CTQP Earthwork Construction Inspection 5

Question 1

A nuclear density gauge reading shows 95% relative compaction, but the soil feels soft underfoot. What should the inspector do next?

Accepted Answer

Request a sand cone verification test to confirm the gauge reading

Answer

When field observations conflict with gauge readings, a verification test such as the sand cone method should be performed to confirm or dispute the nuclear gauge result.

Question 2

What is the primary purpose of proof rolling a completed subgrade prior to base course placement?

Accepted Answer

To identify localized soft or unstable areas not detected by density testing

Answer

Proof rolling with a loaded tandem-axle truck identifies soft spots and areas of instability that point density tests may miss due to their small sample area.

Question 3

Which of the following best describes 'optimum moisture content' as used in earthwork compaction?

Accepted Answer

The moisture content at which a given soil achieves its maximum dry density under a specific compaction effort

Answer

Optimum moisture content (OMC) is defined by the Proctor test as the moisture level at which maximum dry density is achieved for a specific compactive effort.

Question 4

An inspector finds that borrow material delivered to the site contains roots, stumps, and organic debris. What is the correct action?

Accepted Answer

Reject the material and require the contractor to use conforming fill

Answer

Organic debris decomposes over time, causing long-term settlement; non-conforming material must be rejected and replaced with approved embankment material.

Question 5

During a Florida rainy season, an inspector must evaluate when earthwork operations can resume after rainfall. Which condition must be met before compaction restarts?

Accepted Answer

In-place moisture is within the specification window relative to optimum

Answer

Resuming compaction requires the in-place moisture to be within the specified range of optimum, not just visually dry, because surface appearance does not reflect subsurface moisture.

CTQP - Construction Training & Qualification Program Practice Test

CTQP - Construction Training & Qualification Program Practice Test

CTQP Earthwork Construction Inspection 5