South Carolina Bridges Contractor Examination

Under the SCDOT 2007 Standard Specifications, what is the minimum 28-day compressive strength used to designate Class 4000 structural concrete?

• A4,000 psi
• B5,000 psi
• C6,000 psi
• D3,000 psi

Per SCDOT 701.2.5, air-entrained concrete is required in which of the following bridge elements regardless of the concrete class?

• AOnly lean concrete used as a mud mat
• BOnly mass footings below the water table
• COnly prestressed girders fabricated off-site
• DBridge columns, bent or pier caps, decks, sidewalks, parapets, and barrier walls

For most SCDOT air-entrained structural concrete that is not prestressed, the design mix is based on what target entrained-air content?

• A4.5 percent plus or minus 1.5 percent
• B8.0 percent plus or minus 2.0 percent
• C12 percent with no tolerance
• D2.0 percent plus or minus 0.5 percent

How many cubic feet are in one cubic yard of concrete?

• A36 cubic feet
• B9 cubic feet
• C12 cubic feet
• D27 cubic feet

What is the SCDOT maximum slump for concrete placed in a bridge deck?

• A6 inches
• B9 inches
• C12 inches
• D3 inches

According to OSHA 29 CFR 1926.701, which statement about concrete buckets is correct?

• ANo employee shall be permitted to ride concrete buckets
• BOnly the pump operator may ride the bucket to the deck
• CRiding is allowed below 6 feet of lift height
• DEmployees may ride a concrete bucket if a personal fall-arrest system is used

What is the primary reason air-entraining admixtures are used in South Carolina bridge concrete?

• ATo provide a system of microscopic voids that relieve freeze-thaw pressure in the paste
• BTo replace the need for wet curing on decks
• CTo allow unlimited addition of mix water at the jobsite
• DTo increase 28-day compressive strength above the mix-design value

For SCDOT Class 4000 concrete made with crushed stone, what is the minimum cement content in the structural concrete table?

• A750 lb per cubic yard
• B494 lb per cubic yard
• C588 lb per cubic yard
• D611 lb per cubic yard

What is the SCDOT maximum water-to-cementitious-material ratio for Class 4000 concrete with crushed stone or gravel?

• A0.40
• B0.50
• C0.60
• D0.32

A bridge deck is 80 feet long, 28 feet wide, and 8 inches thick. What is the neat-line concrete volume?

• A55.3 cubic yards
• B83.0 cubic yards
• C166 cubic yards
• D41.5 cubic yards

Under SCDOT 702.4.4, how long must a cast-in-place bridge deck be wet-cured with curing blankets?

• A28 days
• B24 hours
• C4 days
• D7 days

How long does SCDOT 702.4.4.2 require wet-curing of structural concrete other than bridge decks?

• A14 days
• B12 hours
• C2 days
• D4 days

SCDOT’s evaporation nomograph (Figure A-7) warns that precautions against plastic-shrinkage cracking are necessary when the evaporation rate approaches which value?

• A0.2 lb/ft²/hr
• B2.0 lb/ft²/hr
• C20 lb/ft²/hr
• D0.02 lb/ft²/hr

If SCDOT structural concrete is pumped, at what air content measured at the truck is the entrained air considered acceptable?

• A9.0 percent with no tolerance
• B2.5 percent plus or minus 1.5 percent
• C4.5 percent plus or minus 0.5 percent
• D5.5 percent plus or minus 1.5 percent

Calcium chloride accelerating admixtures are generally not recommended for which application?

• APrestressed concrete, because of the corrosion hazard to prestressing steel
• BPlain concrete mud mats
• CTemporary barrier that will be discarded
• DNon-reinforced sidewalks in cool weather

ACI cold-weather concreting practice, which the Contractor’s Guide follows, treats concreting as cold-weather work when the mean daily temperature is at or expected to fall below what value?

• A55°F
• B20°F
• C32°F
• D40°F

When consolidating structural concrete with an internal vibrator, which practice is correct?

• AInsert the vibrator vertically, let it sink under its own weight, and withdraw it slowly
• BVibrate in one spot until a thick layer of paste and water stands on the surface
• CRest the vibrator against the nearest rebar so the steel transmits the vibration
• DUse the vibrator to drag concrete horizontally along the forms

Which SCDOT placements are allowed a maximum slump of 9 inches (with approved water-reducing admixtures) rather than the 6-inch deck limit?

• ASeal concrete, drilled-shaft concrete, and prestressed concrete
• BParapets finished by hand trowel only
• CAny Class 3000 concrete, regardless of element
• DBridge decks and approach slabs only

A pier cap measures 26 feet long, 4 feet wide, and 3.5 feet deep. How many cubic yards of concrete are required (neat line, no waste)?

• A13.5 cubic yards
• B27.0 cubic yards
• C364 cubic yards
• D3.5 cubic yards

A contractor will place 48.0 neat-line cubic yards of Class 4000 deck concrete and must add 8 percent for waste, overrun, and grade irregularities. How many cubic yards should be ordered?

• A56.0 cubic yards
• B48.0 cubic yards
• C51.8 cubic yards
• D52.0 cubic yards

When SCDOT stay-in-place (SIP) steel forms are used for a concrete deck, what minimum concrete cover is required over the bottom mat of reinforcing steel in the SIP forms?

• A1 inch
• B2-1/2 inches
• C3 inches
• D1/2 inch

Unless specified and approved on the shop plans, SCDOT prohibits welding stay-in-place deck forms to which of the following?

