VDOT Soils And Aggregate Compaction
TEST STUDY GUIDE 2026/2027 ACCURATE
QUESTIONS WITH CORRECT DETAILED
SOLUTIONS ||
100% GUARANTEED PASS
<NEWEST VERSION>
1. True or false: The voids in a saturated soil are partly filled with water and
partly filled with water. - ANSWER ✔ False. In a saturated soil, the voids
are entirely filled with water. (Zero Air Voids = ZAV)
2. What classification systems does VDOT use to classify soils? - ANSWER
✔ VDOT uses AASHTO and Unified Soil Classification Systems to
classify soils.
3. What term refers to the texture and firmness of a soil? - ANSWER ✔
Consistency refers to the texture and firmness of a soil.
4. Silts and clays are made of particles that are smaller than which sieve? -
ANSWER ✔ Silt and clay are made up of particles smaller than the No.
200 sieve (75 micrometers)
5. What term describes the distribution of various particle sizes with the
material? - ANSWER ✔ The gradation is the distribution of various
particle sizes within the material.
6. What term describes that the particles in a mixture are sized so that they fill
most of the voids and there is very little space in between soil or stone
particles? - ANSWER ✔ Dense graded means that the particles in the
mixture are sized do that they fill most of the voids; there is very little space
between the soil or stone particles.
,7. What is the moisture content at which soil begins to behave like a liquid
called? - ANSWER ✔ The moisture content at which a soil begins to
behave like a liquid is called the liquid limit.
8. What is the behavior of a material where the material deforms under load
and does not return to its original shape called? - ANSWER ✔ The
behavior of a material where the material deforms under load and does not
go back to its original shape is called plasticity.
9. What is the moisture content at which soil can be compacted to its maximum
dry density with the least amount of comparative effort called? - ANSWER
✔ The moisture content at which a soil can be compacted to its maximum
dry density with the least amount of comparative effort is called the
optimum moisture content.
10.Gravel Sieve - ANSWER ✔ #3-#10
11.Sand Sieve - ANSWER ✔ #10-#200
12.Fines Sieve - ANSWER ✔ #200+
13.Size - ANSWER ✔ Described by particle or grain diameter or average
dimension.
14.Shape - ANSWER ✔ The shape of the grains larger than .06 inches is
inditingusable to the naked eye
15.Surface Texture - ANSWER ✔ Refers to the degree of fineness and
uniformity of a soil.
16.Surface Forces - ANSWER ✔ fine grained platey soils, electrical forces on
the surface of the grains. important of how they react with water
17.Consistancy - ANSWER ✔ texture and firmness of soil
18.Cohesion - ANSWER ✔ The mutual attraction of particles due to
molecular forces and the present of moisture films
,19.Sensisitvity - ANSWER ✔ a characteristic of clays that describes the lose
of strngth after disturbance
20.moisture content - ANSWER ✔ how much moisture is in the void spaces
21.Why are dense grades used more for aggregate bases - ANSWER ✔ bc the
dense gradation provides more strength by filling voids
22.T or F - Cesium-137 is located in the tip of the stainless steel rod which is
used in taking moisture determinations and Americium-241:Beryllium is
located inside the nuclear gauge and is used for density testing - ANSWER
✔ False - Cesium-137 is located in the tip of the stainless steel rod and is
used for density determinations and the Americium-241:Beryllium is located
inside the gauge is used for moisture determinations
23.When taking Standard Counts the Reference Standard should be placed on
what type of surface? - ANSWER ✔ Smooth, flat, and dry surface with a
minimum density of 100 lb/cubic feet
24.What are the three differences between the AASHTO T-99 and AASHTO T-
180? - ANSWER ✔ The three differences between AASHTO T-99 and T-
180 are 1) the weight of the hammer, 2) the height of the hammer drop, and
3) the number of layers in soil compacted in the mold.
25.How many layers of soil are required to make a standard proctor mold? How
many blows does each layer require? How heavy should the hammer be?
How far should the hammer fall? - ANSWER ✔ Three layers are required
to make a standard proctor mold and each layer must be compacted with 25
blows with a 5.5 lb hammer dropped 12 inches.
