1|Page
EXAC Section 3: Final Project 2025 | Real
Exam Questions With Answers
What is: Design wind pressure? - correct -answer-Design wind pressure:
Minimum design value for the equivalent static pressure on the exterior surfaces
resulting from critical wind velocity (equal to a reference wind wind pressure
measured at 33', 10m). The # is modified by a bunch of coefficients to account for:
exposure conditions, building height, wind gusts, geometry/orientation.
Why are horizontal forces more critical than vertical ones in seismic design? -
correct -answer-Because structures usually have considerable reserve for dealing
with additional vertical loads.
Define Base Shear. - correct -answer-Base shear:
Minimum design value for the total lateral seismic force (assumed to act in any
horizontal direction)
Define the following: Collinear Forces, Concurrent Forces, Nonconcurrent Forces. -
correct -answer-Collinear Forces:
,2|Page
Occur along straight line. Vector sum= sum of magnitude of forces acting along
same line of action.
List 4 ways to help reduce the the sound transmission of equipment. - correct -
answer-1. Block flanking paths that transmit sound through plenum spaces
(ductwork/piping), vibration/sound dampers in ductwork
2. Use Resilient mountings and flexible bellows to isolate equip vibrations from
bldg struct and supply systems to reduce transmission of vibration and noise to
supporting struct
3. Inertia Block - heavy concrete base for vibration isolators to increase the mass
of equip and decrease the potential for vibratory movement
4. Select mech equip with low sone ratings:
Sone - subjective unit of loudness which is equal to a 1000Hz reference sound
with an intensity of 40d
List the 2 main types of sound sources in regards to transfer between rooms/suits,
and how they are mitigated (simple). - correct -answer-1. Airborne
Mitigated with mass/insulation/isolation
2. Impact
Mitigated with discontinuity of bldg materials
,3|Page
What is Apparent sound transmission? Provide examples for each of the 2
contributing factors. - correct -answer-Apparent transmission:
Direct transmission+Flanking Transmission
Direct=sound through through wall (STC ratings)
Factors in direct transmission: Insulation, mass
Flanking=sound going around wall (ie through floor/wall connection)
Factors in Flanking Transmission: Joist Direction, Floor Topping, Continuity of sub-
floor through wall
What 3 basic components make up concrete? - correct -answer-Cement, water,
Aggregate
What are each of the 5 types of Portland cement used for? - correct -answer-Type
I - normal - used for general construction
Type II - moderate - used for general construction where resistance to moderate
sulfate action is required, or where heat buildup can be damaging (ie large piers
and heaving retaining walls)
Type III - high-early-strength cement cures faster and gains strength faster than
normal cement. Used when early removal of formwork is desired, or cold-weather
construction to reduce time required for heat protection
, 4|Page
Type IV - low-heat cement - generates less heat of hydration than normal portland
cement. Used in construction of massive concrete structures (ie gravity dams)
where large heat buildup can be damaging
Type V - sulfate resisting - required when resistance to severe sulfate action is
required
What % of concrete volume is aggregate (roughly)? What are properties are
aggregate important to in the final product? - correct -answer-60-80%
-Strength
-Weight
-Fire -resistance
Describe the differences between Coarse and Fine aggregate. - correct -answer-
Fine Aggregate - sand with particle sizes <¼"
Coarse Aggregate - crushed stone/gravel/blast furnace slag with particle sizes >¼"
Max size of coarse aggregate in reinforced concrete is limited by the size of the
section and spacing of reinforcing bars
Explain what the following admixtures do:
1. Air-entraining agents
EXAC Section 3: Final Project 2025 | Real
Exam Questions With Answers
What is: Design wind pressure? - correct -answer-Design wind pressure:
Minimum design value for the equivalent static pressure on the exterior surfaces
resulting from critical wind velocity (equal to a reference wind wind pressure
measured at 33', 10m). The # is modified by a bunch of coefficients to account for:
exposure conditions, building height, wind gusts, geometry/orientation.
Why are horizontal forces more critical than vertical ones in seismic design? -
correct -answer-Because structures usually have considerable reserve for dealing
with additional vertical loads.
Define Base Shear. - correct -answer-Base shear:
Minimum design value for the total lateral seismic force (assumed to act in any
horizontal direction)
Define the following: Collinear Forces, Concurrent Forces, Nonconcurrent Forces. -
correct -answer-Collinear Forces:
,2|Page
Occur along straight line. Vector sum= sum of magnitude of forces acting along
same line of action.
List 4 ways to help reduce the the sound transmission of equipment. - correct -
answer-1. Block flanking paths that transmit sound through plenum spaces
(ductwork/piping), vibration/sound dampers in ductwork
2. Use Resilient mountings and flexible bellows to isolate equip vibrations from
bldg struct and supply systems to reduce transmission of vibration and noise to
supporting struct
3. Inertia Block - heavy concrete base for vibration isolators to increase the mass
of equip and decrease the potential for vibratory movement
4. Select mech equip with low sone ratings:
Sone - subjective unit of loudness which is equal to a 1000Hz reference sound
with an intensity of 40d
List the 2 main types of sound sources in regards to transfer between rooms/suits,
and how they are mitigated (simple). - correct -answer-1. Airborne
Mitigated with mass/insulation/isolation
2. Impact
Mitigated with discontinuity of bldg materials
,3|Page
What is Apparent sound transmission? Provide examples for each of the 2
contributing factors. - correct -answer-Apparent transmission:
Direct transmission+Flanking Transmission
Direct=sound through through wall (STC ratings)
Factors in direct transmission: Insulation, mass
Flanking=sound going around wall (ie through floor/wall connection)
Factors in Flanking Transmission: Joist Direction, Floor Topping, Continuity of sub-
floor through wall
What 3 basic components make up concrete? - correct -answer-Cement, water,
Aggregate
What are each of the 5 types of Portland cement used for? - correct -answer-Type
I - normal - used for general construction
Type II - moderate - used for general construction where resistance to moderate
sulfate action is required, or where heat buildup can be damaging (ie large piers
and heaving retaining walls)
Type III - high-early-strength cement cures faster and gains strength faster than
normal cement. Used when early removal of formwork is desired, or cold-weather
construction to reduce time required for heat protection
, 4|Page
Type IV - low-heat cement - generates less heat of hydration than normal portland
cement. Used in construction of massive concrete structures (ie gravity dams)
where large heat buildup can be damaging
Type V - sulfate resisting - required when resistance to severe sulfate action is
required
What % of concrete volume is aggregate (roughly)? What are properties are
aggregate important to in the final product? - correct -answer-60-80%
-Strength
-Weight
-Fire -resistance
Describe the differences between Coarse and Fine aggregate. - correct -answer-
Fine Aggregate - sand with particle sizes <¼"
Coarse Aggregate - crushed stone/gravel/blast furnace slag with particle sizes >¼"
Max size of coarse aggregate in reinforced concrete is limited by the size of the
section and spacing of reinforcing bars
Explain what the following admixtures do:
1. Air-entraining agents
