. The
contractor shall also forward a copy to the Engineer. Under no circumstances, the
contractor or the department shall be permitted to manufacture the MC cutback by
blending paving bitumen and kerosene.

2.2 Coarse Aggregate

2.2.1 The coarse aggregate shall consist of crushed rock, crushed gravel or other hard
material retained on 2.36 mm sieve. It shall be clean, hard, durable and cubical shape,
free from dust and soft organic and other deleterious substances. The aggregate shall
satisfy the physical requirements specified in Table 1.


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2.2.2. Where crushed gravel is proposed for use as aggregate, not less than 90% by
weight of the crushed material retained on 4.75mm sieve shall have at least two fractured
faces resulting from crushing operation.




TABLE 1. Physical Properties of Coarse Aggregate

Property Test Requirement

Test method
Cleanliness Grain size analysis Max. 2% passing
0.075 micron
IS 2386 Part I
Particle shape Flakiness & Elongation
Index (combined)
Max. 35% IS 2386 Part I

Strength * Los Angeles Abrasion
Value
Max. 40% IS 2386 Part IV
Aggregate Impact Value Max. 30% IS 2386 Part IV

Durability Soundness (Sodium or Magnesium), 5 cycles
Sodium Sulphate Max. 12% IS 2386 Part V

Magnesium Sulphate Max. 18% IS 2386 Part V

Water absorption Water absorption Max. 2% IS 2386 Part III

* The coarse aggregate may satisfy either of the two strength tests.

2.3 Fine Aggregate

Fine aggregate shall consist of crushed mineral material passing 2.36 mm sieve and
retained on 75-micron sieve. It shall be clean, hard, durable, and free from dust and soft
organic and other deleterious substances. No natural sand shall be permitted.

2.4. Composition of Mixtures

When tested in accordance with IS:2386 Part 1 (wet sieving method), the combined
aggregate grading shall fall within the limits shown in Table 2. As far as possible an
aggregate with water absorption of 1.0 or less shall be used. The amount of residual
bitumen binder (total cutback bitumen minus diluent such as kerosene) in the mix shall be
as shown in Table 3. The readymade patching mix shall be rejected if it does not meet the
grading (especially the 0.075 mm sieve) and the minimum residual bitumen content. The
produced mix shall be tested by an independent approved testing laboratory before its
acceptance by the Engineer.

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Table 2. Gradation of Stockpile Patching Mix
Sieve size, mm Percent passing
9.5 100
4.75 40 – 100
2.36 10 – 40
1.18 0 - 10
0.075 0 – 2

Table 3. Minimum Residual Bitumen Content by Weight of Mix
Aggregate water absorption,
%
Minimum residual bitumen content,
%
Less than 1.0 4.5
1.1 to 1.5 5.0
1.6 to 2.0 5.5


Based on the characteristics of the aggregate and the performance of the mix, the
Engineer can specify amount of residual bitumen higher than that shown in Table 3.

The contractor shall ascertain from the supplier of MC-800 as to how much residual
bitumen it contains. For example, if the MC-800 contains 80% bitumen and 20%
kerosene and a total of 6.0% MC-800 is used by weight of the mix, the residual bitumen
content in the mix will be 4.8 percent.

3. Preparation and Storage of Mixture

The Kandhal readymade patching mix shall preferably be produced in a conventional
batch type hot mix plant. However, if a portable or stationary asphalt drum plant is used,
under no circumstances drying/heating of aggregates with a burner flame and mixing
with MC-800 shall be carried out simultaneously because MC-800 containing volatile
kerosene will catch fire and pose a safety hazard. The contractor and the engineer shall
ensure there is no open flame inside or outside the drum when MC-800 is added for
mixing.

The mix should be such that it can be stocked, handled, placed, and finished without
stripping of the bitumen from the aggregate. To help prevent stripping and avoid heat
buildup in a stockpile (which may burn the entire stockpile), the mixed material should
not be stockpiled no higher than 1.5 m for the first 48 hours. The stockpile then can be
raised in height and made conical in shape. Unless specified otherwise, the readymade
cold mix shall be placed and sealed in plastic lined, sturdy 50-kg bags on cooling.

The mineral aggregate should be clean and surface dry before mixing. The temperature of
aggregate and bituminous material should comply with those shown in Table 4.

