ACI AGGREGATE TESTING TECHNICIAN
EXAMPREP STUDY GUIDE 2026 DETAILED
QUESTIONS AND CORRECT ANSWERS
GRADED A+
●● AASHTO T 96 LA Machine Small-Size Course Agg.
2. The aggregate tested in the Los Angeles Machine is subjected to such
actions as _________, ________., ________., and ________ Answer:
Abrasion, attrition, impact, grinding.
●● AASHTO T 96 LA Machine Small-Size Course Agg.
3. What promotes the degradation of the aggregates in the rotating steel
drum? Answer: Steel spheres
●● AASHTO T 96 LA Machine Small-Size Course Agg.
4. This test indicates the relative _________ or __________ of
aggregates composed of similar _________ Answer: Quality or
competence; minerals
●● AASHTO T 96 LA Machine Small-Size Course Agg.
,5. The Los Angeles Machine consists of a hollow ____________, with
an opening for the introduction of the test sample, a dust-tight ______,
and a ___________ shelf. Answer: Steel cylinder; cover; removable
steel
●● AASHTO T 96 LA Machine Small-Size Course Agg.
6. A shelf of wear-resistant steel, rectangular in cross section, and
mounted on the cover, is preferred. True or False? Answer: False, a shelf
mounted independently of the cover is preferred.
●● AASHTO T 96 LA Machine Small-Size Course Agg.
7. A _________ , __________ speed must be maintained. Answer:
Uniform, peripheral
●● AASHTO T 96 LA Machine Small-Size Course Agg.
8. The steel spheres should be 31.8 mm (1-1/4 in.) in diameter and have
a mass of 320 g. True or False? Answer: False; they should average 46.8
mm (1-27/32 in.) and have a mass between 390 and 445 g.
,●● AASHTO T 96 LA Machine Small-Size Course Agg.
9. If grading B is used, ____ spheres are needed. Answer: 11
●● AASHTO T 96 LA Machine Small-Size Course Agg.
10. After the test sample and steel spheres are in the machine, rotate the
drum at __ to __ r/min. for ____ revolutions. Answer: 30-33 r/min for
500 revolutions.
●● AASHTO T 96 LA Machine Small-Size Course Agg.
11. After the required revolutions, separate the material using a
______________ Answer: 1.70 mm sieve (No. 12 sieve)
●● AASHTO T 96 LA Machine Small-Size Course Agg.
12. The _______ material that remains after sieving, should be oven-
dried to ______ Answer: Coarse; substantially constant mass
●● AASHTO T 96 LA Machine Small-Size Course Agg.
, 13. Computing the ratio of loss after 100 revolutions to the loss after
500, may offer valuable information regarding the uniformity of the test
sample. True or False? Answer: True
●● AASHTO T 96 LA Machine Small-Size Course Agg.
14. The difference between the original mass of the test sample and the
final mass should be reported as a percent of the ___________________
. This is the percent loss. Answer: Original mass
●● AASHTO T 96 LA Machine Small-Size Course Agg.
15. The results of properly conducted tests run by different laboratories
on the same coarse aggregates are not expected to differ by more than
____ % of their average. Answer: 12.7
●● ASTM C535 LA Machine Large-Size Course Agg.
1. This test method covers all aggregate larger than 10 mm (3/8 in.).
True or False? Answer: False; larger than 19 mm (3/4 in.)
●● ASTM C535 LA Machine Large-Size Course Agg.
EXAMPREP STUDY GUIDE 2026 DETAILED
QUESTIONS AND CORRECT ANSWERS
GRADED A+
●● AASHTO T 96 LA Machine Small-Size Course Agg.
2. The aggregate tested in the Los Angeles Machine is subjected to such
actions as _________, ________., ________., and ________ Answer:
Abrasion, attrition, impact, grinding.
●● AASHTO T 96 LA Machine Small-Size Course Agg.
3. What promotes the degradation of the aggregates in the rotating steel
drum? Answer: Steel spheres
●● AASHTO T 96 LA Machine Small-Size Course Agg.
4. This test indicates the relative _________ or __________ of
aggregates composed of similar _________ Answer: Quality or
competence; minerals
●● AASHTO T 96 LA Machine Small-Size Course Agg.
,5. The Los Angeles Machine consists of a hollow ____________, with
an opening for the introduction of the test sample, a dust-tight ______,
and a ___________ shelf. Answer: Steel cylinder; cover; removable
steel
●● AASHTO T 96 LA Machine Small-Size Course Agg.
6. A shelf of wear-resistant steel, rectangular in cross section, and
mounted on the cover, is preferred. True or False? Answer: False, a shelf
mounted independently of the cover is preferred.
●● AASHTO T 96 LA Machine Small-Size Course Agg.
7. A _________ , __________ speed must be maintained. Answer:
Uniform, peripheral
●● AASHTO T 96 LA Machine Small-Size Course Agg.
8. The steel spheres should be 31.8 mm (1-1/4 in.) in diameter and have
a mass of 320 g. True or False? Answer: False; they should average 46.8
mm (1-27/32 in.) and have a mass between 390 and 445 g.
,●● AASHTO T 96 LA Machine Small-Size Course Agg.
9. If grading B is used, ____ spheres are needed. Answer: 11
●● AASHTO T 96 LA Machine Small-Size Course Agg.
10. After the test sample and steel spheres are in the machine, rotate the
drum at __ to __ r/min. for ____ revolutions. Answer: 30-33 r/min for
500 revolutions.
●● AASHTO T 96 LA Machine Small-Size Course Agg.
11. After the required revolutions, separate the material using a
______________ Answer: 1.70 mm sieve (No. 12 sieve)
●● AASHTO T 96 LA Machine Small-Size Course Agg.
12. The _______ material that remains after sieving, should be oven-
dried to ______ Answer: Coarse; substantially constant mass
●● AASHTO T 96 LA Machine Small-Size Course Agg.
, 13. Computing the ratio of loss after 100 revolutions to the loss after
500, may offer valuable information regarding the uniformity of the test
sample. True or False? Answer: True
●● AASHTO T 96 LA Machine Small-Size Course Agg.
14. The difference between the original mass of the test sample and the
final mass should be reported as a percent of the ___________________
. This is the percent loss. Answer: Original mass
●● AASHTO T 96 LA Machine Small-Size Course Agg.
15. The results of properly conducted tests run by different laboratories
on the same coarse aggregates are not expected to differ by more than
____ % of their average. Answer: 12.7
●● ASTM C535 LA Machine Large-Size Course Agg.
1. This test method covers all aggregate larger than 10 mm (3/8 in.).
True or False? Answer: False; larger than 19 mm (3/4 in.)
●● ASTM C535 LA Machine Large-Size Course Agg.
