Question

8. The impact value test has been explained in the video demonstration as available at the BB unit site. Do you think all the groups will get the same value of impact value of the aggregate? Justify your answer.

9. You have prepared the laboratory test report for all the tests as planned for this unit, and so you have now enough experience of conducting the tests. In future, you may establish your own pavement consultancy company. Write the proper order of tests in decreasing importance as you may need to prepare for the clients. Also, provide the cost in AUD of each test as you would like to charge for these tests, including GST. Practical task 1: Determine the particle density and water absorption of coarse aggregate by weighing-in-water method. Practical tasks 2: Determine the impact value of the pavement aggregate.Practical tasks 3: Determine the Los Angeles value of the pavement aggregate.

11. Is there any relationship between the particle density and specific gravity of aggregate particles? Explain briefly.

Answer 1

8) All samples will not get the same impact value of aggregate.

Reason: Impact value of aggregate is determined by laboratory test known as Aggregate impact Test.

• This test is carried out by taking random samples of aggregates.
• Samples are tested in an apparatus. Apparatus mainly contains steel cylinder to hold sample and free fall hammer to apply impact.
• Test procedure consist careful sampling, placing of samples in cylinder by ramming, initial weight calculation, applying free fall load (15 blows ), final weight calculation after seiving
• Hence errors may occurs in every stage of test such as personal error, systematic errors etc
• Impact value also depends on parent rock from which aggregate originated.