Permeable Interlocking Concrete Pavement (PICP) A Low Impact Development Tool Training for Schools and Universities

Transcription

1 Permeable Interlocking Concrete Pavement (PICP) A Low Impact Development Tool Training for Schools and Universities Presented by: Interlocking Concrete Pavement Institute The Low Impact Development Center, Inc. North Carolina State University Permeable Interlocking Concrete Pavement A Low Impact Development Tool 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

2 Learning objectives: - Identify PICP Components - Understand integrated environmental benefits of PICP - - Understand contribution of LEED points from PICP - Understand basic design & maintenance requirements of PICPs Content What is PICP? PICP Costs PICP Benefits Low Impact Development (LID) Designing PICP Systems Construction Maintenance Teaching and Research Opportunities PICP Resources 2

3 What is PICP? 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? Concrete Pavers Permeable Joint Material Open-graded Bedding Course Open-graded Base Reservoir Open-graded Subbase Reservoir System Components Underdrain (As required) Optional Geotextile Under the Subbase Uncompacted Subgrade Soil 3

4 What is PICP? Paver Types: Interlocking Shapes/Patterns Why use 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 4

5 PICP Hydrology Example PICP System Cost 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 5

6 PICP Benefits Local Stormwater Regulations Stormwater and Campuses Sustainable Practices & LEED Inspection Training Available Infrastructure Cost Savings Durable ADA Compliant Surface Research PICP Benefits Local Stormwater Regulations Stormwater and Campuses Sustainable Practices & LEED Inspection Training Available Infrastructure Cost Savings Durable ADA Compliant Surface Research 6

7 Sustainability Tool Manage campus stormwater sustainably Cleans and infiltrates stormwater at the source Teaching Tool PICP Benefits Stormwater and Campuses Opportunity for faculty research Opportunity to train students to use this technology PICP Benefits Local Stormwater Regulations Stormwater and Campuses Sustainable Practices & LEED Inspection Training Available Infrastructure Cost Savings Durable ADA Compliant Surface Research 7

8 PICP Benefits Infrastructure Cost Savings LEED Gold Project Peak flow & pollution reduction, University of Victoria, BC Engineering & Computer Sciences Building PICP Benefits Local Stormwater Regulations Stormwater and Campuses Sustainable Practices & LEED Inspection Training Available Infrastructure Cost Savings Durable ADA Compliant Surface Research 8

9 Water Quality and Quantity Issues Rapidly developing areas hydrology is being radically changed 25% of developed areas are impervious PICP Benefits Stormwater Regulations Campus programs provide the training for the problem solvers of the future: Stormwater is key issue Don River (Toronto) at Bloor Street May 12, 2000 PICP Benefits Stormwater 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 9

10 PICP Benefits Local Stormwater Regulations Stormwater and Campuses Sustainable Practices & LEED Inspection Training Available Infrastructure Cost Savings Durable ADA Compliant Surface Research PICP Benefits Inspection Training Available 10

11 PICP Benefits Local Stormwater Regulations Stormwater and Campuses Sustainable Practices & LEED Inspection Training Available Infrastructure Cost Savings Durable ADA Compliant Surface Research PICP Benefits 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 11

12 PICP Benefits Research Research Examples at Universities: Data analysis, pavement performance comparisons Research & Site Design TRCA Bill Hunt, Kinston, NC Technical Reports Modeling Design TRCA Student labs PICP Benefits 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 12

13 PICP Benefits Research Sustainable Design Research Topics for many disciplines Planning, Landscape Architecture, Biological Engineering, Horticulture, Environmental Engineering, Civil Engineering, Urban Foresters, Ecologists, Architecture.. HUB LINK Campus Green Infrastructure is enhanced by LID tools such as PICP PICP Benefits Research Research Topic: Structural Soil Supports PICP and Tree Growth Collaboration of soil scientists, engineers, landscape architects, urban foresters and/or urban designers Pier A Park Hoboken, NJ, 1998 Image courtesy of Bruce K. Ferguson 13

