dr. sönke borgwardt dr. soenke borgwardt buero bwb norderstedt fehmarnstrasse 37 d-22846...

Dr. Sönke Borgwardt

Dr. Soenke BorgwardtBuero BWB NorderstedtFehmarnstrasse 37D-22846 NorderstedtTlf. +49 (0)40 522 56 75Fax +49 (0)40 53 53 06 [email protected]

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Water Permeable Pavements

Presentation SEPT-Workshop 2011 in Dresden

Importance and Principles

Infiltration Performance

Selection and Areas of Application

Requirements and Design Considerations

Layout and Detailing

Maintenance and Monitoring

Permeable Concrete Block Paving (pCBP)



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Relieving Sewage Systems w/ Reduced Runoff



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Method: Reducing Runoff w/ Permeable CBP

• Absorption of Precipitation

With Permeable Surface

• Temporary Retention of Infiltrated Rainwater

With Permeable Pavement Structure

• Partial Infiltration of Seepage Water

Through the Formation Level depending on the Permeability of the Soil

• Restricted Recharge of the Remaining Runoff

With Connected Drainage Facilities

• Collecting the Seepage Water

With Impermeable Membranes on the Surface of the Formation Level

• Collecting the Remaining Runoff

For further Use



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Retention

Retention

Infiltration

Infiltration

Restricted Discharge

Principle: Reducing Runoff w/ Permeable CBP



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Reducing Runoff as a Component of SUDS



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Research: Permeability Reduction by Clogging

0

10

20

30

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50

60

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0.02 0.063 0.2 0.63 2 0.6 20

particle size d in mm

scre

en p

assi

ng (

<d

in m

ass-

%)

silt sand gravel

Upper 20 mm

Below 20 mm



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Results: Long-term Performance (Aging)



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Conclusions: Reduced Runoff Coefficient



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• Determination of Possible Areas of application according to Traffic Load and Protection of Soil and Groundwater

• Judging the Soil according to Load Bearing Capacity and Permeability

• Designing the Road Construction according to Load Bearing Capacity and Permeability

• Selecting the Materials according to Load Bearing Capacity and Permeability

• Selecting the Permeable Paving Blocks according to Aesthetics and Infiltration Performance

• Choosing and Designing the Connected Drainage Facility

• Determination of Suitable Methods for Monitoring the Infiltration Performance

• Determination of Suitable Methods to Maintain the Infiltration Performance

Preconditions

General Requirements: No Affection of Soil and Ground Water Permanent Road Operation

(Damage-free Construction) Permanent Infiltration

(Proper Reduction of Runoff) Proper and Regular Drained Surface

(Safe Road)



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Areas of ApplicationTraffic area Use

Roads Residential Roads, Access Roads, Service Roads

Parking Areas Parking Areas occasional in use for Truck and Bus Traffic,Parking Areas constantly in use for Car Traffic and minor Truck/Bus Traffic

Industrial Traffic Areas

Industrial Roads with minor Traffic, Industrial Parking Areas,Container Hard Standings

Special Traffic Areas

Track and Rail Areas of Public Transport,Airbase Aprons and Parking Areas for Planes

Other Traffic Areas

Platforms for Public Transport, Farm and Forestry Roads,Emergency Escape Ramps

Residential/ Private Areas

Cycle Ways and Footpaths, Real Property Entries,Landscape and Garden Areas



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Areas of Application



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Areas of Application



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Determination of Construction and Thickness according to:• Frost Susceptibility of the Soil (→ Permeability)• Local Climate Conditions• Structural Performance of Aggregates and Base Courses• Design Traffic Load

Performance Criteria:Criteria:• Complete and Permanent Infiltration of a Standard Rainfall

Measure

Required Rainfall Measure (i.e. In the UK):• BRE Digest 365 (Soakaway design):

M5-10 = 180 l/(sha) eq. 1,08 mm/min• Required permeability of the soil:

kukf/2 = 3.610-5 m/s

Design Methods



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Criteria:• Sufficient Permeability to Absorb the Standard Rainfall

Measure• Required Permeability according to Aging:

3.610-4 m/s

• According to Percentage of Openings:

[m/s]% in openings of percentage

100kfk u

Mineral Aggregates:Openings/Bedding:

Crushed Gravel 1/3 to 2/5 mmBase course:

Modified Type 3 Material (Fines < 3 M.-%)

Performance Criteria



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Pavement Design with Permeable CBP

Base Course Thickness: Depending on Soil Permeability

Materials: Permeability according to Design-Rainfall

Permeable Paving: Depending on Traffic Load



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Pavement Design with Permeable CBP



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• Suitability tests of the materials

• Suitability tests of the soil

• On-site acceptance tests

Type of Testing:

Lab Tests

Open-End-Test

Infiltration Test

Monitoring



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Monitoring: Testing the Subgrade



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Monitoring: Testing the Base Course



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Monitoring: Testing the Surface



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Monitoring: Testing the Surface



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Control of Pavement Condition and Function

• Assessment of Structural and Drainage Performance

Control of Joints and Joint Filling

• Completely Filled Joints Guarantee Horizontal Load Transmission!

Road Cleaning

• Mechanical Cleaning only 3 Months after Completion!

• Periodical Cleaning Afterwards can not Replace an Additional Drainage!

• In Practice Maintenance is Expensive!

Maintenance



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The Overall Costs of Permeable Road Constructions are related to Conventional Road Constructions:

•Regularly the Same with Good Soil Conditions

•A little Higher with Bad Soil Conditions

Detailed Costs in Comparison to Conventional Road Constructions:

•Permeable Paving Blocks: Higher

•Base Courses: Same with Good Soil Conditions

Higher with Bad Soil Conditions

•Drainage Facilities: Lower

Costs



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Origin and Types of Overstress of the Pavement:

• Premature Exhaustion

• Sudden Local Collapse

• Long-ranging Permanent Deformation

Failures, Defects, Damages



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Failures, Defects and Damages



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Quality Assessment

Purpose: Prevention of Constructional Damages

Method: Quality Improvement w/ Continuous Job-site Monitoring

Goal: • Document the technical and legal precise state of the art.

• Raise the standard of specification balanced for all parties.

• Improve the technical qualification of designers, specifiers, contractors and manufacturers.

• Continuously review the job-site construction work.



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Quality Assessment – Rectification Costs



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Quality Assessment – Methods

Documentation of the whole Sequence of Construction by

• Elaboration of Daily Work Step Checklists

(Contractor with Expert)

• Supervision of Documents by Integrity, Plausibility, Conformity

(Inspector of the Contractor)

• Monitoring of Documents and Work Progress

(External Expert)



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Quality Assessment

Checklists include i.e.:

• Incoming Controls of Building Materials

• Controls of Installation

• Controls of Pavement



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Accompanying Control Tests for Internal Controls, i.e.

• Compaction

• Difference in Elevation

• Difference in Evenness

• Joint Widths

Quality Assessment – Methods

dr. sönke borgwardt dr. soenke borgwardt buero bwb norderstedt fehmarnstrasse 37 d-22846...

Documents

snke borgwardt

norderstedt tlf

runoff w permeable cbp

clogging slide

use slide

remaining runoff

dresden importance

dresden research