• ABeam or girder flanges or other structural steel bridge elements
• BThe temporary wooden bulkhead at a construction joint
• CThe contractor’s lifting lugs on the form bundles in the yard
• DAdjacent SIP form laps only

If SCDOT acceptance cylinders show that placed structural concrete has not reached the specified 28-day design strength, the specifications direct particular attention when the result is below what percentage of the specified strength?

• A110 percent
• B50 percent
• C70 percent
• D90 percent

Using a conventional normalweight concrete unit weight of 150 lb/ft³, what is the weight of 12.0 cubic yards of concrete?

• A48.6 tons
• B1,800 lb
• C4,050 lb
• D24.3 tons

SCDOT Section 703, as amended, requires reinforcing bars to meet AASHTO M 31, Type W, at what minimum yield strength designation?

• AGrade 80 (80,000 psi)
• BGrade 40 (40,000 psi)
• CGrade 50 (50,000 psi)
• DGrade 60 (60,000 psi)

What is the nominal diameter of a #8 reinforcing bar?

• A1/2 inch
• B5/8 inch
• C3/4 inch
• D1 inch

OSHA 1926.701(b) requires which protection for protruding reinforcing steel onto or into which employees could fall?

• AGuard the steel to eliminate the hazard of impalement
• BBend every bar to a 90-degree hook, regardless of the design
• CCover only vertical column dowels that are more than 10 feet tall
• DPaint the bar ends orange so they are visible

Each shipment of reinforcing steel delivered to an SCDOT project must be accompanied by which document for each heat?

• AThe manufacturer’s mill test report for each heat included in the delivery
• BA contractor-prepared bar-bending schedule with no mill data
• CA paint-color chart for epoxy-coated bars
• DA truck bill of lading listing only the total weight

Using the standard weight of 1.043 lb/ft for #5 bar, what is the total weight of 180 pieces of #5 bar, each 20 feet long?

• A3,755 lb
• B4,172 lb
• C7,510 lb
• D1,880 lb

What is the nominal diameter of a #4 reinforcing bar?

• A3/4 inch
• B1/4 inch
• C3/8 inch
• D1/2 inch

The SCDOT amendment to Subsection 703.2.1 replaced ASTM A 706 with which specification for reinforcing bars?

• AAASHTO M 31, Type W
• BASTM A 325
• CAASHTO M 270, Grade 50
• DASTM A 36

Using 2.670 lb/ft for #8 bar, what is the weight of 36 bars, each 30 feet long?

• A2,884 lb
• B3,204 lb
• C4,806 lb
• D1,442 lb

A bent cap takeoff includes 240 lin ft of #8 main bars (2.670 lb/ft) and 360 lin ft of #5 stirrups (1.043 lb/ft). What is the total rebar weight?

• A1,016 lb
• B1,380 lb
• C2,032 lb
• D641 lb

On federal-aid SCDOT projects, Section 703.1.2 addresses production of iron and steel products. What is the contractor’s basic obligation for reinforcing steel, tie wire, supports, and coatings?

• AUse only iron and steel products that comply with the federal domestic-content (Buy Ameri…
• BDomestic content applies only to structural steel girders, never to rebar
• CCoatings and tie wire are exempt from iron-and-steel rules
• DAny imported bar may be used if it is Grade 60

OSHA 1926.703(a)(1) requires formwork to be designed, fabricated, erected, supported, braced, and maintained so that it can support which loads without failure?

• AAll vertical and lateral loads that may reasonably be anticipated
• BWind load only, because concrete is placed slowly
• CA uniform 20 psf construction live load and nothing else
• DOnly the dead weight of the empty forms

When must shoring equipment be inspected under OSHA 1926.703?

• AOnce per year by the crane manufacturer
• BOnly if the pour will exceed 100 cubic yards
• COnly after a formwork failure
• DPrior to erection, to confirm it meets the formwork drawings

OSHA 1926.703 requires drawings or plans for formwork, shoring, and reshoring to be available where?

• AOnly with the ready-mix producer
• BOnly inside the sealed PE calculation packet that never leaves the designer’s office
• COnly in the contractor’s home-office file after the project is complete
• DAt the jobsite

OSHA 1926.703(e) allows formwork and shores to be removed only when which condition is met?

• AFour hours have elapsed since the last truck left
• BThe weather forecast shows no rain for 24 hours
• CThe surface is dry to the touch
• DThe employer determines that the concrete has gained sufficient strength to support its w…

OSHA 1926.703(d) requires reinforcing steel for walls, piers, columns, and similar vertical structures to be which of the following?

• AWelded to the forms at every tie location
• BInstalled only after the concrete reaches 75 percent strength
• CLeft free-standing so it can be plumbed during the pour
• DAdequately supported to prevent overturning and collapse

Under OSHA 1926.501, each employee on the face of formwork or reinforcing steel shall be protected from falling how far or more to a lower level?

• A15 feet
• B30 feet
• C4 feet
• D6 feet

Under OSHA 1926.704, lifting hardware used to handle precast concrete members must be capable of supporting at least how many times the maximum intended load?

• ATwo times
• BFour times
• CFive times
• DTen times

For vertical slip forms, OSHA 1926.703(c) requires jacks and vertical supports to be provided with which of the following?

• AA single manual pin shared by all jacks
• BNo holding device if the pour rate is less than 6 inches per hour
• CWooden wedges instead of a holding device
• DAutomatic holding devices so the form cannot drop if a jack fails

OSHA 1926.755 requires every column to be anchored by a minimum of how many anchor rods (anchor bolts)?

• ATwo
• BThree
• CFour
• DSix

Except for connectors and controlled decking zones, OSHA 1926.760 requires fall protection for steel-erection employees on unprotected sides more than how far above a lower level?

• A4 feet
• B6 feet
• C15 feet
• D30 feet