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Engineering Technician

NICET Construction Materials Testing Soils Level III Exam Practice Test

Soils construction materials testing examines how soil composition, moisture, density, and volume relationships affect behavior in earthwork. This practice page covers concepts reflected in questions about Atterberg limits, void ratio, relative density, permeability, specimen preservation, and triaxial testing. These measurements help technicians characterize soils and interpret laboratory observations used in construction materials evaluation.

Exam overview

Exam providerNational Institute for Certification in Engineering Technologies
Exam codeNot listed
CategoryEngineering Technician

About the NICET Construction Materials Testing Soils Level III Exam

Soil testing requires connecting measured properties to how a specimen behaves under controlled conditions. Questions address calculations such as plasticity index and void ratio, interpretation of plasticity-chart positions, and the meaning of relative density for granular soils. They also explore moisture-sensitive handling, including why cohesive samples are sealed after recovery, and the physical meaning of permeability. Triaxial-test scenarios focus on saturation, back pressure, drainage conditions, and volume constraints during shearing. Together, these concepts support careful test setup, recognition of specimen changes, interpretation of results, and clear communication of soil characteristics relevant to construction quality work.

Sample Practice Questions

Review a selection from this exam's published US Practice Tests practice bank.

Question 1

A technician observes that a soil specimen becomes visibly lighter in color and develops cracks as it dries. What is the most appropriate interpretation for quality control?

  1. AVisual appearance alone is sufficient to establish its water content
  2. BThe specimen should be checked using the specified measurement procedure rather than judged by appearance alone
  3. CCracking proves the soil has reached its shrinkage limit
  4. DColor change establishes that all organic matter has been removed
Show answerCorrect answer: B

Color and cracking may be observations, but they do not provide a reliable quantitative determination of water content or a specific consistency limit. Use the prescribed test method and measurements for those determinations.

Question 2

In an unconsolidated-undrained triaxial test on saturated clay, what does the term “undrained” mean during the shearing stage?

  1. AThe specimen is not allowed to change volume by drainage of pore water
  2. BThe confining pressure is held at zero
  3. CThe specimen is allowed to drain until excess pore pressure disappears
  4. DThe axial load is applied without measuring deformation
Show answerCorrect answer: A

In an undrained shearing stage, drainage is prevented, so water cannot enter or leave the specimen during that stage. In saturated soil this is commonly associated with essentially constant specimen volume, although pore-water pressure may change.

Question 3

A soil's Atterberg-limit data are plotted on a plasticity chart. What is the primary purpose of plotting the data relative to the A-line?

  1. ATo help distinguish clay-like from silt-like plasticity behavior for classification
  2. BTo determine the soil's in-place dry density directly
  3. CTo calculate the soil's coefficient of permeability
  4. DTo identify the mineral specific gravity without testing
Show answerCorrect answer: A

The plasticity chart uses liquid limit and plasticity index; position relative to the A-line is a classification aid for distinguishing clay-like and silt-like behavior. It does not directly provide density, permeability, or mineral specific gravity.

Question 4

A soil description reports a liquid limit of 42 and a plastic limit of 24. What is its plasticity index?

  1. A18
  2. B24
  3. C42
  4. D66
Show answerCorrect answer: A

The plasticity index is the liquid limit minus the plastic limit: 42 − 24 = 18. It represents the range of water contents over which the soil behaves plastically.

Question 5

A soil has a coefficient of permeability that is reported in units of length per time. What physical property does this coefficient describe?

  1. AThe soil’s ability to transmit water through its interconnected pores
  2. BThe soil’s resistance to shearing along a failure plane
  3. CThe rate at which solid particles settle in still water
  4. DThe amount of water held at the plastic limit
Show answerCorrect answer: A

Hydraulic conductivity, often called the coefficient of permeability in soil testing, characterizes how readily water flows through interconnected soil voids under a hydraulic gradient. It is distinct from shear strength, particle settling rate, and consistency limits.

Question 6

A cohesive soil sample is wrapped and sealed immediately after recovery from a boring. What is the principal reason for limiting moisture loss before laboratory testing?

  1. ATo preserve the sample's in-place moisture condition as much as practicable
  2. BTo increase the sample's particle specific gravity
  3. CTo prevent all future changes in soil structure during handling
  4. DTo make the sample meet a predetermined liquid limit
Show answerCorrect answer: A

Sealing helps limit evaporation and preserve the moisture condition present at recovery. It cannot eliminate all disturbance, but moisture loss can substantially alter consistency and test behavior.

Question 7

A soil specimen is saturated under a back pressure before a drained triaxial test. What is the main purpose of applying back pressure?

  1. ATo help dissolve or compress trapped air and improve saturation of the specimen
  2. BTo increase the specimen’s dry density without changing its volume
  3. CTo prevent measurement of pore-water pressure
  4. DTo eliminate the need to apply confining pressure
Show answerCorrect answer: A

Back pressure raises pore-water pressure and helps bring any remaining air into solution, improving saturation. It does not replace the confining pressure or inherently densify the specimen, and pore pressure may still be measured as required by the test.

How to use this practice test

The free practice bank contains 50 questions; each session presents up to 20 randomly selected questions. Answer a session to check your understanding of soil-property calculations, specimen handling, and laboratory test concepts, then review the results to identify topics that need closer attention.

Preparation tips

  • Calculate plasticity index from liquid-limit and plastic-limit values, and practice interpreting a point’s position relative to the A-line on a plasticity chart.
  • Review soil phase relationships and distinguish void ratio from other volume measures; work through examples using total volume and volume of solids.
  • Compare drained and undrained triaxial conditions, including the purpose of saturation back pressure and the effect of a constant-volume stage.
  • Relate permeability units of length per time to water flow through soil, and distinguish relative density near zero from a dense granular state.
  • Practice identifying how drying, cracking, or moisture loss can affect specimen condition and the interpretation of laboratory results.
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