Pervious pavement

1. PERVIOUS CEMENT
CONCRETE
PAVEMENT
when it rains it drains….
Submitted to: Dr. Kanish Kapoor

2. Pavements
 Road transport is considered to be one of the cost-effective and
preferred modes of transport for both freight and passengers.
 India has an extensive road network of 4.24 million km– the
second largest in the world.
 The National Highways have a total length of 70,934 km and
serve as the arterial road network of the country.
 While Highways/ Expressways constitute only about 2 percent of
the length of all roads, rest are state highways, major district
roads, district roads and rural and other roads, which are
considered as low volume roads.
 Rural roads consist over 85 percent of the road network.

3. Pervious vs Impervious pavement
Pervious concretepavement
Impervious concrete
pavement

4. Pervious pavement
 Pervious pavements are designed to infiltrate
stormwater, reduce peak flows and promote
groundwater recharge.
 Pervious pavement systems consist of a surface
with joints and/or openings that will freely allow
water to infiltrate the system.
 On an average, it can take 36,000 mm water per hour.
 The level of water absorption may vary from country-
to-country based on its climatic conditions.
 It can take more than 100-year storm and even if it
gets blocked with dirt, it can absorb 95 per cent of the
water.

5. Applications of pervious pavement
 pervious concrete pavement is mostly used in low
volume low speed roads, with personal vehicle at
a speed 50 km/hour or less.
 Such examples for its application includes:
• Sidewalks
• Parking lots
• Walkways
• Driveways
• Shoulders
• Residential Streets

6. Contd.
CAR PARKINGS SIDE
DRAINS

7. Types of pervious pavement
 Pervious cement concrete pavement.
 Pervious asphalt concrete pavement.
 Porous paver block.

8. Pervious cement concrete
pavement.
 A mixture of coarse aggregate, Portland cement,
water and little or no sand.
 Controlled amounts of water and cementitious
materials creates a paste that forms a thick coating
around aggregate particles without flowing off
during mixing and placing
 Has a 15-25% void structure, hence lightweight.

9. Materials
 Portland cement
 Coarse aggregate
 Water
 Cementitious material
 admixture

10. Materials Proportions
Cementitious materials 270-415
Narrowly graded aggregate
(gravel/crushed stone)
1190-1480
w/c ratio 0.28-0.35 (with chemical admixtures)
0.34-0.40 (without chemical
admixtures)
Cementitious materials/Aggregate
ratio
1:0.21-1:0.25
Fine aggregate: Coarse aggregate
ratio
0 to 1:1
Polypropylene fiber (optional when
no fine aggregate is present)
0.1% by volume or 0.9 kg/𝒎 𝟑

11. Properties
1. Gradation of aggregate
 Aggregate gradings used in pervious concrete
are typically either single-sized coarse aggregate
or
grading 3/4 and 3/8 in (between 19 and 9.5 mm).
 A wide aggregate grading is to be avoided as
that will reduce the void content of the pervious
concrete.

12. Contd.
2. Compressive strength
 Falls in the range of 3.5 MPa to 28 Mpa .
Typical values are about 17 Mpa.
3. Flexural strength
 Ranges between about 1 and 3.8 Mpa.
 Influenced by degree of compaction, porosity,
and the aggregate-to-cement (A/C) ratio.

13. Contd
4. Density
 Depends on
-The properties and proportions of the
materials used
-Compaction procedures used in the
placement
 In-place densities in the order of 1600 to 2000
kg/m3
(falls in upper range of lightweight concretes)

14. Contd.
5. Durability: freeze-thaw resistance
 It depend on the saturation level of the voids in
the concrete.
 at the time of freezing Voids are saturated,
complete freezing can cause severe damage.
6. Abrasion resistance
 Open and rough structure- abrasion and raveling
of aggregate on the surface can be a problem
 Hence Highways are generally not suitable for
pervious concretes

15. Design considerations of pervious
cement concrete pavement
Two primary considerations enter into the
determination of the thickness of pervious
concrete pavements.
1) hydrologic design to meet environmental
requirements.
2) structural design to withstand the
anticipated traffic loading applications.

16. Construction
Sub grade –can be native material or imported
fill and properly compacted to achieve Density
90-95%.
surface -Uniform and stable
Sub base – clean gravel or crushed stone.
Sub grade and sub-base - moistened before
placement of pervious concrete layer.
Final layer –compacted by manually operated
roller

17. Mixing and transportation
 Conventional concrete mixing equipment is
used - mixing times may be extended.
 Cement may be replaced by about 10-30%
of fly ash, 20-50% of blast furnace slag and
5% of silica fume.
 Discharged completely within one hour after
initial mixing.
 Retarding admixtures - increase the
discharge time

18. Placement
 Placement - continuous, spreading – rapid.
 Strike off about 15 to 20 mm above the forms.
 Commonly used- mechanical vibrating screed,
manual screeds.
Vibrating ScreedManual Screed

19. Consolidation
 Consolidation-by
rolling over the
concrete with a steel
roller
 Because of rapid
hardening and high
evaporation rates,
delays in
consolidation can
cause problems
Steel Roller

20. Curing
 As pervious concrete
pavements do not bleed,
they have a high tendency
for plastic shrinkage
cracking.
 Recommended curing
procedure -fog misting
followed by plastic
sheeting for 7 days.

21. Maintenance
 Consists of prevention of
clogging and surface
raveling.
 Cleaning by
 Power blowing
 Pressure washing
 Broom sweeping
Raveling
Broom sweeping

22. Environmental benefits
 Reduces storm water runoff.
 Replenishes water tables and aquifers.
 Eliminates - detention ponds - other costly
storm water management practices.
 Allows for more efficient land development.
 Prevents warm and polluted water from
entering streams.

23. Safety benefits
 Reduces storm water runoff.
 Replenishes water tables and aquifers.
 Eliminates - detention ponds - other costly
storm water management practices.
 Allows for more efficient land development.
 Prevents warm and polluted water from
entering streams.

24. Pervious concrete projects
Parking for prime outlets mallin
Williamsburg, Virginia (7.6acres)
Walkway in Beijing, Chinabuilt
for 2008 Olympics

25. Thank you