Types of Bitumen and Their Test Methods Your Name Your Teacher Your Grade

Agenda 1. Types of Bituminous Binders 2. Specifications and Test Methods 3. Testing of Bitumen 4. Relationship between Properties

Types of Bituminous Binders

Types of Binders Tar Natural Asphalt Bitumen

Tar Obtained by destructive distillation of coal or wood. Coke Oven Tar Produced at temperatures above 1200OC during manufacturing of coke. High aromatic content. Pitch content - 50 %. Low Aromatic Tar Produced at temperatures 600OC to 700OC. Less viscous. Paraffinic in nature. Pitch content - 35 %.

Natural Asphalt Naturally occurring Bituminous binder Biggest deposits in Trinidad 100 Acres, 90 meter deep 10 to 15 Million MT Pen - 5 max Asphalt found in France, Italy & Switzerland - Rock Asphalt

Bitumen Cutback Bitumen Emulsions Modified Bitumen Conventional Bitumen Paving Grade Bitumen Industrial Grade Bitumen Cutback Bitumen Emulsions Modified Bitumen Modified Bitumen Emulsions

Specifications and Test Methods Tell which continent your country is located on and which countries are its neighbors. Insert a map of your country.

What is expected from Bitumen? Ensure road behaves in a predictable way Bitumen performs the desired function on the road Does not fail under predictable loads Resists deterioration of road with time Is able to withstand expected climatic conditions Mix easily and form strong bond with a wide variety of aggregates Is safe to handle Modified Bitumen and Bitumen Emulsions should be a stable mixture in storage and handling Insert a picture of one of the geographic features of your country.

What properties need to be tested? Hardness – Penetration Withstand high temperatures – Softening Point Withstand repetitive loading/unloading – Ductility Withstand low temperatures – Fraass breaking point Ease of mixing with aggregate – Viscosity at 135OC Safety in handling - Flash point Purity – Solubility in Trichloroethylene Weight to volume conversion – Specific gravity Deterioration of properties w.r.t. time and temperature – Thin Film Oven Test

Testing of Bitumen Tell which continent your country is located on and which countries are its neighbors. Insert a map of your country.

Penetration Travel in dmm of a specified needle under 100 g wt. for 5 secs into Bitumen at 25OC

Penetration – Test Method Pour the sample into the testing container at not more than 140OC. Stir it thoroughly until it is homogenous and free from air bubbles and water. Pour the sample into the container to a depth of atleast 10 mm in excess of the expected penetration. Allow the sample to cool in atmosphere upto a temperature of 15 to 30OC for 1 to 1 ½ hour. Then place the sample container into the transfer dish and keep it in water bath at 25.0+0.1OC for 1 to 1 ½ hour. Fill the transfer dish with water from the water bath to a depth sufficient to cover the container completely. Place the sample in the penetrometer. Adjust the needle to make contact with the surface of the sample. This can be done by placing the needle point in contact with its image reflected by the surface of the material from a source of light. The atleast 3 readings at points on the surface of the sample atleast 10 mm apart and 10 mm from the side of the dish.

Penetration Test - Accuracy Repeatability Reproducibility Above 50 3% of their average 8% of their average Below 50 1 unit 4 units Penetration Maximum Difference 50 and above 2 unit below 50

Softening Point 3.5 g steel ball placed on Bitumen sample in Brass ring Bath temp. raised at 5OC per minute

Ductility Indicates the extent to which a sample can be stretched before breaking. Length in cm. at breaking point is ductility

Types of Viscosity Tubes Absolute viscosity U-shaped tube with timing marks & filled with asphalt Placed in 60OC bath, Vacuum used to pull asphalt through tube Time to pass marks Visc. in Pa s (Poise) Two viscosity measurements are used in this specification: Absolute viscosity (60 oC) and kinematic viscosity (135 oC). Both use the principle of the rate of flow through a known area to measure viscosity. Because asphalt is still very thick (stiff) at 60 oC, a vacuum is needed to move the asphalt through the tube in a reasonable time. At 135 oC, gravity and a falling head pressure is sufficient to get the asphalt to flow. Asphalt Institute Tube

Flash Point Used to measure temperature to which a sample bitumen may be safely heated The flash point is the temperature reached when the vapour causes an instantaneous flash

Solubility (Purity) A sample of asphalt is dissolved in a solvent then filtered through a Gooch crucible mounted in the top of a vacuum flask. The amount of insoluble material retained on the filter represents the impurities in the asphalt cement.

Thin Film Oven Test Pan Thermometer Rotating Shelf Thin film oven aging is a laboratory procedure for simulating the change in asphalt cement properties which occur during tank storage, mixing and construction processes. This test can also be used to measure the loss of volatiles in the asphalt cement by determining the percent difference in the mass before and after aging. A 50 g sample of asphalt is poured into each of three flat-bottomed pans. This results in a layer of asphalt of about 3.2 mm deep. Three pans are placed on a rotating shelf in a 163 oC oven for 5 hours. The aged samples are then combined into one container, mixed, and used to determine the aged asphalt cement properties. Rotating Shelf

Aging of Bitumen

Other Tests Fraass Breaking Point Specific Gravity Wax content Penetration Ratio/ Index Penetration after TFOT Softening Point after TFOT Viscosity after TFOT

Relationship Between Properties

Interdependencies Penetration at Softening Point – 800 Penetration at Fraass Breaking Pt – 1.25 Interdependencies Viscosity at Softening Point 1200 Pa s (12000 poise)

Relationship Between Properties Penetration at Softening Point – 800 Penetration at Fraass Breaking Point – 1.25 Viscosity at Softening Point - 1200 Pa s (12000 poise)

Interdependencies

Bitumen Test Data Chart

Tests on Emulsions & Modified Bitumens Stability test

Types of Classifications Penetration grade Viscosity grade Viscosity of TFOT residue Performance Grade Hybrid grade Insert a picture of one of the geographic features of your country.

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