Flakiness and Elongation Test

Objective : To determine the flakiness index of aggregates

Apparatus A metal gauge plate

Procedure a) Three samples of aggregates weighing 2.5kg each are prepared.i. Aggregates passing 50mm BS sieve and retained on 37.5mm BSsieve.ii. ii. Aggregates passing 37.5mm BS sieve and retained on 28mm BSsieve.iii.iii. Aggregates passing 28mm BS sieve and retained on 20mm BSsieve.B)Each sample is gauge in turn of thickness on metal gauge.c. The passing material of each sample is weighed

PASSING SIEVE(mm)RETAINED SIEVE(mm)SAMPLE

(kg)PASSING

(kg)RETAINED(kg)FLAKINESS INDEX(%)ELONGATION INDEX(%)

201410.2064020.640

141010.095609.560

Calculation X 100

Flakiness index (%) = Nos. passing Total Nos. Aggregate = 0.2064X 100

1 = 20.64 %Average Flakiness Index (%) = Summation of all fractions No. of fractions = 20.64 + 9.56 2= 15.1%

Elongation index (%) = Nos. passing Total Nos. Aggregate = 0X 100

1 = 0%Average Elongation Index (%) = Summation of all fractions No. of fractions = 0 2= 0%

DiscussionThe value that we get from this test is 15.1% for flakiness and not exceeds 20% the JKR requirement. Elongation value is 0% because the aggregate is rounded so no any retain value. Aggregate quality for road construction will also influence the road performance. The flakiness and elongation rocks are not suitable for road construction because this type of rocks will make the road surface not balance and easy to damage

VISCOSITY PENETRATION TEST

OBJECTIVE To measure the viscosity of asphalt at application temperatures

APPARATUS1. Heater - A heater capable of maintaining any desired temperature setting from room temperature to 260C to within 3C.

1. ThermometersThermometers having a range from 60 to over 200C and readable to 0.2C.

1. Cylindrical spindles of various sizes for measurement of asphalt binders of different viscosities.1. Rotational Viscometer capable of measuring the torque required to rotate the selected constant speed while submerged in asphalt at constant desired test temperature and should display the viscosity in Pascal seconds automatically.1. Temperature Controller - A proportional temperature controller capable of maintaining the specimen temperatures t1.0C for test temperatures ranging from 60 to 165C or greater.

MATERIALSSolvent such as (Mineral Spirits or Varsol) or a degreasing spray cleaner formulated for cleaning the sample holder, spindles and accessories.

PROCEDURE1. Read and understand the information in the rotational viscometer manufacturer's operating manual before proceeding.1. Turn on the rotational viscometer and proportional temperature controller unit.1. Preheat the sample holder with the sample chamber and the selected cylindrical spindle according to the manufacturer's recommendation.

1. Set the proportional temperature controller to desired test temperature.

1. When the proportional temperature controller reads the desired test temperature, remove the sample holder, and add the required amount of asphalt into the sample chamber.1. Insert the sample chamber into the proportional temperature controller unit.

1. Insert a preheated spindle and attach it to the viscometer using the necessary coupling. Gently lower the spindle into the asphalt so that asphalt covers the upper conical portion of the spindle. This procedure may vary based on the manufacturer's recommendations.1. Bring the asphalt to the desired temperature within approximately 30 minutes. Set the viscometer speed at 20 rpm and set the display to the read viscosity in Pascal seconds (Pas). This operation may be done manually or by using a software program.1. Allow the asphalt sample to equilibrate at the desired test temperature for a minimum of 10 minutes. Begin the spindle rotation during the 10 minute temperature equilibration period. Allow' the readings to stabilize before recording any viscosity measurements. If the observed torque is out of range for the selected spindle and speed, change the spindle and or speed based on the manufacturer's recommendations for the anticipated viscosity. Restart the test with a new sample.1. Start the test after the asphalt sample has reached the specified temperature and equilibrated and the viscosity readings have stabilized.1. Measure the viscosity at one-minute intervals for a total of three minutes.

CONCLUSIONThe mixing temperature of bitumen is vital to determine the well mixing of the bitumen with the aggregate. Temperature affects the viscosity of bitumen, low temperature will result in bitumen with low viscosity which unable to mix well with aggregate to provide sufficient bonding between those two materials, which in the end affects the quality of the road surface layer laid with the material.Since the result obtained raised the concern about the material which been delivered to the laboratory may not fit the purchasing order. Since it does not fit the requirement of bitumen grade 80/100, this material is not suitable for any road surface layer construction.