Cement a good additive for durable economical …icipunecentre.org/papers/20-P L Bongirwar.pdf · Cement a good additive for durable economical Road Construction P L Bongirwar Consultant

Cement a good additive for durable economical Road Construction

P L BongirwarConsultant.

M Tech, FNAEFormer Principal Secretary PWD, GOM

172ARKEY CONFERENCE SERVICE CELL, PUNE

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AbstractCement has potential use for durable and economical road pavements and can reduce recurring maintenance cost. It can be used in different components of road structure. Lifecycle cost analysis justifies cement roads for all categories of roads. The traffic on road vary from 5 commercial Vehicles per day to 10000 CVD per day and technologies for economical construction using cement for such varying traffic conditions are now available..Good quality aggregate or soil for large part of country is not available in economical leads hence the properties of the locally available materials need to be improved using cement. The paper describes various techniques of road construction pavement where cement can play an important role for economical durable roads. Pavement with Cemented base can reduce cost by 25%.Cement stabilized soil is a proven technology. Jointed concrete road pavement, continuous reinforced concrete pavement, short paneled concrete and precast prestressed panel concrete technology described in paper can give several option for economical construction.echnologies. Cement grouted bituminous mix can give pothole free and durable roads not only for urban areas but also for medium volume traffic roads. Shell field technology, and optimally designed self compact concrete using HDPE strips are the technologies developed for new low volume village roads. Reviving badly damaged village roads using grouting technology and substituting liquid seal coat with grout seal coat are few cost effective options for village roads

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1.0 INTRODUCTION - Cement is one of the oldest,

economical and popular additive to bind the natural

material as aggregate sand etc Modern development

would not have been possible if the cement would not

have been invented. The cement is extensively used in

building construction as well as bridges. It has a

tremendous potential for construction of roads. However

usage of cement may be hardly 15% of total

consumption. Due to development of various

construction equipment like high capacity crusher,

computerized controlled RMC plant, Slip Form paver

various types of admixture the techniques of usage of

cement for construction of roads has substantially

changed. It is now possible to develop concrete of

desired properties ie high strength, high early strength,

self compacts concrete,pumpable concrete etc.One

more advantage of use of cement for road construction is

that we can have more durable roads requiring least

maintenance. The differential cost of concrete roads and

bituminous road is gradually getting reduced due to new

additives ,equipment etc Life cycle cost for concrete

roads compared to flexible roads is much less

2.00 Pavement options-In last few years few

technologies are getting introduced. The total road length

may be about 50 lakhs out of which low volume roads ie

village roads may be 35 lakhs Depending on the traffic

intensity and availability of funds appropriate road

construction technology is adopted However amongst

all options the usage of cement gives durable pavement

requiring least maintenance cost

It is interesting to know advantages in terms of cost

and material saving for each of them so that proper

decision can be taken. The same is given in different

table

3.0 Flexible Pavement -The traditional flexible

pavement consist of subgrade,GSB,WMM ,DBM and BC

as wearing coat By adopting stronger lower layers i.e.

sub grade of 15% CBR to be obtained by cement

stabilisation,cemented sub base or higher grade of

bitumen cost can be reduced and material consumption

also can be brought down The large part of country is

covered with soil having low CBR value.A properly

designed stabilize soil sub grade of alluviam soil using

about 1% cement can produce material of 10 % CBR

which can reduce cost and material consumption. Poor

subsurface drain is the main cause of damage to road

pavement .Cemented drainage layer has permeability of

350m/day against 20m/day with traditional GSB.Higher

MR Value of this layer would reduce the cost on

bituminous layer and we can get more durable pavement

at reduced cost

3.1 Composite Pavement - In several countries

specially South Africa there is tremendous shortage of

good aggrgatte.The concept of cemented base and sub

base are very common in these countries

The pavement composition wit cemented base and /or cemented subbase can reduce cost ,material

consumption and imported bitumen requirement.

Table 3.1 Use of cement for Base and Subbase

3.2 Cement grouted bituminous mix - Incidences

of pot whole formation in urban areas especially during

monsoon is much more. Inadequate bitumen content,

poor quality control, poor subsurface drainage, inability to

maintain mixing and compaction temperature resulting

into improper compactions are few reasons for this.

