CFB Construction Techniques 2 — Questions and Answers
Question 1: When installing synthetic turf on an athletic field, what is the correct sequence for the base layers?
- Subgrade, drainage aggregate, stone base, turf surface (Correct answer)
- Stone base, subgrade, drainage aggregate, turf surface
- Drainage aggregate, subgrade, stone base, turf surface
- Turf surface, drainage aggregate, stone base, subgrade
Correct answer: Subgrade, drainage aggregate, stone base, turf surface
The correct sequence is compacted subgrade first, followed by drainage aggregate, then the stone base layer, and finally the turf surface.
Question 2: Which compaction method is most appropriate for fine-grained cohesive soils in field construction?
- Vibratory roller
- Sheepsfoot roller (Correct answer)
- Pneumatic tire roller
- Smooth drum roller
Correct answer: Sheepsfoot roller
Sheepsfoot rollers are designed for cohesive fine-grained soils because their protruding feet knead and densify clay-rich materials effectively.
Question 3: What is the primary purpose of a perimeter drain system installed around a sports field?
- To supply irrigation water to the field
- To intercept and remove groundwater and surface runoff (Correct answer)
- To regulate soil temperature in the root zone
- To prevent frost heaving during winter months
Correct answer: To intercept and remove groundwater and surface runoff
Perimeter drains intercept groundwater from surrounding areas and collect surface runoff to keep the field drainage system from being overwhelmed.
Question 4: When constructing a sand-based root zone for a golf green, what is the typical depth specification?
- 4 to 6 inches
- 8 to 12 inches (Correct answer)
- 14 to 16 inches
- 18 to 24 inches
Correct answer: 8 to 12 inches
USGA-method golf greens specify a sand root zone of 12 inches in depth to provide adequate drainage while supporting healthy turfgrass roots.
Question 5: In field construction, what does 'subgrade preparation' primarily involve?
- Installing the irrigation system below grade
- Shaping and compacting native or imported soil to the design grade (Correct answer)
- Applying seed or sod to the prepared surface
- Installing drainage tile in trenches
Correct answer: Shaping and compacting native or imported soil to the design grade
Subgrade preparation involves grading and compacting the soil foundation layer to the designed slopes and elevations before any base materials are placed.
Question 6: Which type of geotextile fabric is typically used beneath drainage aggregate in field construction to prevent soil migration?
- Woven geotextile with low permeability
- Non-woven geotextile with appropriate AOS rating (Correct answer)
- Impermeable geomembrane liner
- Reflective thermal barrier fabric
Correct answer: Non-woven geotextile with appropriate AOS rating
Non-woven geotextiles with an appropriate Apparent Opening Size (AOS) allow water passage while filtering soil particles to prevent aggregate contamination.
Question 7: What is the recommended maximum slope for a natural grass athletic field to ensure adequate drainage without causing playability issues?
- 0.25%
- 1.0%
- 2.0% (Correct answer)
- 4.0%
Correct answer: 2.0%
A 2% maximum slope (1:50) balances effective surface drainage with safe and level playability conditions for most athletic field applications.
CFB Construction Techniques 2
When installing synthetic turf on an athletic field, what is the correct sequence for the base layers?