interlocking concrete pavement institute the low … · interlocking concrete pavement institute...

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Presented by:

Interlocking Concrete Pavement Institute

The Low Impact Development Center, Inc.

North Carolina State University

Permeable Interlocking Concrete

Pavement (PICP)

A Low Impact Development Tool

Training for Schools and Universities

This program is registered with the AIA/CES and ASLA CPE for

continuing education professional education. As such, it

does not include content that may be deemed or construed

to be an approval or endorsement by the AIA or ASLA of

Any material of construction or any method or manner of

handling, using, distributing, or dealing in any material or product.

Questions related to specific materials, methods, and services will

be addressed at the conclusion of this presentation.

Dec. 19, 2008 Program 000011

Permeable Interlocking

Concrete Pavement

A Low Impact Development Tool

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Learning objectives:

• - Identify PICP Components

• - Understand integrated

environmental benefits of

PICP

- - Understand contribution of

LEED points from PICP

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• - Understand basic design &

maintenance requirements

of PICPs

• What is PICP?

• PICP Costs

• PICP Benefits

• Low Impact Development (LID)

• Designing PICP Systems

• Construction

• Maintenance

• Teaching and Research Opportunities

• PICP Resources

Content

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A solid interlocking paver system – water drains

through permeable joint material

Strong & durable paving system well-suited for low

traffic areas: parking lots, parking bays & low-speed

streets

What is PICP?

What is PICP? Concrete Pavers

Open-graded

Subbase

Reservoir

Uncompacted

Subgrade Soil

Open-graded

Base Reservoir

Underdrain

(As required)

Optional Geotextile

Under the Subbase

Permeable Joint Material

Open-graded

Bedding Course

System

Components

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Paver Types: Interlocking Shapes/Patterns

What is PICP?

• Recent regulations encourage managing runoff at the source

• PICP reduces or eliminates need for detention ponds & storm sewer pipes

• PICP reduces runoff, pollutants; recharges groundwater & helps reduce downstream erosion & flooding

• Cost-effective site use: pedestrian & vehicular pavements combined with detention areas

Why use PICP?

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PICP Hydrology Example

Assumptions:

• Paver Thickness: 3 in. (8 cm)

• Bedding Layer: 2 in. (5 cm)

• Base Layer: 8 in. (20 cm)

• Total Area: 15,000-20,000 ft² (1,500 to 2,500 m²)

• Prevailing Wages

• Does NOT include design, concrete curbs, excavation, and pipe costs

• $ 7-12/sf

PICP System Cost Example

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Inspection Training

Available

Durable ADA

Compliant Surface

Local Stormwater

Regulations

Research

Infrastructure

Cost Savings

Stormwater and

CampusesSustainable

Practices & LEED

PICP Benefits

Inspection Training

Available

Durable ADA

Compliant Surface

Local Stormwater

Regulations

Research

Infrastructure

Cost Savings

Stormwater and

CampusesSustainable

Practices & LEED

PICP Benefits

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• Sustainability Tool

– Manage campus stormwater sustainably

– Cleans and infiltrates stormwater at the

source

• Teaching Tool

– Opportunity for faculty research

– Opportunity to train students to use this

technology

PICP BenefitsStormwater and Campuses

Inspection Training

Available

Durable ADA

Compliant Surface

Local Stormwater

Regulations

Research

Infrastructure

Cost Savings

Sustainable

Practices & LEED

PICP Benefits

Stormwater and

Campuses

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LEED® Gold Project

Peak flow & pollution reduction,

University of Victoria, BC

Engineering & Computer Sciences

Building

PICP BenefitsInfrastructure Cost Savings

Inspection Training

Available

Durable ADA

Compliant Surface

Local Stormwater

Regulations

Research

Infrastructure

Cost Savings

Sustainable

Practices & LEED

PICP Benefits

Stormwater and

Campuses

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Water Quality and Quantity Issues

Don River (Toronto) at Bloor Street – May 12, 2000

• Rapidly developing areas hydrology is being radically changed

• 25% of developed areas are impervious

• Campus programs provide the training for the problem solvers of the future: Stormwater is key issue