Another major cause is the frequent braking action

creating heavy tractive force.The analysis has shown

that the heavy tyre pressure create a transverse tensile

force which perhaps in the cause of leakage of water and


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thus damaging the road We have not so far succeeded in

finding an effective solution. Adoption of concrete roads,

mastic asphalt, panelled concrete and paver block

wearing coat has been successfully tried. The technology

of cement grouted bituminous mix consisting of 3.5%

voided bituminous macadam which is grouted with high

strength grout of 40 Mpa strength which improves the

property of composite and perhaps would give cost

effective alternate

1) Traditional wearing coat of 50 mm BC

550Rs per square meter

2)Mastic asphalt

700 Rs per square meter

3) Paver laid Mastic


4) Concrete top surface


5) Panelled Concrete


6) Paver block wearing coat


7) CGBM

540 to 610 Rs per square meter

It will be thus obvious that in the same cost we can give

much durable surface The detailed IRC guidelinesare

being isued soon.The tehnology is quite cost effective for

traffic upto 30 MSA and also for renewal coat..The

technology is ideal for urban roads where 80% of road

length carry traffic less than 30 MSA and commercial

traffic is much less.

4.0 Categories of Concrete Roads

Concrete road pavements have been generally

acceptable by public due to its reduced maintenance

problems. Of course the riding quality in concrete surface

is not comparable to bituminous road and it causes more

noise due to movement of vehicles. Due to slightly higher

friction coefficient there are reported case of tyre bursting

due to high speed drive and on account of use of old worn

out tyres.However in urban as drainage conditions are

poor, there is much higher incidence of applying brakes

which causes much damages to bituminous roads and

hence concrete roads are preferred n urban area. The

general speed of vehicles in urban area is much less

hence incidence of tyre bursting or noise pollution is

virtually absent. In recent years there is much

improvement in the technology which is adopted in

developed countries and should be encouraged in our

country. Some of these technologies are described

below. Some of these deficiencies can be removed

through more applied research as explained below

4. 1 Continuous reinforced Concrete Pavement -

IN CRCP the joints are spaced a 10 to 15kilometer hence

riding quality gets much improved. It is possible to

provide bituminous overlay on this which will further

improve the riding quality and incidence of tyre bursting

also would be absent

CRCP 3025 Rs per Square meter Concrete Jointed

Road 3070 Rs square meter

AASHTO has recent ly publ ished h ighly

sophisticated software to account for various

conditions which affect the performance and

behavior of CRCP to help engineers to evolve cost

effective design Thickness is function of designed

life, loading pattern, climatical condition, support

condition, steel quantity, location of steel etc

4. 2 Paneled Concrete/White topping - In this

technology the strength of supporting base. sub base


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is ascertained and top concrete overlay is laid of

appropriate thickness. The thickness of concrete overlay

is function of traffic and strength of base. In this

technology the joints are closely spaced up to 1.5 m

hence the temperature stresses are virtually absent

which results into much lesser thickness. Presently this

technology is extensively applied in urban area and also

for low volume roads. However this can be adopted for

roads carrying heavy traffic and also for the new roads.

For the Bangalore ring road carrying about 10000 CVD

this has been adopted. A scientific performance study of

this stretch be done. Cost of paneled concrete if adopted

for new road may prove less than that of flexible

pavementThis is adopted for Shivaji Nagar Bus stand

approach road in Pune

Cost of Panelled Concrete


Cost of Flexible Pavement

!927 Rs per square meter

4.3 Development of guidelines for use of pre-

cast panels for highway pavements –

Technology of use of precast presntesoned panels

have been developed and adopted. It allows good

quality concrete, reduction in materials and also fairly

good riding quality


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5.0 Technology for village road - The following

technologies are proposed which can partly address the

objective of creating durable assets at affordable cost i.e.

concrete roads at optimum cost., Extensive lab study has

been done and theoretical analysis done to satisfy the

adequacy of crust and then few trial stretches completed.

The three technologies for village roads are

A) For new roads

1) Shell fil led concrete developed by Prof

Pande, IIT Kharagpur India

2) A d o p t i o n o f o p t i m a l l y d e s i g n e d S e l f

compact concrete.