9

Table 4. Temperature Ranges for Producing Stockpile Patching Mix
Bituminous material Aggregate temperature, C Bitumen temperature, C
MC-800 25 – 65 75 - 95


Since the range of aggregate temperature is rather low and the maximum aggregate
temperature is restricted to 65 C, it may not be possible to dry the aggregate within this
temperature range. Therefore, the aggregate can be processed in a dryer at high
temperatures and allowed to cool before the bituminous binder is added. Pre-drying the
aggregate at high temperatures will also help in reducing the fines (material passing 0.075
mm sieve), which will go into the baghouse. The resulting mix then would have fines less
than 2 % as required in the stringent gradation specifications.

High aggregate temperature while mixing with the cutback bitumen will not only
cause excessive loss of kerosene from the cutback but will also pose a safety hazard
in the plant pug mill. Proper and adequate venting of the pug mill is necessary.
Under no circumstances there shall be any open flame in the vicinity of MC-800
cutback because it contains volatile kerosene.

Since the mix contains volatile kerosene it is not safe to store the loose mix or sealed
bags in a closed building/warehouse. Store under an open shed or in a well
ventilated warehouse. No open flame or smoking shall be allowed in the vicinity of
the stored mix.


4. Quality Control and Acceptance of Mixture

The composition of the produced mix (gradation and bitumen content) shall be tested by
an independent, approved testing laboratory before acceptance by the Engineer. Before
conducting the bitumen extraction test to determine residual bitumen content in the
Kandhal patching mix, the sample shall be cured completely to remove all kerosene.
Curing shall be done as follows. Place the loose mix in an open metal container and heat
slowly on a hot plate with frequent stirring until a constant weight is achieved.

The following two tests shall be performed by the contractor (in presence of a
Department representative) on the mixture, freshly prepared or taken from a stockpile or
sealed bag at any time during its storage life (usually 6 months).

 Water Resistance Test (See Annexure I, Test C)
 Workability Test (See Annexure I, Test D)

The water resistance test would indicate whether the patching mix has a potential for
stripping in the pothole in presence of water. If the mix fails this test, it means a proper
type and/or amount of an antistripping agent has not been used in the bituminous binder.

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If the mix fails in workability it could be due to improper bitumen type, low bitumen
content, excessive fines or improper gradation. Even one-half percent lower bitumen
content can make the patching mix unworkable and useless.

Stocked patching material may be rejected, at any time during the six month period if, in
the opinion of the Engineer, the patching material has stripped (more than 10% uncoated
particles) or otherwise become unfit or unworkable for use.


5. Measurement for Payment

The tonnage of the Kandhal readymade pothole patching mix shall be measured and
determined from the actual plant batch reports as recorded by a representative of the
Engineer assigned to the work. In case the Kandhal mix is supplied in plastic lined,
sturdy bags, each bag must weigh at least 50 kg and the number of bags shall be counted
for payment.


6. Rate

The Kandhal readymade bituminous patching material shall be paid for at the contract
unit price per ton or per 50-kg bag, FOB the asphalt mix plant, at the work site, or at
other destination as specified in the contract. A reasonable amount of earnest money will
be kept by the Department for 6 months or on depletion of the stockpile, whichever is
earlier, to ensure the product is satisfactory for use and meets all tests specified earlier
during the life of the product.


ANNEXURE I

A. Wet Coating Test

Heat the unwashed job aggregate, cutback bitumen and distilled water to 40 C in a
suitable oven. Weigh 100 g of dry aggregate into a suitable mixing container (such as
seamless tin can, 16 oz capacity). Add 3 ml of distilled water. Mix thoroughly with a
spatula until the aggregate particles are uniformly wetted. Add cutback bitumen
equivalent to 5.0 +/ 0.2 g of bitumen residue. Mix rigorously with the spatula until all
aggregate is coated, but not more than 5 minutes. Transfer the contents into a 400 ml
beaker containing 150 ml of distilled water (22 – 32 C). Let stand for 15 minutes and
visually determine the percent of retained coating, which should be at least 98 percent.

