pourse asplalt hfgu fhd dnndldu for u.pptx

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1. POROUS ASPHALT PAVEMENT prepared by, Zaid Aqeel Abbas 1

2. INTRODUCTION What are porous pavements? “These are the pavements that allow the passage of storm water through surface course layer.” They all have a similar structure consisting underlying reservoir layer but surface course layer (i.e. concrete, asphalt) is depend on purpose . 2

3. 3 Rainfall and Run-off Rainfall Ordinary pavements surface deflects rainwater surface absorbs rainwater What they actually does ?

4. POROUS ASPHALT Lower concentration of fines Voids more than 20% Polymers and/or fibers can be used Mixed at a standard asphalt plant “recharge bed” built of stones 4

5. 5 SECTION OF POROUS ASPHALT PAVEMENT

6. Design of Porous Asphalt Pavement Site Considerations Soil types • Infiltration rates of 0.1 to 10 inches/ hr (tested every 1000m2) Depth of bedrock or impermeable layer (i.e. clay soil) • More than 2 ft deep from the bottom of the reservoir Depth of groundwater • More than 10 ft deep from the bottom of the reservoir Pavement slope • Less than 5% 6

7. DESIGN CRITERIA 4” OPEN GRADED FRICTION COURSE (POROUS PAVEMENT) 4” OF 3/4” WASHED CRUSHED STONE 12”-18” OF 1.5”- 2.5” WASHED CRUSHED STONE UNCOMPACTED SUBGRADE Slope Limit surface slope to 5%. Avoid compacting soils during construction. Avoid excessive earthwork. 7 GEOTEXTILE LAYER

8. Porous Asphalt Pavement Materials 8

9. Chocker Layer – Usually Asphalt Treated Permeable Base (ATPB) • 3/4” open-graded aggregate following Caltrans standard specification • 2.5% Asphalt content (DWA) Aggregate reservoir – 1.5 to 3-inch maximum aggregate size – Single size graded crushed aggregate 9

10. CONSTRUCTION OF PAVEMENT /PARKING LOT EXCAVATED WITHOUT HEAVY EQUIPMENT COMPACTING THE BED BOTTOM. NON-WOVEN GEOTEXTILE IS LAID 10

11. CLEAN (WASHED) UNIFORMLY GRADED AGGREGATE IS PLACED IN THE BED AS THE STORAGE MEDIA. THE ASPHALT IS LAID DOWN JUST LIKE STANDARD ASPHALT AND COMPACTED. 11

12. This road is made of porous asphalt . 12

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14. COMPARISON 14 Low visibility Water splash And spray Traffic noise High visibility Secured skid resistance Quiet Dense Graded Asphalt Pavement Porous Asphalt Pavement

15. COST & MAINTENANCE Total project cost is comparable with ordinary asphalt pavement Material cost is 20-25% more than ordinary asphalt Vacuum sweep twice per year Repairs can be made with standard asphalt not to exceed 10% of surface area 15

16. ADVANTAGES Flood control (Reduces the stormwater runoff) Recharges groundwater to underlying aquifers Extended pavement life due to well drained base Reduced spray from traveling vehicles, reduced roadway noise Allows for reduction of storm water infrastructure 16

17. CONCLUSION Most effective and affordable techniques for addressing storm water management Recharging and replenishing ground water Longer life than ordinary pavements High pollutant removal efficiency by reducing runoff Improving the quality of water Maintaining a cooler pavement 17

18. REFERENCES Akihiro Moriyoshi , Toshiro Jin , Takaaki Nkai and Hiroshi Ishikawa (2013), Construction and Building Materials , Evaluation methods for porous asphalt pavement in service for fourteen years Vol.42 ,pages 190-195. Robert M Roseen , Thomas P Ballestro,James J Houle,Joshua F Briggs and Kristopher M Houle (2012),Journal of environmental vol.138 engineering,water quality and hydrologic performance of a porous apalt pavement as a storm water treatment strategy in a cold climate Mohd Rosli Mohd Hasan,Jia Yih Eng,Moer Othman Hamzah and J.L.m Voskuilen (2013),Construction and Building Materials, The effects of breakpoint location and normal maximum aggregate size on porous asphalt properties vol 44,pages 360-367 Glanluca Dell Acgua ,Moro kura , Raffaelo Mauro and Francesca Russo (2012), procedia -Social and Behaviour Sciences , Freeway crashes in wet weather ;the comparative influence of porous and conventional asphalt surfacing Vol 54,pages 618-627 18

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