26.What are the moisture and density content corresponding to the peak of the
curve termed? - ANSWER ✔ The moisture content corresponding to the
peak of the curve will be termed the optimum moisture content and the
density corresponding to the peak of the curve will be termed the maximum
dry density.
, 27.How many scoops of reagent are placed in the body of the speedy moisture
tester? - ANSWER ✔ Three scoops of reagent are placed in the body of the
speedy moisture tester.
28.According to AASHTO, how much should the base of the proctor test mold
weigh? - ANSWER ✔ According to AASHTO, the base on which the
proctor test molds are made must weigh at least 200 lbs.
29.What reading should the dial on the speedy exceed in order to warrant using
a half-size sample, and what should the new dial reading be? - ANSWER
✔ If the dial on the Speedy exceeds 20, a half size sample must be used
and the dial reading must be multiplied by 2.
30.Proctors are run on soil which passes through which sieve? - ANSWER ✔
The proctor is run on soil which passes the No. 4 sieve.
31.How much should you rotate the speedy? How long should the speedy rest?
Over what period should this be done? - ANSWER ✔ Rotate the Speedy
for 10 seconds, rest for 20 seconds for a period of 3 minutes.
32.Calculate the moisture content with the following:
W_wet=10.85,W_dry=10.05,W_con=1.69. - ANSWER ✔ The formula for
moisture content is W=(W_w-W_d)/(W_d-W_mold). (10.85-10.05)/(10.05-
1.69)=.0956 --> 9.6%.
33.What are the 3 ways to limit exposure to radiation? - ANSWER ✔ time,
distance, and shielding
34.What is the first step taken if the soil material fails a nuclear test because of
excessive moisture? - ANSWER ✔ Run another test, while checking test
methods to ensure they are correct
35.What is the testing method for testing densities whereby the source rod is
inserted into the material to be tested at a depth of 4, 6, or 8 inches -
ANSWER ✔ Direct Transmission Method
36.What should you do if, during construction, the density results either change
suddenly or simply don't make sense? - ANSWER ✔ Check your math and
TEST STUDY GUIDE 2026/2027 ACCURATE
QUESTIONS WITH CORRECT DETAILED
SOLUTIONS ||
100% GUARANTEED PASS
<NEWEST VERSION>
1. True or false: The voids in a saturated soil are partly filled with water and
partly filled with water. - ANSWER ✔ False. In a saturated soil, the voids
are entirely filled with water. (Zero Air Voids = ZAV)
2. What classification systems does VDOT use to classify soils? - ANSWER
✔ VDOT uses AASHTO and Unified Soil Classification Systems to
classify soils.
3. What term refers to the texture and firmness of a soil? - ANSWER ✔
Consistency refers to the texture and firmness of a soil.
4. Silts and clays are made of particles that are smaller than which sieve? -
ANSWER ✔ Silt and clay are made up of particles smaller than the No.
200 sieve (75 micrometers)
5. What term describes the distribution of various particle sizes with the
material? - ANSWER ✔ The gradation is the distribution of various
particle sizes within the material.
6. What term describes that the particles in a mixture are sized so that they fill
most of the voids and there is very little space in between soil or stone
particles? - ANSWER ✔ Dense graded means that the particles in the
mixture are sized do that they fill most of the voids; there is very little space
between the soil or stone particles.
,7. What is the moisture content at which soil begins to behave like a liquid
called? - ANSWER ✔ The moisture content at which a soil begins to
behave like a liquid is called the liquid limit.
8. What is the behavior of a material where the material deforms under load
and does not return to its original shape called? - ANSWER ✔ The
behavior of a material where the material deforms under load and does not
go back to its original shape is called plasticity.
9. What is the moisture content at which soil can be compacted to its maximum
dry density with the least amount of comparative effort called? - ANSWER
✔ The moisture content at which a soil can be compacted to its maximum
dry density with the least amount of comparative effort is called the
optimum moisture content.
10.Gravel Sieve - ANSWER ✔ #3-#10
11.Sand Sieve - ANSWER ✔ #10-#200
12.Fines Sieve - ANSWER ✔ #200+
13.Size - ANSWER ✔ Described by particle or grain diameter or average
dimension.