3) Cement grout seal coat in conventional

20mm carpet

B) For existing badly damaged metalled road

1) Paneled concrete to be formed using

grouting technology

5.1 Shell filled concrete low cost technology for

villager road - Prof Pande of IIT, Khargpur has

developed this technology and has carried out several

experiments with different option. Practical trials in lab

and field have been done. Several kilometers of village

roads have been constructed and are performing well.

5.1.1 The technology consists of covering the

compacted sub grade/sub base with a form work of

plastic cells of 200 micron of 150 mm x 150mm size as

shown in fig 4.1 The formwork of plastic cells are

stretched and iron spikes are driven at the corners of the

cells so that the formwork remains taught

5.1.2 Grouting shells- As an alternate to above the plastic

shells can be filed with loose small size aggregate and

the whole mass can be grouted using appropriate mix

the formwork of cells are spread over the compacted sub

grade/sub base and kept taught .The cells are uniformly

filled with single size aggregate and rolled with a static

roller. Cement sand slurry mixed in the ratio of 1::1 by

weight is vibrated into compacted aggregate by plate

vibratory or with static roller. Cement should be mixed

with water first and then sand should be added for making

slurry.

Fig 5&6: Cells filled with single size aggregates

(compacted with a road roller)

Fig 4.1-Laying of formwork of plastic cells

Fig. 2- Placing of zero slump concrete into cells


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5.2 Optimally designed self compact concrete

5.2.1 Selection of ideal construction technology-Self

Compact concrete – Self compact Concrete for village

roads is strongly recommended in view of least

requirement for vibration and ease to get good dense

compact concrete in line and level by using simple

screed. Extensive use of fly ash to meet objective of

powdery content, special ad mixture to reduce water

cement ratio and get desired flow has helped in

developing cost effective concrete mix having cost of

cenmentitious and additive less than 1900Rs per cubic

meter Joint cutting and filling of joint is eliminated by

HDPE strip which are stressed by special tool developed

has helped to bring the differential cost to less than 4.5%

compared to bituminous surface Total investment in

simple equipments which can be operated in remote

areas is not likely to exceed 9 lakh which ensures a

quality job at least cost. Following photographs explains

the technology.

5.3. Equipment- The total investment in simple

equipment may not exceed 9 lakh consisting of concrete

mixer, simple screed, and plate compactor channels and

stressing tools to get an output of 80 to 90cubic meter per

day and thus bring down the cost of owning and major

maintenance of equipment to less than 30Rs per cubic

meter

Fig 12: Mixer and Paver Equipments

Fig 13: Common equipments and local labor to

produce optimally designed self compact concrete

5.2.3 Nasik Trial (2013)-A small stretch along NH 4 in

Nasik city is done which will serve as bus bay at later

date. Photographs showing preparatory work, stressing

device and anchoring system Special stressing device

was developed

Fig 14: Photographs showing preparatory work,

stressing device and anchoring system

5.2.4 Cost optimization with self compact

concrete - The cost effective optimally designed self

compact concrete is having cost of cementious material

as 1900 per cubic meter and hence would reduce cost

unit cost of final production. Table2. 1 gives other options

of cost reduction. Elimination of process of joint cutting

and adoption of HDPE strip reduces initial and recurring

maintenance cost. Of Adoption of simple equipment with

low capital investment has reduced cost of final product

SCCC has reduced the labour component substantially.

5.3Cement grout seal coat in conventional 20mm carpet-

-For PMGSY road wearing coat consist of 20mm carpet

plus liquid or premix seal coat .The average cost

worksout to 210 Rs per square meters. The standard


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specification have suggested gradation consisting of 2/3