PICP BenefitsStormwater Regulations

PICP BenefitsStormwater Regulations

Water Quantity

• Reduces volumes & peak flows via infiltration

• Imitates predevelopment conditions: no runoff from common storms

• Reduces or eliminates retention/detention facilities & conserves

land

• Reduces stormwater utility fees

Water Quality

• Reduced downstream erosion, preserves drainage system

• Filters & reduces nutrients, metals

• Recharges groundwater

• Helps maintain dry-weather stream flows

• Filters oil drippings

• Reduces runoff temperatures

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Inspection Training

Available

Durable ADA

Compliant Surface

Local Stormwater

Regulations

Research

Infrastructure

Cost Savings

Sustainable

Practices & LEED

PICP Benefits

Stormwater and

Campuses

PICP BenefitsInspection Training Available

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Inspection Training

Available

Durable ADA

Compliant Surface

Local Stormwater

Regulations

Research

Infrastructure

Cost Savings

Sustainable

Practices & LEED

PICP Benefits

Stormwater and

Campuses

Example Teaching Opportunities

• Campus real life laboratory in paved surface areas

• Lab opportunities for analysis of water samples

• Train students how to design hydrologically functional pavements

• Integrated visual and functional design

• Problem-solving for multiple objectives

PICP Benefits

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Research Examples at Universities: Data analysis, pavement performance comparisons

Research & Site Design

Modeling Design

Technical Reports

©TRCA

Bill Hunt, Kinston, NC

Student labs

PICP BenefitsResearch

©TRCA

Ongoing Research Needs

• Volume reductions

• Water quality improvements

• Reflectivity (albedo) – cool surface quantification

• Winter performance; deicing salt use

• Maintenance protocols

• New applications (e.g. coatings for AQ benefits)

• Comparison studies to other pavements

• Benefits to trees & other vegetation

• Life cycle assessment for impacts & benefits

• Life-cycle cost analyses

PICP Benefits

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Sustainable Design Research Topics for many disciplines

LINKHUB

Planning, Landscape Architecture, Biological Engineering,

Horticulture, Environmental Engineering, Civil Engineering,

Urban Foresters, Ecologists, Architecture…..

Campus Green Infrastructure is enhanced by LID tools such as PICP


Pier A Park

Hoboken, NJ, 1998Image courtesy of Bruce K. Ferguson

Research Topic:

Structural Soil Supports PICP and Tree Growth

Collaboration of soil scientists, engineers, landscape architects,

urban foresters and/or urban designers


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Inspection Training

Available

Durable ADA

Compliant Surface

Local Stormwater

Regulations

Research

Infrastructure

Cost Savings

Sustainable

Practices & LEED

PICP Benefits

Stormwater and

Campuses

Dominican UniversityRiver Forest, IL

165,000 ft² PICP

Sustainable Design & Stormwater Management Research

Elmhurst College, IL

125 space parking lot with

underground cisterns,

detention areas under

pavement linked to

bioretention areas.

Effectiveness monitored by

science faculty, chemistry &

biology students.

LEED® Gold Project

Seneca College

King City, Ontario

Multiple paving

types evaluated.

PICP BenefitsSustainable Practices & LEED

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• Decrease pollution through sustainable sites (SS)

• Increase building water use efficiency (WE)

• Reduce energy and atmospheric pollutants (MR)

• Conserve materials and resources (MR)

• Improve indoor air quality (EQ)

• Offer innovative ideas and designs (ID)

PICP contributes to LEED Credits


LEED®

Credit Points

6.1 Reduction of stormwater rate and quantity 1

6.2 Treatment of stormwater runoff 1

7.1 Increase albedo (reflection of solar radiation)

(non-roof surfaces) 1

7.2 Increase albedo (segmental paver on roof surface ) 1

Decrease Pollution Through Sustainable Sites (SS)


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Credits - 1 LEED® point each:

3.1 5% reused content

(i.e. crushed concrete)

3.2 10% reused content

4.1 5% recycled waste content

(i.e. flyash)

4.2 10% recycled waste content

5.1 20% manufactured

regionally (<500 mi.)

5.2 50% materials extracted

regionally (<500 mi.)