14.Shape - ANSWER ✔ The shape of the grains larger than .06 inches is
inditingusable to the naked eye
15.Surface Texture - ANSWER ✔ Refers to the degree of fineness and
uniformity of a soil.
16.Surface Forces - ANSWER ✔ fine grained platey soils, electrical forces on
the surface of the grains. important of how they react with water
17.Consistancy - ANSWER ✔ texture and firmness of soil
18.Cohesion - ANSWER ✔ The mutual attraction of particles due to
molecular forces and the present of moisture films
,19.Sensisitvity - ANSWER ✔ a characteristic of clays that describes the lose
of strngth after disturbance
20.moisture content - ANSWER ✔ how much moisture is in the void spaces
21.Why are dense grades used more for aggregate bases - ANSWER ✔ bc the
dense gradation provides more strength by filling voids
22.T or F - Cesium-137 is located in the tip of the stainless steel rod which is
used in taking moisture determinations and Americium-241:Beryllium is
located inside the nuclear gauge and is used for density testing - ANSWER
✔ False - Cesium-137 is located in the tip of the stainless steel rod and is
used for density determinations and the Americium-241:Beryllium is located
inside the gauge is used for moisture determinations
23.When taking Standard Counts the Reference Standard should be placed on
what type of surface? - ANSWER ✔ Smooth, flat, and dry surface with a
minimum density of 100 lb/cubic feet
24.What are the three differences between the AASHTO T-99 and AASHTO T-
180? - ANSWER ✔ The three differences between AASHTO T-99 and T-
180 are 1) the weight of the hammer, 2) the height of the hammer drop, and
3) the number of layers in soil compacted in the mold.
25.How many layers of soil are required to make a standard proctor mold? How
many blows does each layer require? How heavy should the hammer be?
How far should the hammer fall? - ANSWER ✔ Three layers are required
to make a standard proctor mold and each layer must be compacted with 25
blows with a 5.5 lb hammer dropped 12 inches.
26.What are the moisture and density content corresponding to the peak of the
curve termed? - ANSWER ✔ The moisture content corresponding to the
peak of the curve will be termed the optimum moisture content and the
density corresponding to the peak of the curve will be termed the maximum
dry density.
, 27.How many scoops of reagent are placed in the body of the speedy moisture
tester? - ANSWER ✔ Three scoops of reagent are placed in the body of the
speedy moisture tester.
28.According to AASHTO, how much should the base of the proctor test mold
weigh? - ANSWER ✔ According to AASHTO, the base on which the
proctor test molds are made must weigh at least 200 lbs.
29.What reading should the dial on the speedy exceed in order to warrant using
a half-size sample, and what should the new dial reading be? - ANSWER
✔ If the dial on the Speedy exceeds 20, a half size sample must be used
and the dial reading must be multiplied by 2.
30.Proctors are run on soil which passes through which sieve? - ANSWER ✔
The proctor is run on soil which passes the No. 4 sieve.
31.How much should you rotate the speedy? How long should the speedy rest?
Over what period should this be done? - ANSWER ✔ Rotate the Speedy
for 10 seconds, rest for 20 seconds for a period of 3 minutes.
32.Calculate the moisture content with the following:
W_wet=10.85,W_dry=10.05,W_con=1.69. - ANSWER ✔ The formula for
moisture content is W=(W_w-W_d)/(W_d-W_mold). (10.85-10.05)/(10.05-
1.69)=.0956 --> 9.6%.
33.What are the 3 ways to limit exposure to radiation? - ANSWER ✔ time,
distance, and shielding
34.What is the first step taken if the soil material fails a nuclear test because of
excessive moisture? - ANSWER ✔ Run another test, while checking test
methods to ensure they are correct
35.What is the testing method for testing densities whereby the source rod is
inserted into the material to be tested at a depth of 4, 6, or 8 inches -
ANSWER ✔ Direct Transmission Method
36.What should you do if, during construction, the density results either change
suddenly or simply don't make sense? - ANSWER ✔ Check your math and
