ETC ETC Construction Methods & Field Operations 1 — Questions and Answers
Question 1: What is the purpose of a shoring system during excavation?
- To compact soil at the bottom of the excavation
- To support the walls of an excavation and prevent collapse (Correct answer)
- To dewater the excavation area
- To measure the depth of the excavation
Correct answer: To support the walls of an excavation and prevent collapse
Shoring systems support the sides of an excavation to prevent cave-in and protect workers from soil collapse.
Question 2: What does the term 'subgrade' refer to in road construction?
- The finished asphalt surface layer
- The native or prepared soil layer below the pavement structure (Correct answer)
- The aggregate base course above the soil
- The drainage layer beneath the pavement
Correct answer: The native or prepared soil layer below the pavement structure
Subgrade is the compacted native or improved soil layer that forms the foundation for the pavement structure above.
Question 3: What is the purpose of a slump test for concrete?
- To measure concrete compressive strength
- To assess the workability and consistency of fresh concrete mix (Correct answer)
- To determine the water-cement ratio
- To check concrete air content
Correct answer: To assess the workability and consistency of fresh concrete mix
The slump test measures how much a cone of fresh concrete settles under its own weight, indicating its workability and water content.
Question 4: What is the function of rebar in concrete structures?
- To reduce the weight of concrete members
- To provide tensile strength that concrete lacks on its own (Correct answer)
- To improve thermal insulation of the structure
- To speed up concrete curing time
Correct answer: To provide tensile strength that concrete lacks on its own
Rebar provides tensile and flexural strength to concrete, which is strong in compression but weak in tension.
Question 5: What does compaction of fill material achieve in construction?
- Reduces the cost of materials needed
- Increases soil density and bearing capacity while reducing future settlement (Correct answer)
- Improves drainage through the fill layer
- Removes organic material from the fill
Correct answer: Increases soil density and bearing capacity while reducing future settlement
Compaction increases the dry density of soil by reducing air voids, improving load-bearing capacity and minimizing future settlement.
Question 6: What is a shop drawing in construction?
- A sketch made by the field superintendent
- A detailed drawing prepared by a contractor or fabricator showing how they will build a specific element (Correct answer)
- The original design drawings issued for construction
- A drawing of the site layout for the contractor's use
Correct answer: A detailed drawing prepared by a contractor or fabricator showing how they will build a specific element
Shop drawings are detailed fabrication and installation drawings prepared by contractors or suppliers showing exact dimensions, materials, and methods.
ETC ETC Construction Methods & Field Operations 1
What is the purpose of a shoring system during excavation?