An asphalt concrete cylindrical specimen with a 4-inch diameter and a 6-inch height is subjected to an axial compressive static load of 150 lb for 1 hour after which the load is removed. The test was performed at a temperature of 100°F. The height of the specimen was measured at different time intervals during loading and unloading for a total of 2 hours and produced the following results:
|
Time, minutes
|
Specimen Height, inches
|
Time, minutes
|
Specimen Height, inches
|
|
0
|
6.0000
|
60.01
|
5.9772
|
|
0.01
|
5.9916
|
62
|
5.9807
|
|
2
|
5.9870
|
65
|
5.9841
|
|
5
|
5.9833
|
70
|
5.9879
|
|
10
|
5.9796
|
80
|
5.9926
|
|
20
|
5.9753
|
90
|
5.9942
|
|
30
|
5.9725
|
100
|
5.9954
|
|
40
|
5.9708
|
110
|
5.9959
|
|
50
|
5.9696
|
120
|
5.9964
|
|
60
|
5.9688
|
|
|
a. Using a spreadsheet program, plot the stress versus time and the strain versus time on two separate graphs.
b. How much is the elastic strain?
c. What is the permanent strain at the end of the experiment?
d. What is the phenomenon of the change of specimen height during static loading called? What is the phenomenon of the change of specimen height during unloading called?