West Virginia Concrete Contractor Examination

Under the West Virginia Concrete Contractor classification (the trade examination, not the Contractor Licensing Act examination), which wall work is inside the license definition?

• AAny height structural basement wall and any height site retaining wall
• BDecorative concrete walls not over 4 feet and retaining walls not over 5 feet, plus incid…
• COnly stamped patio slabs; walls of any kind require a masonry license
• DRetaining walls up to 10 feet if they are unreinforced

When converting a takeoff from cubic feet to cubic yards of concrete, which conversion is correct?

• A1 cubic yard equals 9 cubic feet
• B1 cubic yard equals 12 cubic feet
• C1 cubic yard equals 27 cubic feet
• D1 cubic yard equals 36 cubic feet

On a foundation plan, reinforcing noted as "#4 bars at 12 in. o.c. each way" means the bars are placed:

• A12 inches on center in both directions
• B12 inches from the form face only
• C12 inches of lap at every splice
• Da single #4 bar every 12 feet

A structural note states "f'c = 4,000 psi at 28 days." What does f'c represent?

• AThe slump measured at the truck chute
• BThe air content required for freeze-thaw exposure
• CThe modulus of elasticity of the coarse aggregate
• DThe specified compressive strength of the concrete

A slab-on-grade measures 24 feet by 36 feet and is 4 inches thick. How many cubic yards of concrete are required for the net volume, with no waste added?

• A10.7 cubic yards
• B8.0 cubic yards
• C32.0 cubic yards
• D7.2 cubic yards

A driveway slab is 30 feet by 40 feet by 6 inches. Including a 10 percent waste and subgrade-irregularity allowance, how many cubic yards should be ordered?

• A22.2 cubic yards
• B24.4 cubic yards
• C26.7 cubic yards
• D20.0 cubic yards

A continuous footing is 120 feet long, 20 inches wide, and 10 inches deep. What is the net concrete volume in cubic yards?

• A4.4 cubic yards
• B8.3 cubic yards
• C6.2 cubic yards
• D11.1 cubic yards

A 16-foot-wide slab requires #4 bars spaced 8 inches on center across the 16-foot width (bars run the long direction, including a bar at each edge). How many bars are required in that layer?

• A16 bars
• B25 bars
• C24 bars
• D8 bars

A takeoff requires 18 cubic yards of ready-mixed concrete at USD 165 per cubic yard, delivered. What is the concrete material cost?

• AUSD 2,970
• BUSD 1,650
• CUSD 3,300
• DUSD 2,475

On a typical foundation section, which information is the contractor expected to read for forming and placing a wall?

• AOnly the architectural floor finish schedule
• BOnly the electrical one-line diagram
• COnly the plumbing isometric
• DWall thickness, footing size, reinforcing, and specified cover

A job has a 12-inch-thick wall 27 feet long and 8 feet high, plus a 4-inch slab 27 feet by 18 feet. What is the combined net concrete volume?

• A8.0 cubic yards
• B6.0 cubic yards
• C14.0 cubic yards
• D11.0 cubic yards

Eight cylindrical pier holes are each 18 inches in diameter and 6 feet deep. Including a 5 percent waste allowance, how many cubic yards of concrete should be ordered? Use π = 3.14.

• A3.1 cubic yards
• B3.3 cubic yards
• C4.2 cubic yards
• D2.1 cubic yards

Conventional Portland-cement concrete is a mixture of which four primary ingredients?

• APortland cement, water, fine aggregate, and coarse aggregate
• BLime putty, gypsum plaster, sand, and gravel
• CAsphalt cement, water, sand, and crushed stone
• DEpoxy binder, silica fume only, and two admixtures

The chemical reaction between Portland cement and water that causes concrete to set and gain strength is called:

• ACarbonation
• BEfflorescence
• CHydration
• DCalcination

For a given set of materials, which change most reliably increases compressive strength of properly compacted, well-cured concrete?

