1. CONCRETE APPLICATIONS I
CIMT 210
Pervious Concrete:
What is Pervious?
Definition
History
Applications
2. Stormwater Management
Benefits
Recommended Specifications
Hydrologic Analysis
3. Mix Design

2. 1. What is Pervious? DEFINITION
(SEE VIDEO ON PERVIOUS CONCRETE)
It allows rainfall to be captured and to
percolate into the ground.
It reduces stormwater runoff
It recharges groundwater
It supports sustainable construction

3. 1. What is Pervious? B. HISTORY Its not a new technology
(first used in 1852)
2. Federal Clean Water legislation (promotes it.)

4. 1. What is Pervious? C. APPLICATION
1. Its high porosity provides is thermally
insulating (i.e in walls of buildings)
2. It has good acoustical properties
(for sound barrier walls).

5. 1. What is Pervious? C. APPLICATION
Table . Applications for Pervious Concrete
Low-volume pavements
Residential roads, alleys, and driveways
Sidewalks and pathways
Parking areas
Low water crossings
Tennis courts
Subbase for conventional concrete pavements
Patios
Artificial reefs
Slope stabilization
Well linings
Tree grates in sidewalks
Foundations / floors for greenhouses, fish hatcheries,
aquatic amusement centers, and zoos
Hydraulic structures
Swimming pool decks
Pavement edge drains
Groins and seawalls
Noise barriers
Walls (including load-bearing)

6. 2. STORMWATER MANAGEMENT
A. BENEFITS
Its subbase may provide enough water
storage capacity to eliminate the need for
retention ponds, swales, and other
precipitation runoff containment strategies.
2. Its drainage media for hydraulic structures,
parking lots, tennis courts, and greenhouses.
3. It helps owners comply with EPA stormwater
regulations

7. 2. STORMWATER MANAGEMENT
B. Recommended Specifications
 1. Recommended Concrete working time is
usually, one hour between mixing and placing.
2.Using retarders and hydration stabilizers
can extend the working time by as much
as 1.5 hours
  (Density and Porosity)
.A pavement 5 inches (125 mm) thick with
20% voids will be able to store 1 inch (25 mm)
of a sustained rainstorm in its voids.
It covers the majority of rainfall events in the U.S.
6-inch thick subbase of open-graded gravel
increases it to as much as 3” of precipitation
                                                                  

8. 2. STORMWATER MANAGEMENT
B. Recommended Specifications
  (Permeability)
 Typical flow rates through pervious concrete
are 3 to 8 gal/ft²/min, rates of up to 17 gal/ft²/min
(Compressive Strength)
 Compressive strengths ( 500 to 4000 psi)
Typical values are about 2500 psi
Drilled cores best measures in-place strengths
Compaction differences make cast cylinders less
representative of field concrete.
(Flexural Strength)
 Flexural strength (150 psi to 550 psi ).
Flexural strength is affected by compaction,
porosity, and the aggregate-to-cement (A/C) ratio.
Pervious concrete does not require the measurement
of flexural strength for design.

9. 2. STORMWATER MANAGEMENT
B. Recommended Specifications
Freeze –Thaw (continued)
Research indicates that entrained air in the paste dramatically improves freeze-thaw protection
Sulfate Resistance
Aggressive chemicals in soils or water, such as acids and sulfates, are a concern to conventional concrete and pervious concrete
Abrasion Resistance
 Because of the rougher surface texture and open structure of pervious concrete, abrasion and raveling of aggregate particles can be a problem, particularly where snowplows are used to clear pavements.
Highways are generally not suitable for pervious concretes. However, anecdotal evidence indicates that pervious concrete pavements allow snow to melt faster, requiring less plowing.

10. 3. MIX DESIGN A. STRUCTURAL DESIGN Cementitious materials
Portland Cements (ASTM C 150, C 1157)
Blended cements (ASTM C 595, C 1157)
Fly Ash, pozzolans (ASTM C 618)
Ground-granulated blast furnace slag
(ASTM C 989)
 Supplementary cementitious materials (SCMs)
Fly ash, pozzolans, and Slag
These influence concrete performance, setting time, rate of strength development, porosity, permeability, etc.
Silica fume, Fly ash, and Blast furnace slag all increase durability by decreasing permeability and cracking

11. 3. MIX DESIGN A. STRUCTURAL DESIGN
Silica fume is a byproduct of silicone production.
It consists of superfine spherical particles
Used frequently for high-rise buildings
It produces concrete that exceeds 20,000 psi
Silica fume can replace 5-12% cement
Fly ash is the waste byproduct of burning coal in electrical power plants;it used to be landfilled
This material can be used to replace 5-65% of the Portland cement
Blast furnace slag is the waste byproduct of steel manufacturing. It imparts added strength and durability to concrete, and can replace 20-70%
of the cement in the mix.