Porous Asphalt Pavement

Porous Asphalt Pavement - CGN 6506 Bituminous Materials and...

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Unformatted text preview: CGN 6506 Bituminous Materials and Mixtures Fall 2010, University of Florida Porous Asphalt Pavement Term Paper Presentation December 3, 2010 Mitsuhiro NARISAWA What is Porous Asphalt Pavement? High High Air Voids(20%) Functional Functional Pavement Drainage Drainage Skid Skid Resistance Noise Noise Reduction Common Common Technology in Europe and Asia 1950s 1950s - U.S. Runoff Runoff Control – Parking Lots 1980s 1980s - Europe & Asia Environment & Safety – Highways Outline Porous Asphalt Pavement Functions - Safety, Noise Reduction Properties - Aggregate, Binder & Mix Others Maintenance Recycling Water Retentive Asphalt Can be used in the U.S ? Function of Porous Asphalt Pavement Drainage Drainage Rain Surface Course Pervious Layer Porous Asphalt Mix Water Base Course Impervious Layer Dense Graded As or SMA Function of Porous Asphalt Pavement Safety Safety Effect Drainage Drainage Skid Skid Resistance Accident Rate (# of Accidents/100millions vehicles*km) Function of Porous Asphalt Pavement Reduction Reduction of Tire Noise Low Compression & Expansion Compression Release air Normal Pavement Absorb Absorb Noise Porous Pavement Function of Porous Asphalt Pavement Noise Level (dB) Noise Noise Reduction Effect of 3dB Velocity (km/h) Same Same as -Decrease 50% of Traffic Volume -Slowdown by 20% of Traffic Velocity Property of Porous Asphalt Mix General General Aspects % Passing % Passing Aggregate of Porous Asphalt Pavement 2.36mm Sieve Sizes (mm) Fine Fine Aggregate < 20% LA LA Abrasion Loss < 30 %, Density>2.45 Absorption Absorption < 3%, Flat& Elongated Particle<10% Max Max size 13mm(Snowy), 20mm(Normal) Binder of Porous Asphalt Pavement High Air voids require binder to have High Durability & Adhesion. High-viscosity modified (High Elasticity) asphalt Test Items Standard Properties 10mm) Penetration (25 °C, 1/10mm) Min 40 Softening Point (°C) Min 80 Ductility (15 ° C, cm) Min 50 Flash Point (° C) Min 260 Loss on TFOT (%) Max 0.6 Residual Penetration Ratio After TFOT (%) Min 65 Toughness (Nm) Min 20 Tenacity (Nm) Min 15 Viscosity at 60 °C (Pa・s) Min 20,000(40,000) Binder of Porous Asphalt Pavement Bending Test Load (N) ToughnessToughness-Tenacity Bonding Strength =Breaking Energy of Adhesive Displacement (cm) Binder of Porous Asphalt Pvt High-viscosity modified asphalt Butadiene Styrene block copolymer "SBS" High High Concentration & Dispersion Required Asphalt Mix of Porous Asphalt Pvt Test Items Value % Air Voids 20% (17%:Cold region) Permeable Coefficient (cm/s) Min. 10-2 Marshall Stability Min3.5kN or 5.0kN(Highway) Dynamic Stability Min 3000 pass/mm Cantabro Loss 20% at -20C, Cold area 20% at 20C, Normal area Rutting Resistance (Wheel Trucking Test) Fretting Resistance -Abrasion Loss of Compacted Mix -LA Abrasion Machine without Steel Ball Maintenance of Porous Asphalt Rutting Rutting & Cracking: Better than Normal Pvt Aggregate Aggregate Fretting & Clogging are problem Situ Situ Permeability (ml/15s) Top Coat & Cleaning is necessary Number of Oversized Vehicle Recycle of Porous Asphalt Pavement High High quality Aggregates, but Modified Binder A) B) 30% to 50% of RAP can be used to produce recycled Porous or Dense asphalt mix 100% Aggregate Recycle Technically possible High Cost Steel Balls used in recycle Produced Primary Aggregate Water-retentive Pavement B) Water moisturizing materials in porous asphalt pavement Decrease surface temperature by 10 to 20 °C Mitigate urban heat island Increase Rutting Resistance Temperature(°C) C A) Cross section Date in 2009 Can be used in U.S? Comparison Comparison of Axle Load Limits Axle Limits in the U.S. Single Axle 20,000 lb Tandem Axle Limits in Japan 34,000 lb 10t (≈22,000lb) Gross Vehicle Weight 80,000 lb 25t (≈ 55,000lb) Axle Axle Loads used in Design U.S. Standard Axle 18-kip (80kN) <106 ESALs Japan 106 to >107 Level 1 107 Level 2 49kN(12-kip) ≈ 0.2×106 (18-Kip) 1×106(N5 traffic) ≈ 1.3×106 (18-Kip) 7×106(N6 traffic) ≈ 6.6×106 (18-Kip) 3.5×107(N7 traffic) (18(18 Level 3 EALF=Wt18/Wt12=0.189 Comparison of Pavements U.S. U.S. Japan Long Long life Pavement Superpave Design Concrete Pavement U.S. Heavy Sparcity 9×106km2 0.7km/km2 Functional Pavement Porous Asphalt Pvt Water Retentive Pvt Limits in the U.S. Traffic Load Land Use Area of Roads* Japan Medium Dense 3×105km2 3.2km/km2 Road Density* *IRF World Road Statistics 2006 ...
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