• ARaising the water-cementitious materials ratio
• BLowering the water-cementitious materials ratio
• CIncreasing slump by adding water at the site
• DOmitting curing so the surface dries faster

A cubic yard of concrete is batched with 564 pounds of cementitious material and 282 pounds of mixing water (no unaccounted free moisture). What is the water-cementitious materials ratio?

• A0.50
• B0.40
• C0.60
• D2.00

Why is air-entrained concrete specified for exterior West Virginia slabs, walks, and driveways that will be saturated and freeze?

• AEntrapped air voids always increase 28-day compressive strength
• BAir-entraining admixtures replace the need for any curing
• CAir-entrainment is used only to color decorative concrete
• DMicroscopic air voids relieve freezing pressure and improve freeze-thaw durability

Compared with ASTM C150 Type I Portland cement, Type III is selected when the contractor needs:

• ALower heat of hydration for mass pours
• BHigh early strength
• CMaximum sulfate resistance with no other changes
• DA cement that will not hydrate in cold weather

Under ACI 318 durability rules used with IBC 2018, what is the maximum water-cementitious materials ratio for Exposure Class F2 (freezing and thawing in a moist condition, not exposed to deicing chemicals)?

• A0.60
• B0.55
• C0.45
• D0.70

A slump test on fresh concrete is primarily a measure of:

• AConsistency (workability), not a direct measure of compressive strength
• B28-day compressive strength in psi
• CAir content as a percent of volume
• DThe exact water-cementitious materials ratio

After a slab is struck off, which tool is used to embed coarse aggregate slightly and smooth the surface before bleed water appears?

• AA needle (immersion) vibrator dragged across the surface
• BA bull float or darby
• CA power trowel with finish blades
• DA concrete chainsaw

What is the primary purpose of an internal (spud or immersion) vibrator during placement?

• ATo consolidate concrete by removing trapped air and filling the forms around reinforcement
• BTo add mixing water and increase slump
• CTo cut control joints in hardened concrete
• DTo measure air content of the batch

The standard field test for slump of fresh hydraulic-cement concrete uses which apparatus?

• AA 6 × 12 inch cylinder mold filled in two layers and capped
• BA Windsor probe fired into the hardened surface
• CA 12-inch-high truncated cone (slump cone) filled in three layers and rodded, then lifted
• DA rebound hammer struck on the form face

Which placement method is usually selected when concrete must be moved vertically or horizontally beyond practical chute or buggy reach, such as an elevated deck or a tight site?

• AHand shoveling from the street curb only
• BA garden hose used as a tremie
• CA wheelbarrow carried up an unguarded ladder
• DA concrete pump (boom or line) or a crane-and-bucket

What is the primary function of formwork?

• ATo support plastic concrete at the specified shape, alignment, and finish until it can ca…
• BTo replace reinforcing steel in the member
• CTo cure the concrete by chemical reaction with the cement
• DTo measure slump of each truck

Why is a form-release agent applied to reusable form faces before concrete is placed?

• ATo chemically accelerate the set of the entire member
• BTo increase the bond between concrete and the form so stripping is harder
• CTo keep the concrete from bonding to the form so stripping does not damage the surface
• DTo replace the specified concrete cover over reinforcement

What is the purpose of snap ties (or similar form ties) through a wall form?

• ATo serve as the only vertical reinforcement in the wall
• BTo hold opposite form faces at the correct wall thickness against fresh-concrete pressure
• CTo act as electrical conduit sleeves
• DTo replace walers and braces entirely

Kickers and diagonal braces on wall forms are installed primarily to resist:

• AOnly the dead load of empty plywood
• BOnly wind on the finished building roof
• COnly shrinkage of the hardened wall
• DLateral pressure from fresh concrete and to keep the form plumb and in line

All else equal, which placement change increases lateral pressure on a wall form?

• AA faster vertical rate of pour
• BA much stiffer (lower-slump) mix placed slowly
• CCold concrete that sets almost immediately
• DStopping the pour and letting the lower lift set before continuing

Under OSHA 29 CFR 1926.703, drawings or plans for formwork, shoring, working decks, and scaffolds must be:

• AKept only at the contractor's home office and never on site
• BInvented by the placing crew after the first truck arrives
• CAvailable at the jobsite, including all revisions
• DOptional if the pour is less than 50 cubic yards

On a stud-and-sheathing wall form, what do walers (wales) do?

