THE DESIGN OF POROUS PAVEMENT SHOULDERS AT RICHMOND INTERNATIONAL AIRPORT 33 rd Annual Airports Conference March 3, 2010 – Hershey, PA Presented by: H.

THE DESIGN OF POROUS PAVEMENT SHOULDERS

AT RICHMOND INTERNATIONAL AIRPORT

33rd Annual Airports Conference

March 3, 2010 – Hershey, PA

Presented by: H. D. Campbell, Jr., P.E.

Campbell & Paris Engineers

PROJECT DESCRIPTION

• THE PROJECT Design and construct a 35’ porous pavement shoulders at RIC along

new Taxiways A & E. Design period – 1994. Construction period – 1995 - 1996

• THE PURPOSEThe airport is unable to provide adequate storm water retention areas for the new taxiway paved areas within present property limits. Another method of reducing the storm water time of concentration must be provided.

• THE SOLUTIONProvide 35’ wide porous pavement shoulders along each edge of the new taxiways

DESIGN

• METHODOLOGY, BACKGROUND & SITE CONDITIONS

WADO requests feasibility study for justification approval

Post development runoff must not exceed pre development

Concerns arise over bird strike potential with existing basins

Poor draining soils at the site

• SOIL MOISTURE AND WATER TABLE FACTORS

SC and SM soils throughout site

Natural moisture at 15% and above

CL layer underlying area creates perched water table

Site of War Between the States Battle Field

DESIGN

• STORM WATER QUANTITY AND QUALITYIntercept first 15 minutes of runoff washing over pavementLimit post development flows to pre development valuesMaintain quantity/quality of water in existing basins

• PROVIDE FOD PROTECTION FOR GROUP 5 AIRCRAFT35’ Shoulder Pavement Protection for Outboard Engines

• STRUCTURAL DESIGN OF THE SHOULDER PAVEMENTUse 1990s AC 150/5300 for annual 2 passes of 125K dual gear landing gear configuration (250K MTOW dual gear aircraft)

DESIGN

• STRUCTURAL DESIGN OF POROUS SHOULDER SURFACE No FAA standard in 1990s

Surface Course to be P-402 3/4 to 1 inch in thickness with known performance and availability

Make up difference in surface course deficiency with stabilized base

DESIGN

• STRUCTURAL/FUNCTIONAL DESIGN OF POROUS BASE/SEPARATION LAYERPorous base divided into base placed directly below the P-402 and the separation layer placed on the subgrade and below the base course

Porous base #57 aggregate stabilized with cement at W/C ratio of 0.37 for structural purposes. The separation layer is #68 non stabilized aggregate

Thickness of 17” based on permeability of layers

Minimum permeability set for 3000 foot per day (FPD) based on cement stabilized layer

Time of concentration for 17” layer at 35’ wide was 17 minutes for a 20 year storm

Lateral drains placed at 300’ intervals drain to paved ditch

POROUS SHOULDER CONSTRUCTION

POROUS SHOULDER CONSTRUCTION

POROUS SHOULDER CONSTRUCTION

DESIGN

• FINAL PAVEMENT DESIGN SECTION ¾-1 inch P-402 Porous Friction Course

9 inches AASHTO # 57 Cement Stabilized Aggregate (at at W/C ratio of 0.37)

7 inches AASHTO # 68 Separation Layer

• PERFORMANCE In service since 1996 with no adverse reports

QUESTIONS?

• Thank you for your time