Dr. Wa'el M. Albawwab ECGD4228 Transportation Engineering II Summer 2008 Sat. 15:30-18:30 PM K004

Dr. Wa'el M. Albawwab  Pavement Purposes and Significance  Pavement Conditions  Pavement Types  Paving Materials Lecture 4

Dr. Wa'el M. Albawwab  Pavement Materials  Pavement Structural Analysis  Pavement Design  Pavement Maintenance  Pavement Rehabilitation  Pavement Management Systems Pavement Engineering

Dr. Wa'el M. Albawwab  Road pavements are structures designed and built on existing grounds to facilitate smooth, safe, reliable, and convenient traffic flows. General Definition

Dr. Wa'el M. Albawwab  Flexible Pavements  Rigid Pavements  Mixed Pavements Categories of Road Paving

Dr. Wa'el M. Albawwab Category I: Flexible Pavements

Dr. Wa'el M. Albawwab  Hot mix asphalt (HMA) pavements  Considered as flexible structures since the total pavement structure flexes to conform the applied traffic loads Categories of Road Paving Flexible Pavements

Dr. Wa'el M. Albawwab  Traffic Lanes  Auxiliary Lanes  Parking Lots  Shoulders  Ramps Typical Applications of Flexible Pavements

Dr. Wa'el M. Albawwab  Adjusts to limited differential settlements  Easy repair and maintenance  Maintains non-slip properties  More convenient for drivers  Tolerates a wide range of temperatures Advantages of Flexible Pavements

Dr. Wa'el M. Albawwab  Flexibility and cohesion decrease with time  Requires resurfacing sooner than rigid paving  Normally not suitable for dominantly wet areas Disadvantages of Flexible Pavements

Dr. Wa'el M. Albawwab Types of Flexible Pavements Dense Graded

Dr. Wa'el M. Albawwab Types of Flexible Pavements Open Graded

Dr. Wa'el M. Albawwab Types of Flexible Pavements Gap Graded

Dr. Wa'el M. Albawwab Surfaces of Flexible Pavements

Dr. Wa'el M. Albawwab Surfaces of Flexible Pavements

Dr. Wa'el M. Albawwab Surfaces of Flexible Pavements

Dr. Wa'el M. Albawwab Structure of Flexible Pavements

Dr. Wa'el M. Albawwab Load Distribution in Flexible Pavements

Dr. Wa'el M. Albawwab Load Effect in Flexible Pavements

Dr. Wa'el M. Albawwab Configuration of Flexible Pavements Heavy Traffic Volumes

Dr. Wa'el M. Albawwab Configuration of Flexible Pavements Light Traffic Volumes

Dr. Wa'el M. Albawwab  Asphalt (Bitumen) is a waste product from refinery processing of crude oil  Sometimes called the “bottom of the barrel”  Properties depend on:  Composition of crude source  Refinery operations Composition of Flexible Pavements Bituminous Materials

Dr. Wa'el M. Albawwab Configuration of Flexible Pavements Refined Crude Oil

Dr. Wa'el M. Albawwab  Bituminous Binders  Asphalt Cement  Cutback Asphalt  Emulsified Asphalt  Asphalt Concrete (Binder + Aggregate) Composition of Flexible Pavements Bituminous Materials

Dr. Wa'el M. Albawwab  Asphalt cements: Generally refinery produced material - Air blown  Cutbacks: Asphalt cements “cut” with petroleum solvents  Emulsions: Mixture of asphalt cement, water, and emulsifying agents Composition of Flexible Pavements Bituminous Binders

Dr. Wa'el M. Albawwab Composition of Flexible Pavements Chemical Composition of Asphalt Cement ElementPortion Carbon 85 % Hydrogen 10 % Sulfur % Nitrogen % Oxygen % Vanadium < 1400 ppm Nickel < 110 ppm

Dr. Wa'el M. Albawwab  Asphaltenes  Large, discrete solid inclusions (black)  High viscosity component  Resins  Semi-solid or solid at room temperature  Fluid when heated  Brittle when cold  Oils  Colorless liquid  Soluble in most solvents  Allows asphalt to flow Composition of Flexible Pavements Components of Asphalt Cement

Dr. Wa'el M. Albawwab  Rapid cure (RC) (Naphtha or Gasoline)  High volatility of solvent  Tack coats, surface treatments  Medium cure (MC) (Kerosene)  Moderate volatility  Stockpile patching mix  Slow cure (SC) (Low viscosity oil)  Low volatility  Prime coat, dust control Composition of Flexible Pavements Cutbacks

Dr. Wa'el M. Albawwab Composition of Flexible Pavements Emulsified Asphalts

Dr. Wa'el M. Albawwab  Hot mix asphalt concrete (HMAC): Asphalt cement and aggregate heated to 300°F & mixed  Cold mix: Aggregate mixed with liquid asphalt  Surface treatments (or seal coats)  Prime coats and tack coats  Slurry seals  Crack seals Composition of Flexible Pavements Different Usages

Dr. Wa'el M. Albawwab  Consistency, measured by  Kinematic viscosity at 135°C (in mm 2 /sec)  Absolute viscosity at 60°C (in 0.1 Pa.Sec)  Penetration Test at 25°C (in 0.1 mm)  Aging during production of HMAC & service  Rolling Thin-Film-Oven-Test (RTFOT)  Durability, which is the resistance to  Oxidation, volatilization, age-hardening  Stripping of asphalt from aggregate  Lottman Test Composition of Flexible Pavements Testing of Asphalt Properties

Dr. Wa'el M. Albawwab Flexible Pavements Testing of Subgrade Properties  Characterized by strength and/or stiffness  California Bearing Ratio (CBR)  Measures shearing resistance  Typical values: %  Resilient Modulus (M R )  Measures stress-strain relationship  Typical values: 3, ,000 psi (20 – 275 MPa)

Dr. Wa'el M. Albawwab GradeCBR M R (psi) Typical Description Good ≥ 10 20,000 Gravels, crushed stone and sandy soils. GW, GP, GM, SW, SP, SM soils are often in this category. Fair 5 – 9 10,000 Clayey gravel and clayey sand, fine silt soils. GM, GC, SM, SC soils are often in this category. Poor 3 – 5 5,000 Fine silty sands, clays, silts, organic soils. CL, CH, ML, MH, CM, OL, OH soils are often in this category. Testing of Subgrade Properties

Dr. Wa'el M. Albawwab Construction of Flexible Pavements

Dr. Wa'el M. Albawwab Construction of Flexible Pavements

Dr. Wa'el M. Albawwab Construction of Flexible Pavements

Dr. Wa'el M. Albawwab Construction of Flexible Pavements

Dr. Wa'el M. Albawwab Construction of Flexible Pavements

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Condition vs. Time

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Low Severity Fatigue Cracking

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Moderate Severity Fatigue Cracking

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements High Severity Spalled Fatigue Cracking

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Chicken Wire / Alligator Pattern Fatigue Cracking

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Longitudinal Fatigue Cracking

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Transverse Fatigue Cracking

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Blocked Fatigue Cracking

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Edge Fatigue Cracking

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Rutting

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Rutting

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Shoving (Heavy Weight Impact)

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Shoving (Heavy Weight Impact)

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Potholes

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Water Bleeding and Flushing (Pumping)

Dr. Wa'el M. Albawwab Distresses in Flexible Pavements Frost Thawing

Dr. Wa'el M. Albawwab Rehabilitation of Flexible Pavements Resurfacing