Conservation of Materials and Resources (MR)

ICPI Tech Spec 16


Inspection Training

Available

Durable ADA

Compliant Surface

Local Stormwater

Regulations

Research

Infrastructure

Cost Savings

Sustainable

Practices & LEED

PICP Benefits

Stormwater and

Campuses

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PICP handicapped parking over stormwater detention system

Burnaby, BC

PICP BenefitsADA Compliant

• Work with the landscape

• Focus on prevention

• Micromanage stormwater

• Keep it simple

• Multi-functional landscapes

• Maintain and sustain LID tools such as

PICP

LID & Stormwater ManagementLow Impact Development (LID) Principles

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Minimize the hydrologic impacts of development

LID & Stormwater ManagementLID: An Innovative Approach

LID & Stormwater ManagementLID

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LID & Stormwater Management

1. Source controls = Infiltrate

2. Conveyance controls = Filter & detain

3. End of Pipe Controls = Retain in ponds, streams

or storm sewer

LID & Stormwater ManagementTreatment Train Site Design

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• Follows standard flexible pavement

design procedures

• Consider:

– Total Traffic – Environment

– Soil Strength – Design Life

• Adjust layer depths to meet structural

requirements

Designing PICP SystemsStructural Design

• Surface infiltration rate determined by:

– Joint Material Infiltration Properties

– In-service sediment deposition rates

& vacuum maintenance

Designing PICP SystemsSurface Infiltration Design

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• Exfiltration: water returned to underlying soil

• Use washed aggregate to prevent clogging

• Exfiltration limited by permeability of underlying soil

• When an underdrain is required, leave a gravel storage layer below underdrain to encourage exfiltration

Designing PICP SystemsExfiltration Design

PICP can be used, however:

• Peak flow reduction still likely

• Minimal runoff reduction volume

• Extra gravel required for strength and storage

• Underdrain system required

• Impermeable layer requiredat the bottom forexpansive clays

Designing PICP SystemsClay In-Situ Soils

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2 ft. 1 ft.

Full or Partial Exfiltration No exfiltration

Impermeable liner

Designing PICP SystemsWater Table Concerns

• Permeable Design Pro

• Software integrates:

– Hydrologic Design

– Structural Design

• Contact ICPI

to obtain software

www.icpi.org

Designing PICP SystemsPICP Computerized Design

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1 – Assess soil conditions, design

storm depth; determine exfiltration

option

2 – Compute increased runoff depth from

area contributing to the permeable

pavement (if any)

3 – Compute the depth of the base for

storage

Designing PICP Systems11 Design Steps: Steps 1 – 3

4 – Compute the maximum base depth for

drainage in 24, 36 & 48 hours given

conservative soil infiltration rate

5 – If needed, revise base depth to accommodate

storage and site area limitations

6 – Design perforated pipes at base to drain non-

infiltrated water

7 – Design overflow for rainfalls exceeding the

design storm


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8 – Determine the base thickness for traffic using

“Structural Base Thickness Table” (See next

slide)

9 – Compare to base thickness for traffic to

thickness for water storage:

always use thicker base

10 – Check clearance from bottom of base to

seasonal high water table (> 2 ft)

11 – Check geotextile filter criteria


From Figure 18 in PICP Manual

Designing PICP SystemsStep 8 – Check the structural base thickness

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Edge restraint options

Pedestrian – concrete, plastic for pavers

Vehicular – concrete curb to other pavements and at pavement edges

Designing PICP SystemsDesign Details

ConstructionSubgrade & Base Preparation

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ConstructionPaver Installation

• Modular system

• Uses existing installation machinery

• Construction in freezing temperatures

ConstructionPaver Installation

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ConstructionJoint Aggregate Installation

• Annually: inspection of observation well after

major storm, vacuum and sweep surface –

improves infiltration

• Maintenance checklist

• Model maintenance agreement

• Monitor adjacent uses

• Freeze-thaw/snow

removal: minimal issue

• Won’t treat de-icing salts

Maintenance

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Design Manual

PICP ResourcesDocuments on ICPI.org

Project Profiles Pavement Comparison

• Fact Sheets

• Design

manual

• Design

software

• Presentations

www.icpi.org

www.ncsu.edu/picp

www.lowimpactdevelopment.org

PICP Resources

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Questions?