14 PICP Benefits Local Stormwater Regulations Stormwater and Campuses Sustainable Practices & LEED Inspection Training Available Infrastructure Cost Savings Durable ADA Compliant Surface Research PICP Benefits Sustainable Practices & LEED 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. Dominican University River Forest, IL 165,000 ft² PICP 14

15 PICP Benefits Sustainable Practices & LEED PICP contributes to LEED Credits 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 Benefits Sustainable Practices & LEED Decrease Pollution Through Sustainable Sites (SS) LEED Credit Points 6.1 Reduction of stormwater rate and quantity Treatment of stormwater runoff Increase albedo (reflection of solar radiation) (non-roof surfaces) Increase albedo (segmental paver on roof surface ) 1 15

16 PICP Benefits Sustainable Practices & LEED Conservation of Materials and Resources (MR) Credits - 1 LEED point each: 3.1 5% reused content (i.e. crushed concrete) % reused content 4.1 5% recycled waste content (i.e. flyash) % recycled waste content % manufactured regionally (<500 mi.) % materials extracted regionally (<500 mi.) ICPI Tech Spec 16 PICP Benefits Local Stormwater Regulations Stormwater and Campuses Sustainable Practices & LEED Inspection Training Available Infrastructure Cost Savings Durable ADA Compliant Surface Research 16

17 PICP Benefits ADA Compliant PICP handicapped parking over stormwater detention system Burnaby, BC LID & Stormwater Management Low Impact Development (LID) Principles Work with the landscape Focus on prevention Micromanage stormwater Keep it simple Multi-functional landscapes Maintain and sustain LID tools such as PICP 17

18 LID & Stormwater Management LID: An Innovative Approach Minimize the hydrologic impacts of development LID & Stormwater Management LID 18

19 LID & Stormwater Management LID & Stormwater Management Treatment Train Site Design 1. Source controls = Infiltrate 2. Conveyance controls = Filter & detain 3. End of Pipe Controls = Retain in ponds, streams or storm sewer 19

20 Designing PICP Systems Structural Design Follows standard flexible pavement design procedures Consider: Total Traffic Environment Soil Strength Design Life Adjust layer depths to meet structural requirements Designing PICP Systems Surface Infiltration Design Surface infiltration rate determined by: Joint Material Infiltration Properties In-service sediment deposition rates & vacuum maintenance 20

21 Designing PICP Systems Exfiltration Design 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 Systems Clay In-Situ Soils 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 required at the bottom for expansive clays 21

22 Designing PICP Systems Water Table Concerns Full or Partial Exfiltration No exfiltration 2 ft. 1 ft. Impermeable liner Designing PICP Systems PICP Computerized Design Permeable Design Pro Software integrates: Hydrologic Design Structural Design Contact ICPI to obtain software 22

23 Designing PICP Systems 11 Design Steps: Steps 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 Systems 11 Design Steps: Steps 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 noninfiltrated water 7 Design overflow for rainfalls exceeding the design storm 23

24 Designing PICP Systems 11 Design Steps: Steps 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 Designing PICP Systems Step 8 Check the structural base thickness From Figure 18 in PICP Manual 24

25 Designing PICP Systems Design Details Edge restraint options Pedestrian concrete, plastic for pavers Vehicular concrete curb to other pavements and at pavement edges Construction Subgrade & Base Preparation 25

26 Construction Paver Installation Construction Paver Installation Modular system Uses existing installation machinery Construction in freezing temperatures 26

27 Construction Joint Aggregate Installation Annually: inspection of observation well after major storm, vacuum and sweep surface improves infiltration Maintenance checklist Model maintenance agreement Monitor adjacent uses Maintenance Freeze-thaw/snow removal: minimal issue Won t treat de-icing salts 27

28 PICP Resources Documents on ICPI.org Design Manual Project Profiles Pavement Comparison Fact Sheets Design manual Design software Presentations PICP Resources

29 Questions? 29