Question

on ral allofit An asphalt concretecylindrical specimen with a diameter di 4.1 in and a height hi5.999 in was subjected to an axial compressive static load P158 lb for 1 hour after which time the load was removed. The test was performed at a temperature of T102 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 results in the table below. Strein a. Using a spreadsheet program, plot the Stress versus(time and the strain versus time on separate graphs. Time Height Load Strecs6 Ib2 (min) (in) (b) 6,44 0 5.9990 158 b. How much is the elastic strain? 0.01 5.9910 158 2 158 5.987 c. What is the permanent strain at the end of the experiment? 5 5.9833 158 10 5.9796 d. What is the phenomenon of the change in specimen height during static loading called? 158 20 5.9753 158 30 5.9725 158 e. What is the phenomenon of the change of specimen height during unloading called? 40 5.9708 158 50 5.9696 158 otress 60 5.9688 158 cu)2 60.01 5.9772 0 62 5.9807 o.OY56713- 3667 b elashie strun 65 5.9841 0 70 5.9879 O.00o 80 5.9926 90 5.9942 0 0 000 3067 100 5.9954 0 110 5.9959 0 Colled cree" 120 5.9968 0 e) eloshe recoves

Answer 1

Solution friven data diameter of specimendia 4.1 height of specimen Ama 5.999 in Static load p = 158 lb After I hour load is removed a) we know that Stress - Load applied on specimen Area of crossection of cylindrical sperme Area of cylindrical Specimen = I diameter *4.12 = 13.202 in² stresse 158 -11.967 eblenz After 13.202 o the stress oeblin = 13.202 load is applied same for Since for her thor and cross and cross- sectional area is same. Stress remains fame. By drawing graph between stress and stain we get stress h 200 (eblap) 11.9676 TI Oslo 20 30 40 50 DO 20 los 100 1o De time (min) Note since x-aris It is time is known so it is taken where as stress is alculated taken on Y-axis- on quantity

Graph between strain and time straro = change in dimension Original dimension instiat height - fanal height initial height At t=0, strain = 5-999 -5.999 - 5.999 At tool, strain =5-999-5-90121-33x103 5-999 At t=2 train - 5.999-5.987 = 2x103 5.999 To the similar way strain with respect to triven time are 2.68 10 2-62x 103, 3.33x103, 3.958103, 44x103, 47X103, 4.9x103, 5 x 103, 3:68.103 3:05XB 205x103, 1:85X.103, 10 FX103, 08 x 103, 0-6x103, 0:5 x 103 and 0. 378103 straint ( n) 5x103 4x403 3x10 zx10² 001 s 10 20 30 40 50 60 70 So 90 100 110 120 time (min

o permanent strain Original height - final height Original height 1999-5-9968 5.999 0 3667X10 LA

curve (in b) Elastic Strain: The straid upto which the graph stran vs time] is linear - from graph, Elastic strain = 1.33X503 d) The The height phenomenon during phe of static change in loading specimen is called creep e since the specimen is elastic while unloading due to strain energy stored in it helps to recover some height. Hence this Phenomenon is called elastic recovery.