Reference no: EM132416437
American University of Sharjah Department of Civil Engineering
CVE-221 Construction Materials and Quality Control
Question 1: As a materials engineer working for highway department, what standard PG asphalt binder grade would you specify for each of the conditions shown in Table below (show all calculations and fill in the last two columns of the table)
|
Case
|
Seven-day Maximum Pavement Temperature oC
|
Minimum Pavement Temperature oC
|
Recommended PG Grade
|
|
Mean, oC
|
Std. Dev.*, oC
|
Mean, oC
|
Std. Dev., oC
|
95% Reliability
|
98% Reliability
|
|
1
|
43
|
1.5
|
-29
|
2.5
|
|
|
|
2
|
51
|
3
|
-18
|
4
|
|
|
|
3
|
62
|
2.5
|
10
|
2
|
|
|
Std. Dev. = standard deviation
Question 2: As part of mix design, a laboratory-compacted cylindrical asphalt specimen is weighed for determination of bulk specific gravity. The following numbers are obtained:
o Dry Mass in air = 1264.7 grams
o Mass when submerged in water = 723.9 grams
o Mass of Saturated Surface Dry (SSD) = 1271.9 grams
Determine the following:
a) What is the bulk specific gravity of the compacted specimen (Gmb)?
b) If the maximum theoretical specific gravity of the specimen (Gmm) is 2.531, what would be the air void content of the specimen in percent?
Question 3: An aggregate blend is composed of 59% coarse aggregate by weight (Sp. Gr. 2.635), 36% fine aggregate (Sp. Gr. 2.710), and 5% filler (Sp. Gr. 2.748). The compacted specimen contains 6% asphalt binder (Sp. Gr. 1.088) by weight of the total mix, and has a bulk density of 143.9 lb/ft3. Ignoring absorption, compute the percent voids in the total mix (VTM), percent voids in mineral aggregates (VMA), and the percent voids filled with asphalt (VFA).
Question 4: Based on data shown in table below, select the blend for a Superpave design aggregate structure. Assume < 0.3 million ESAL and 19 mm nominal maximum aggregate size.
|
Data
|
Blend
|
|
1
|
2
|
3
|
|
Gmb
|
2.451
|
2.465
|
2.467
|
|
Gmm
|
2.585
|
2.654
|
2.584
|
|
Gb
|
1.030
|
1.030
|
1.030
|
|
Pb
|
5.9
|
5.5
|
5.8
|
|
Ps
|
94.1
|
94.5
|
94.2
|
|
Pd
|
4.5
|
4.5
|
4.5
|
|
Gsb
|
2.657
|
2.667
|
2.705
|
|
Hini
|
127
|
135
|
124
|
|
Hdes
|
113
|
114
|
118
|
Question 5: A steel pipe having a length of 1 m, an outside diameter of 0.2 m, and a wall thickness of 10 mm, is subjected to an axial compression of 200 kN. Assuming a modulus of elasticity of 200 GPa and a Poisson's ratio of 0.3, find the following:
(a) the shortening of the pipe
(b) the increase in outside dimeter