material passing through 22.4 mm sieve and fully

retained on 11.2 mm sieve For one third material the

gradation proposed is s passing 100% through 13.2 mm

sieve and fully retained on 5.6mm sieve .Prof Pande

carried out few experiment wherein he adopted 100%

material passing through 22.4 mm and fully retained on

11.2mm Thus the finer particle were total omitted creating

more voids. Further instead of liquid seal coat cement

grout seal coat is done.Speccially designed grout was

adopted as stated in Para Photograph are attached We

have also done similar experiment in Amravati district in

march 2014.(Photographs attached)Even after two

monsoon the surface is in good condition It is observed

that the total cost of carpet plus conventional seal coat

and this alternate technology the incremental cost is less

than 5% but as it will improve the durability the additional

price is worth paying, Research has proved that

reduction in bitumen content and properly designed grout

improves the properties Research therefore has been

intuited in this direction. In this technology the

conventional equipments are used hence the adoption in

field is convenient

Photographs showing production of cement gout and its

application to voided 20mm carpet

6.0 Paneled concrete for existing badly

damaged metaled roads

6.1 Paneled concrete/-White topping technology

consisting of small paneled concrete up to 1m having

thickness 100 to 150mmfor laid over existing damaged

bituminous roads has received public acceptability as it

can give maintenance free roads. Admixtures such as

steel fibers to get higher flexural strebgth,plastic to

reduce shrinkage cracks and reduce abrasions, special

additives recently developed to get high strength up to

m60 in one day which allows opening of roads in 24 hours

are few innovations making this technology most

economical and popular

Fig 8: Typical photos of Thin white topping for Thane

6.2Grouting technology-For low volume roads-

Fundamental principle of above technology of deciding

the thickness of concrete overlay noting the panel size,

traffic ,grade of concrete and strength of supporting

bases is proposed to be made use in reviving badly

damaged medaled roads in the most economical way


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Damaged metaled roads-More than one lakh in

Maharssdhtra

Presently it is a practice to put one to one and half layer

metal to bring the surface in proper camber followed by

carpet and seal coat which cost about 220 Rs per square

meter but such a road again requires renewal after every

five years for which Govt is not able to make adequate

budgetary provisions. As an alternate to this grouting

technology is developed using special admixtures .the

procedure is explained in figure below

a)Shells to be filled with hand broken metal of

proper gradation and it camber

b) Loose aggregate will be compacted

c) The entire surface to be grouted by specially

developed low viscous grout or with concrete

technology

d) Final Camber and line and level to be

achieved by using screed

Photographs of Trial strech

6.3 Development of Highly Flow able Grout-Real

challenge is developing highly flow able grout which will

flow in all voids and ultimately give actable uniform

surface. Due to using effective admixture free flow grout

at affordable cost was developed

Cost of grout is 5600 rs Per cubic meter for M30 and 6100

Rs per cubic meter for M40 to give strength of M60 and

core stregth of M30/M40

and few trials were successfully done WE could

6.4 Ecnomics - Depending upon the traffic intensity

and sttrength of damged metaled road to be assesd by

Benkalmen Beam the thickness of “grued layer” or

Whitetoping can be adjusted By slecting the grade cof

concrete andsize of shell the cost can vary from 200 Rs

per sq m to 260 Rs per square meter.This can prove an

ideal cost effective solution for internal roads of colony

CONCLUSION - Cement can prove a very good

additive to construct more durable cost effective roads of

different categories Several techniques are now

avaolable.The present techniques can be made more

cost effective due to intorduction of new additives, new

equipment and more applied research


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References1) Prof B.B. Pandey, IIT Kharagpur, Low Cost Concrete Pavement,

2)Prof B.B.Pandey IIT Kharagpur March 2008. “Durable Pavements for Village Road with Sand Cement”, in Pradhan

Mantri Gram Sadak Yojna , Grameen Sampark,

3)Subrata Ray et al June 2010. “An Investigation on Cell filled pavements”, Department of Civil Engineering, IIT, Khargpur,

Journal of Pavement Engineering,

4) Analytical Design of Short Panelled Concrete PavementsArunChand,M.V1. and B.B.Pandey2

5) Drivels Deshmukh consultant ACCCL June 2011 UTWT for eco-friendly roads by, Construction Business today VOL

NO1 No3.

6) V.K.Sinha, Santander kumar and R.k.Jain.WHITE TOPPING a Cost effective rehabilitation alternative for processing

bituminous pavements on long term basis

7) DURABLE ASSETS FOR VILLAGE ROADS AT AFFORDABLE COST

P L Bongirwar 1, M Tech, FNAE, Published at seminar held in Augut 16 at IIT,Roorkee on occasion of completion of 25 Years

to PMGSY


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Cement a good additive for durable economical …icipunecentre.org/papers/20-P L Bongirwar.pdf · Cement a good additive for durable economical Road Construction P L Bongirwar Consultant