B. Static-Immersion Test

The coated aggregate as prepared in the preceding wet coating test shall remain immersed
in the beaker of distilled water (22 – 32 C) for 24 hours. At the end of this period,
visually determine the percent of retained coating while the sample remains immersed in
water, which should be at least 95 percent.
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C. Water Resistance Test

Fifty grams of patching mix, whether freshly prepared or taken from the stockpile or a
sealed bag, shall be heated at 120 C in a laboratory oven for 1 hour, cooled to 95 C in
laboratory air, and then placed in 400 ml of boiling water in a 600-ml glass beaker and
stirred with a glass rod at the rate of 1 revolution per second for 3 minutes. The water
shall be decanted and the mix shall be spread on an absorbent paper for visual
observation of the coating. The aggregate shall be at least 90 % coated with a bituminous
film.

D. Workability Test

Approximately 2.5 kg of the patching mix shall be cooled to –7 C in a freezer. After
cooling, the mixture shall be capable of being broken up readily with a spatula that has a
blade length of approximately 200 mm. This test shall be performed when the mix is
produced and thereafter anytime during storage. If the mix is not workable at –7 C, it
shall be rejected and the composition of the mix shall be properly modified (for example,
by increasing the bitumen content and/or gradation changes). This test is also applicable
in areas with hot climate because it amplifies the workability characteristics of the mix by
using a lower test temperature.

**************************************



JAIPUR DEVELOPMENT AUTHORITY, JAIPUR

Name of Work: Placing and Compacting Kandhal Readymade
Bituminous Patching Mix in potholes on various roads in Zone…..
Area JDA, Jaipur (Rate Contract)

Schedule-G

S.N. Particulars Qty. Unit Rate to be
quoted
Amount

1.


Placing and compacting Kandhal
readymade cold bituminous
patching mix in potholes in
adverse weather as per enclosed
specifications including cleaning
of potholes; placing and
compacting the mix; sprinkling
sand to prevent pick up by traffic;

[No.
of 50-
kg
bags]

50-kg
bag

12
and documentation of patches,
with all leads and lifts complete in
all respects as per attached
specifications and direction of
engineer-in-charge.

Special conditions:
3. Specification for placing and compacting the Kandhal readymade bituminous mix
dated 1 February 2013 is enclosed. Its strict compliance is required.

Executive Engineer
JDA, Jaipur



I/we hereby agree to do the above work on rates as quoted above.



Signature of the Contractor
With full postal address and Mobile Number



**********************************************************************


Indian Roads Congress Version as of 1 February 2013


Specifications for Placing and Compacting Kandhal Readymade Cold
Bituminous Mix in Potholes


1. Scope

These specifications cover placing and compacting the Kandhal readymade patching
mix in potholes including transportation of the mix from the designated storage
facility to road sites as directed by the engineer. The work involves cleaning and
preparation of potholes; placing and compacting the mix; applying sand to prevent
pick up by traffic; and documenting the number and sizes of the patches. The
Kandhal readymade cold patching mix is suitable for patching “potholes” only and
shall not be used for patching long stretches of deteriorated road surface.


2. Preparation of Potholes
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Pothole shall be cleaned with a stiff wire brush and all loose material including dust
shall be removed with a soft brush. Pothole need not be dry. However, excess water
shall be swept off the pothole.

If the pothole is deep and extends to WMM or granular base, it is recommended to
apply a prime coat consisting of MC-30 Cutback before placing the patching mix. If
angular aggregate (nominal size 25 mm) is used to partially fill deep potholes, the
aggregate should be compacted thoroughly and primed with MC-30 before placing
the patching mix. At least 50 mm thick pothole patching mix shall be placed at the
top.

3. Placing Kandhal mix in Potholes

The Kandhal mix is intended for patching potholes up to 75 mm (3 inches) deep. For
deeper potholes, patching mix shall be placed and compacted in 75 mm thick layers.

Sufficient material shall be placed in the pothole so that after compaction the patch is
about 10 mm above the existing road surface.

4. Compacting the Kandhal mix

First the outside edge or periphery of the patch shall be compacted with a hand
rammer and then compaction shall proceed inwards. To prevent initial pick up of the
loose mix by the hand rammer either continue to wet the hand rammer with water or
place empty plastic lined bags on the loose mix.

For deep potholes, place the patching mix and compact in 75 mm thick layers. After
compaction, the compacted patch shall be about 10 mm higher than the existing road
surface to allow for further compaction by traffic.

If there are numerous closely spaced patches, it is preferred to use a small roller rather
than a hand rammer.

5. Applying Sand to Prevent Pick up by Traffic

Before opening the compacted patch to traffic, sufficient amount of clean sand shall
be sprinkled on the patch to prevent pick up by traffic.