• AThey replace all form ties
• BThey span across studs to distribute tie loads and keep the form face true
• CThey are only decorative battens left in the finished wall
• DThey are used only as scaffold planks

Chamfer strips are placed in inside form corners primarily to:

• AIncrease the structural depth of the member
• BHold reinforcing chairs in mid-depth
• CReplace the specified cover
• DBreak the sharp corner, ease stripping, and reduce edge spalling

OSHA 1926.703 states that adjustment of single-post shores to raise formwork shall:

• ANot be made after the placement of concrete
• BBe made continuously during the pour to keep the slab crowned
• CBe made only after the concrete has reached 28-day strength
• DBe made by unbraced screw jacks under eccentric loads

Except for slabs on grade and slip forms, OSHA requires that forms and shores not be removed until:

• AThe surface is dry to the touch, regardless of strength
• BThe employer determines the concrete has gained sufficient strength to support its weight…
• CExactly 2 hours have passed after finishing
• DThe ready-mix ticket is signed

Which combination produces the highest lateral pressure on a tall wall form?

• ASlow pour, stiff mix, warm weather, no vibration
• BSlow pour in 90°F weather with a 1-inch slump
• CFast pour, high slump, cool weather, and internal vibration
• DPlacing 6-inch lifts and waiting for each lift to reach initial set

When single-post shores are stacked one on top of another (tiered), OSHA requires, among other things, that:

• AThe crew may omit bracing if the posts look plumb
• BAnyone on site may design the stack after concrete is in the forms
• CThe posts may be out of plumb if they are nailed
• DThe shoring design is prepared by a qualified designer and the erected shoring is inspect…

A #4 deformed reinforcing bar has a nominal diameter of:

• A3/8 inch
• B1/2 inch
• C5/8 inch
• D3/4 inch

The principal structural reason deformed steel bars are placed in concrete is to:

• AResist tensile stresses that concrete cannot carry reliably
• BColor the mix for decorative work
• CReplace all coarse aggregate in the mixture
• DEliminate any need for concrete cover

Bar supports (chairs, bolsters, or concrete dobies) are used to:

• AIncrease the specified slump of the mixture
• BSplice bars without a lap
• CHold reinforcement at the specified location and concrete cover during placement
• DCure the slab by sealing the surface

Annealed tie wire is used in reinforced concrete construction to:

• AReplace the specified development length of the bars
• BServe as the primary flexural reinforcement
• CPreheat the bars for welding on every job
• DHold crossing bars in position until the concrete is placed

For cast-in-place nonprestressed concrete cast against and permanently exposed to earth, ACI 318 minimum specified cover to reinforcement is:

• A3 inches
• B2 inches
• C1-1/2 inches
• D3/4 inch

What is the ACI 318 minimum specified cover for a #6 bar in cast-in-place concrete exposed to earth or weather (not cast against the soil)?

• A3 inches
• B2 inches
• C1-1/2 inches
• D1 inch

For a #4 bar in cast-in-place concrete exposed to earth or weather (formed, not cast against soil), ACI 318 minimum specified cover is:

• A3 inches
• B2 inches
• C1-1/2 inches
• D3/4 inch

For #5 bars in a cast-in-place slab that is not exposed to weather and not in contact with the ground, ACI 318 minimum specified cover is:

• A3 inches
• B2 inches
• C1-1/2 inches
• D3/4 inch

A one-way slab is 20 feet wide. Temperature bars run the 20-foot direction and are spaced 12 inches on center, with a bar at each edge. How many of those bars are required?

• A21 bars
• B20 bars
• C12 bars
• D10 bars

ACI 318 minimum clear spacing between parallel bars in a layer is the greatest of:

• A1/4 inch, 1/2 db, and the smallest aggregate size
• B1 inch, the bar diameter db, and (4/3) times the nominal maximum aggregate size
• C6 inches, 3 db, and twice the cover
• D18 inches only, regardless of bar size or aggregate