California CSLB C-8 Concrete Examination

A contractor is estimating concrete for a slab-on-grade measuring 40 feet wide by 60 feet long and 6 inches thick. Factoring in an industry-standard 10% waste allowance, how many cubic yards of concrete must be ordered?

• A48.9 cubic yards of concrete
• B44.4 cubic yards of concrete
• C53.3 cubic yards of concrete
• D40.0 cubic yards of concrete

A continuous perimeter footing measures 250 linear feet in total length, 18 inches wide, and 12 inches deep. Including a 5% waste allowance, what total volume of concrete should be estimated?

• A16.3 cubic yards of concrete
• B14.6 cubic yards of concrete
• C13.9 cubic yards of concrete
• D18.2 cubic yards of concrete

A foundation plan calls for 12 cylindrical caissons, each 24 inches in diameter and 8 feet deep. Adding a 5% waste factor, how many cubic yards of concrete are required?

• A14.8 cubic yards of concrete
• B08.9 cubic yards of concrete
• C11.7 cubic yards of concrete
• D15.4 cubic yards of concrete

A foundation drawing requires 12 continuous runs of #5 rebar in a 200-foot footing. Each run has 4 lap splices requiring 30 inches of overlap. Knowing #5 rebar weighs 1.043 lbs/ft, what is the total estimated rebar weight?

• A2,503 lbs of reinforcement
• B2,784 lbs of reinforcement
• C3,129 lbs of reinforcement
• D2,628 lbs of reinforcement

A concrete mix design contains 564 lbs of Type II Portland cement and 225 lbs of mixing water per cubic yard. What is the calculated water-cement (w/c) ratio of this concrete mix?

• A0.40 water-cement ratio
• B0.45 water-cement ratio
• C0.35 water-cement ratio
• D0.50 water-cement ratio

When estimating formwork for a retaining wall stem measuring 80 feet long by 10 feet high, what is the total Square Feet of Contact Area (SFCA) requiring formwork?

• A0,800 SFCA of formwork
• B1,600 SFCA of formwork
• C2,400 SFCA of formwork
• D3,200 SFCA of formwork

A slab-on-grade requires a grid of #4 rebar spaced at 12 inches on center in both directions over a 50 ft by 50 ft area. Knowing #4 rebar weighs 0.668 lbs/ft, what is the estimated weight of steel excluding laps?

• A1,703 lbs of steel rebar
• B5,100 lbs of steel rebar
• C3,407 lbs of steel rebar
• D2,550 lbs of steel rebar

Per ACI 318-19 and CBC Chapter 19, what is the maximum permitted water-cementitious materials ratio for structural concrete exposed to severe freezing and thawing in a moist condition (Exposure Class F2)?

• A0.50 maximum w/c ratio
• B0.40 maximum w/c ratio
• C0.55 maximum w/c ratio
• D0.45 maximum w/c ratio

According to ACI 347R, what is the estimated maximum lateral pressure on wall forms for concrete placed at a rate of 4 ft/hr at a concrete temperature of 70 degrees Fahrenheit?

• A664 lbs/sq ft pressure
• B850 lbs/sq ft pressure
• C450 lbs/sq ft pressure
• D950 lbs/sq ft pressure

A structural plan specifies #6 reinforcing bars with a required Class B lap splice of 40 bar diameters (40db). What is the minimum lap splice length required?

• A24 inches minimum lap
• B30 inches minimum lap
• C36 inches minimum lap
• D20 inches minimum lap

How many ready-mix concrete truckloads are required to deliver 145 cubic yards of concrete if each transit mixer carries a maximum load of 10 cubic yards?

• A14 truckloads of concrete
• B16 truckloads of concrete
• C15 truckloads of concrete
• D13 truckloads of concrete

A liquid membrane-forming curing compound complying with ASTM C309 is specified for application at a coverage rate of 200 sq ft per gallon. How many gallons are needed for a 12,000 sq ft slab?

• A50 gallons of compound
• B40 gallons of compound
• C80 gallons of compound
• D60 gallons of compound

What does the blueprint callout symbol '12 - #6 @ 10" O.C. E.W.' indicate for slab reinforcement placement?