6. Documenting the Number and Sizes of Patches

The contractor shall document and the engineer shall verify the following on a daily
basis: (a) Number of 50-kg bags used; (b) Name of road and chainages where patches
were made; and (c) Average sizes of potholes patched by measuring their average
length, average width and average depth.

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7. Measurement for Payment

The total number of 50-kg bags of Kandhal mix placed and compacted by the
contractor shall be recorded by the engineer for payment. Payment shall be made at
the contract price per 50-kg bag.

***********************************



Cost Analysis of Supplying Kandhal Readymade Bituminous Pothole Patching Mix
to Department Godown
(Revised 16 March 2013)


Assume one ton (1000 kg) of the mix is to be made and filled in 20 bags of 50 kg each,
which will be supplied to Department Godown for use later.

A. Cost of Materials

1. Aggregate of specified gradation; rate of Rs. 300/ton;
Add extra cost 10% for special size; total rate is
Rs. 330/ton
Aggregate 940 kg @ Rs. 330 per ton………………………………….. 310.20

2. Bitumen MC-800 Cutback supplied in drums:
60 kg @ Rs. 60,000 per ton……………………………………………. 3600.00

3. Anti Stripping Agent @ 0.3 % by weight of MC-800
1.8 kg @ Rs. 165 per kg…………………………………………………. 297.00

Total for A 4,207.20

B. Production Cost

1. Portable Mini Hot Mix Plant with capacity of 8 tons/day
Rent for one day = Rs. 1000. Rent to produce one ton will be
one-eighth of Rs. 1000, that is, Rs. 125………………………………… 125.00

2. Fuel costs: 24 liters per day; 3 liters per hour
3 liters @ Rs. 50 per liter……………………………………………… 150.00

3. Labour: 8 labourers needed per day to produce 8 tons
1 labourer needed per ton @ Rs. 300 per day…………………………. 300.00


15
Total for B 575.00

C. Packing, Handling and Transport to Department Godown

1. Cost of 50-kg empty bags
20 bags @ Rs. 12 per bag……………………………………………….. 240.00

2. Labour for filling, weighing and sealing bags;
3 labourers can fill 160 bags in one day (20 bags in one hour)
Cost of labourers for one day = 3 times Rs. 300 = Rs. 900
Cost of filling 20 bags in one hour = 900/8…………………………….. 112.50

3. Transport of bags from plant to department godown
(average 10 km lead) 1 ton@ Rs. 200 per ton…………………… ……. 200.00

Total for C 552.50


D. Total of A + B + C……………………………………………………. 5,334.70

Contractor’s overhead @ 10% of D........................................................... 533.47

Royalties, sales tax, income tax etc. @ 4.5% of D....................................... 240.06

Total 6,108.23

Add 10% contractor’s margin……………………………………… 610.82

Total Cost per ton (20 bags of 50 kg each)…………………………..Rs. 6,719.05

Cost per kg……………………………………………………………..Rs. 6.72

Cost per 50-kg bag……………………………………………………..Rs. 335.95


Revised 16 March 2013










16
Cost Analysis of Laying Kandhal Readymade Bituminous Pothole Patching Mix
(As of 16 March 2013)


Assume Eight (8) tons of the Kandhal mix will be laid
in potholes in one day. Costs for one day operation are as follows:

1. 4 Labourers @ Rs. 300 each…………………………………… 1,200.00

2. Transportation of bags from Department Godown to
laying site (average one-way lead of 20 km)
(a) Rent of tractor = Rs. 600
(b) Cost of diesel = Rs. 400 (tractor will consume one liter
per 5 km; 8 liters for 40 km @ Rs. 50 per liter = Rs. 400
Total transportation cost = 600 + 400 = 1000…………………… 1,000.00

3. Sand bags for sprinkling sand on patches to avoid pickup:

2 sand bags @ Rs. 10 per bag………………………………………20.00

Total 2,220.00

Add 10% contractor overhead……………………... 222.00

Add 4.5% for royalty, sales tax, income tax, etc……………….. 99.90

Total 2,541.90

Add 10% contractor margin…………………………………….. 254.19

Total 2,796.09

This is the cost for 8 tons.

Cost per ton = Rs. 349.51
Cost per kg = Rs. 0.35
Cost per 50-kg bag = Rs. 17.48

(As of 16 March 2013)