CONCRETE PAVEMENTS : HIGHWAYS TO

PROSPERITY

By

Binod Kumar

Head & Pr. Scientist

RP Division

CRRI

GOOD ROADS : A FUNDAMENTAL RIGHT !

On a PIL regarding

accidental deaths due

to pot holed roads,

Hon’ble High Court of

Maharashtra observed

that this is the right

time for all concerned

to understand that

‘Right to Good Roads’

is a part of

Fundamental Rights of

Indian Citizens (20th

May, 2015)

WHICH ROAD IS A GOOD ROAD ?

Serviceability

Durability

Cost Effectiveness

Least Damage to Environment

WHY CONCRETE ROADS ?

DURABILITY AND MAINTENANCE

• Concrete highways are far more durable than other

pavement types

• Design life is normally 25-30 years but actual service life

may be more than the design life

• Do not require any major maintenance during service life

• India spends nearly 70% of the annual road sector budget

(Rs.30,000 Cr.) only on the maintenance of bituminous roads

which is a huge wastage of tax payer’s money

Marine Drive CC Road

(Mumbai)- First

Constructed in 1939

Re-constructed as CC

Road in 2012 after

more than 70 Yrs.

CONSTRUCTION AND MAINTENANCE COST

• Initial construction cost 10-15% higher than

bituminous road

• 25-35% cheaper in life cycle cost

• Almost maintenance free. Only joint resealing is

required once in 5-6 years

FUEL CONSUMPTION

• Large deflections of flexible pavement under load

due to visco-elasticity

• Very less deflections of rigid pavements

• Thus, rolling resistance of rigid pavements less

resulting in reduced fuel consumption

FUEL SAVING STUDIES

• CRRI – CMA (India – 1997) Study – 14 % Less for Heavy

Loaded Trucks

• Swedish National Road & Transport Institute (Four Axle

Trailer-2010) – 6.7 % Less

• University of Texas at Arlington for city Driving (Light

1360 kg Van – 2010) – 3 to 8.5 %

• Other Global studies show that fuel consumption of heavy

vehicles is 10-15% less on concrete highways

WHAT DOES FUEL SAVING MEAN FOR US ?

• Two lane carriageway length - 100 km

• Fuel consumption of truck @ 5 km/l = 20 Liters

• Truck traffic – 4500/day

• Annual Fuel consumption = 32850000 liters

Fuel Saving Annual Cost of

Saving @

50/L, Rs

Construction

Cost 2 Lane,

300 mm, Rs.

Pay-Back

Years

5 % 8.21 Crore

204 Crores

25 years

10 % 16.4 Crore 12.5 Years

14% 23.0 Crores 9 Years

• Total length of NH – 1,00,000 km

• Present Loss – Rs. 8210 Cr. (5% Fuel Saving)

– Rs. 16400 Cr. (10% Fuel Saving)

ENVIRONMENTAL IMPACT OF PAVEMENT CONSTRUCTION (2 Lane Per Km)

GREEN HOUSE GAS EMISSION OF RIGID AND FLEXIBLE

Methods CO2 Emitted (in Tonne CO2 eq)

Rigid Pavement Flexible Pavement

Embodied Energy

1246 95

During construction

6.6 84

Material Transport

46.7 40.7

Total 1299.3 219.7

• CO2 eq due to 5% Fuel Saving – 1372 T in 30 Years

TYRE BURSTING ON EXPRESSWAYS

• Sudden Release of Tyre Inflation

Pressure

• Inflation Pressure > Tyre Strength

• Temperature rise of Tyres during

Travelling

IS ROAD SURFACE FRICTION RESPONSIBLE FOR TYRE HEATING ?

• Possible External Source of Heating

• Rolling Friction:

Coefficient value - 0.01 to 0.015 (tyre-concrete)

0.01 to 0.020 (tyre-asphalt)

•Sliding / Kinetic Friction:

Coefficient value - 0.6 to 0.85 (tyre-concrete)

0.5 to 0.80 (tyre-asphalt)

• Road surface temperature:

Ambient Temperature (45°C) - 57°C (concrete)

70 °C (asphalt)

• Ambient temperature

• Thermal conductivity, W/m°C: 0.293 (rubber), 1.719 (Concrete)

FLEXING OF TYRE : TRUE CAUSE OF HEATING

• Deformation of Side Walls

• Hysterises loses in Rubber and Steel

Wire Beads leads to Heating

•Continuous built up of heat at

sustained high speed weakens the bond

of steel wire and rubber, increase

pressure and eventually tyre bursts

•Pressure increase – 1.6 psi/10°C

Flexed Tyre

Un-flexed Tyre

FACTORS INFLUENCING FLEXING

• Vehicle Speed:

Higher the speed higher the flexing & heating

Typical Maruti Swift tyre flexes per minute:

- 620 at 60kmph

- 1240 at 120 kmph

- 1550 at 150 kmph

• Tyre Pressure:

Low pressure – more flexing & heating

High pressure – less flexing & heating

• Load on Tyre:

Higher load – more flexing & heating

Lower load – more flexing & heating

LOAD-SPEED-TEMPERATURE RELATION(Yeong & Hwang, 2004, Taiwan)

Pressure = 30 psi

Load

Speed

4 KN

(Swift + 2)

6 KN

(Innova + 2)

8 KN

(Innova + 8)

40 kmph 60 °C 65 °C 70 °C

60 kmph 70 80 90

80 kmph 90 100 110

100kmph 105 120 130

120 kmph 120 135 155

Tyre Temp. : 100-110 Safe

140-150 Critically High with 80 % Probability of Bursting

160-170 Burst

CONTINUOUSLY REINFORCED CONCRETE PAVEMENT (CRCP)

• No joints & joints related

problems

• Thickness same as for JPCP

• Better riding quality

• Almost zero maintenance

• Longer life of more than 40 years

• Initial cost higher by 25 % than

JPCP

• 30 – 40 km length constructed in

Pune city

TWO LIFT CONCRETE PAVEMENT

• Two concrete layers placed wet-on-

wet within 30-60 minutes

• Top layer (50-100 mm) of good

quality concrete (M40) with good

quality aggregates

• Lower layer (200-250 mm) of lower

strength concrete (M20-M30) with

inferior quality aggregates –

marginal, recycled, C&D

• 28% saving of cement hence cheaper

• Common practice in France,

Germany, Austria, US

• IRC code under preparation

SHORT PANELED CONCRETE PAVEMENT

• Suitable for both whitetopping and

new rigid pavements

• Slab / panel size – 1m x 1m

• Dowels only at construction joints

• Lower bending and curling stresses

• 300 mm conventional thickness can

be replaced by 200-220 mm with short

panel size

• Design as per IRC:SP:76

•NICE road in Bangalore as

whitetopping

SOME IMPORTANT CC ROAD PROJECTS IN

INDIA

165 km long access

controlled eight lane

expressway between

Delhi & Agra, 2012

95 km long access

controlled six lane

expressway between

Mumbai & Pune, 2002

Thin White Topping, 180

mm, on Pune City Roads,

2013

Thin White Topping, 200

mm, on Bangalore Ring

Road, 2013

Thank You

CAIRO – SUEZ CC ROAD : 2016

(EGYPT)