• ATwelve #6 bars placed at 10 inches on center in each way
• BTwelve #6 bars placed at 10 inches off center on east wall
• CTwelve #6 bars spaced 10 inches apart on exterior wall
• DTwelve #6 bars placed at 10 inches on center in end wall

A project requires pouring 16 isolated spread footings, each measuring 4 feet by 4 feet square and 18 inches thick. Including 5% waste, what total volume of concrete should be ordered?

• A15.0 cubic yards of concrete
• B14.2 cubic yards of concrete
• C13.5 cubic yards of concrete
• D12.8 cubic yards of concrete

A concrete mix requires 5.5 sacks of Portland cement per cubic yard. If each sack weighs 94 lbs, what is the total weight of cement required for a 30 cubic yard pour?

• A12,408 lbs of cement
• B18,612 lbs of cement
• C15,510 lbs of cement
• D13,950 lbs of cement

When estimating vapor retarder rolls for an 80 ft by 100 ft building footprint, allowing 10% extra for roll overlaps and fitting, how many square feet of material must be purchased?

• A08,000 sq ft of retarder
• B09,600 sq ft of retarder
• C10,400 sq ft of retarder
• D08,800 sq ft of retarder

How many linear feet of expansion joint material are needed to isolate a 150 ft by 200 ft rectangular commercial slab from all surrounding exterior foundation walls?

• A700 linear feet of joint
• B350 linear feet of joint
• C500 linear feet of joint
• D600 linear feet of joint

A concrete stem wall is 120 feet long, 8 inches thick, and 4 feet high. What is the net volume of concrete required in cubic yards?

• A14.2 cubic yards of concrete
• B11.9 cubic yards of concrete
• C17.8 cubic yards of concrete
• D15.5 cubic yards of concrete

If #8 reinforcing steel bars weigh 2.67 lbs per linear foot, how many tons of rebar are needed for a job requiring 3,000 linear feet of #8 steel?

• A5.34 tons of rebar steel
• B3.00 tons of rebar steel
• C4.01 tons of rebar steel
• D4.50 tons of rebar steel

A contractor plans to replace 20% of Portland cement with fly ash in a 600 lbs/cu yd mix. How many pounds of fly ash and cement are in each cubic yard?

• A100 lbs fly ash and 500 lbs cement
• B150 lbs fly ash and 450 lbs cement
• C180 lbs fly ash and 420 lbs cement
• D120 lbs fly ash and 480 lbs cement

What is the primary factor influencing the design lateral concrete pressure exerted on vertical formwork according to ACI 347R?

• ARate of placement and temperature
• BAggregate size and sand percentage
• CSlump and water addition at jobsite
• DRebar density and chair clearance

A concrete pump operates at a peak continuous rate of 45 cubic yards per hour. How long will it take to place a 180 cubic yard parking deck slab?

• A3.5 hours of continuous pumping
• B4.0 hours of continuous pumping
• C5.0 hours of continuous pumping
• D4.5 hours of continuous pumping

When estimating lumber board feet for footing forms, how many board feet of 2x6 form boards are required for 200 linear feet of double-sided forms?

• A300 board feet of lumber
• B200 board feet of lumber
• C400 board feet of lumber
• D500 board feet of lumber

A ready-mix truck arrives with 9 cubic yards of concrete. The slump is tested at 2 inches, but the specs call for 4 inches. Approximately how much water can be added to raise the slump by 2 inches?

• A4.5 to 9.0 gallons total water
• B1.0 to 2.0 gallons total water
• C20.0 to 30.0 gallons total water
• D9.0 to 18.0 gallons total water

A structural slab plan specifies Grade 60 rebar. What does the designation 'Grade 60' indicate regarding the mechanical properties of the steel?

• AMinimum yield strength of 60,000 psi
• BMinimum ultimate tensile of 60,000 psi
• CMinimum shear strength of 60,000 psi
• DMinimum compressive limit of 60,000 psi

What is the volume of concrete required for 8 grade beams measuring 20 feet long, 12 inches wide, and 24 inches deep?

• A09.5 cubic yards of concrete
• B11.9 cubic yards of concrete
• C04.7 cubic yards of concrete
• D14.2 cubic yards of concrete

A structural draw legend calls out 'S.S.D. Subgrade' prior to slab placement. What does 'S.S.D.' stand for in concrete site preparation?

• AStandard Soil Density condition
• BSoil Surface Drainage condition
• CSaturated Surface-Dry condition
• DSubgrade Sloping Direction state

How many 94-lb sacks of Portland cement are contained in a standard 6-sack concrete mix order delivering 8 cubic yards?

• A36 sacks of Portland cement
• B42 sacks of Portland cement
• C54 sacks of Portland cement
• D48 sacks of Portland cement

Per ACI 302.1R, what is the primary purpose of pre-wetting an absorbent subgrade to a saturated surface-dry (SSD) condition before placing concrete?

• ATo prevent subgrade absorbing mix water
• BTo lubricate the subgrade for slab sliding
• CTo wash fine sand particles out of base
• DTo cool the ambient air above the slab

According to ACI 302.2R and ASTM E1745, what minimum thickness vapor retarder membrane is recommended beneath interior slabs receiving moisture-sensitive floor coverings?

• A06-mil polyethylene sheet
• B15-mil Class A vapor barrier
• C10-mil Class A vapor barrier
• D04-mil construction sheeting

Per CBC Chapter 19 and ACI 318, what is the minimum concrete cover clearance required for reinforcing steel cast permanently against and exposed to earth?

• A2.0 inches of concrete cover
• B1.5 inches of concrete cover
• C3.0 inches of concrete cover
• D4.0 inches of concrete cover

What is the minimum concrete protective cover required for #5 rebar cast in formed members that will be permanently exposed to weather after form removal?

• A1.0 inch clear cover
• B2.0 inches clear cover
• C2.5 inches clear cover
• D1.5 inches clear cover

Before applying form release agent to plywood wall forms, what precautionary measure must be taken on the jobsite?

• AApply release agent before rebar placement
• BApply release agent after rebar placement too
• CSpray release agent directly onto rebar
• DMix release agent into subgrade gravel

What device is used to maintain correct elevation and clearance of bottom rebar mats above a vapor retarder in slab-on-grade construction?

• AWooden blocks with wire ties
• BPlastic chairs with flat bases
• CMetal stakes driven through film
• DSmooth gravel mounds under bars

What type of joint is installed in a concrete slab to allow independent horizontal and vertical movement relative to adjoining structural columns or walls?

• AContraction control joint
• BConstruction bulkhead joint
• CIsolation expansion joint
• DMonolithic keyway joint

According to ACI 302.1R, contraction (control) joints in a 6-inch thick interior slab should be spaced at what maximum distance?

• A24 to 30 feet apart
• B18 to 20 feet apart
• C06 to 08 feet apart
• D12 to 15 feet apart

What is the primary function of installing smooth, lubricated dowel bars across an expansion joint in a heavy-duty industrial floor slab?

• ATo transfer load while allowing movement
• BTo prevent horizontal slab movement
• CTo tie adjacent slab panels together
• DTo eliminate the need for joint sealant only

Per ACI 301, what standard wire gauge and material is typically specified for tying intersecting rebar in field reinforcement mats?

• A12-gauge galvanized steel wire
• B16-gauge black annealed wire
• C18-gauge aluminum tie wire
• D10-gauge high-tensile wire

What subgrade elevation tolerance is permitted by ACI 302.1R for a slab-on-grade prior to placing granular subbase material?

• A+1/2 inch to -1/2 inch tolerance
• B+1 inch to -1 inch tolerance
• C+0 inch to -1/2 inch tolerance
• D+1/4 inch to -1/4 inch tolerance

What essential component must be installed in wall-to-footing construction joints when waterproofing or groundwater head pressure resistance is specified?

• ASmooth steel dowel sleeve
• BPoured asphalt expansion strip
• CExpanded polystyrene joint board
• DContinuous PVC waterstop strip

Per CBC Chapter 19, foundation anchor bolts supporting wood sill plates must be embedded into solid concrete a minimum depth of how many inches?

• A07 inches minimum embedment
• B05 inches minimum embedment
• C06 inches minimum embedment
• D10 inches minimum embedment

Why is it necessary to pre-wet wood formwork immediately prior to placing fresh concrete into vertical wall forms?

• ATo expand wood forms against snap ties
• BTo prevent wood absorbing batch water
• CTo wash form release oil into subgrade
• DTo lower internal formwork temperature

What is the purpose of placing clean, crushed capillary break rock beneath a concrete floor slab per California Green Building Standards (CALGreen)?

• ATo provide high thermal insulation value
• BTo increase subgrade compaction density
• CTo break soil moisture capillary rise
• DTo replace the need for steel reinforcement