Florida Certified Structural Pre-Stress and Precast Specialty Contractor Exam

What is the fundamental difference between pre-tensioned and post-tensioned prestressed concrete?

• APre-tensioned strands are stressed before concrete is cast; post-tensioned tendons are st…
• BPre-tensioned strands are stressed after the concrete cures; post-tensioned tendons are s…
• CBoth methods stress the steel after the concrete has hardened, but only post-tensioning u…
• DPre-tensioning uses ducts and grease, while post-tensioning uses bond transfer only.

Prestressing strand used in precast prestressed concrete members is most commonly which of the following?

• A7-wire, low-relaxation steel strand with a nominal diameter of 1/2 inch and an ultimate s…
• BSolid round mild steel bar with a yield strength of 60 ksi
• CHigh-strength stainless steel cable with a 150 ksi ultimate
• DGalvanized welded wire rope used for guardrails

In structural precast construction, what does the term 'precast' indicate about a concrete member?

• AIt is cast and cured at a location other than its final position, then transported and er…
• BIt is cast in its final position within the structure using permanent formwork.
• CIt is cast only from pre-blended bagged concrete mixes.
• DIt is cast on site the same day it is erected, with no transport.

Why is prestressing force applied to a concrete member before it carries service loads?

• ATo induce a pre-compression that offsets the tensile stresses caused by service loads, ke…
• BTo increase the concrete's compressive strength beyond its 28-day design value.
• CTo bond the reinforcing steel to the concrete without using ties or chairs.
• DTo reduce the member's dead weight so smaller cranes can lift it.

When pre-tensioned strands are released (detensioned), the concrete must have reached a minimum strength called the transfer strength. This is typically what percentage of the specified 28-day compressive strength?

• AApproximately 70 to 80 percent of the specified 28-day strength
• BExactly 50 percent of the 28-day strength
• C100 percent of the 28-day strength is always required before release
• DThere is no minimum; strands can be released at any age

In a pre-tensioned member, how is the prestressing force transferred from the strand to the concrete?

• ABy bond between the strand and the concrete when the strands are cut and released
• BBy mechanical anchorages cast into the ends of the member
• CBy post-tensioning wedges seated in bearing plates
• DBy welding the strand to embedded plates

A 1/2-inch diameter, 270 ksi prestressing strand has a nominal cross-sectional area of 0.153 sq in. If a single strand is jacked to 70% of its ultimate strength, what is the approximate jacking force?

• AApproximately 28.9 kips
• BApproximately 41.3 kips
• CApproximately 13.8 kips
• DApproximately 70.0 kips

On a precast erection project, which drawing shows the location, orientation, and mark number of each piece as it is to be placed in the structure?

• AThe erection drawings
• BThe reinforcing shop drawings
• CThe concrete mix design submittal
• DThe site grading plan

What is the primary purpose of precast shop drawings prepared by the fabricator?

• ATo detail how each member is manufactured: dimensions, reinforcement, strand layout, embe…
• BTo show where each finished piece is placed in the finished building
• CTo record the daily concrete cylinder breaks at the plant
• DTo bill the owner for delivered material

On a precast project, which of the following is considered a 'construction document' that defines the scope and contractual requirements for the work?

• AThe contract drawings and project specifications
• BThe erector's daily lift log
• CThe crane operator's certification card
• DThe ready-mix truck tickets

Which of the following pieces of information must appear on a precast erection drawing for the erector to set a member correctly?

• APiece mark, piece weight, and the location/elevation where the piece is to be set
• BOnly the piece mark; everything else is left to the crane operator
• CThe concrete supplier's phone number and the mix design number
• DThe general contractor's license number

Tolerances for precast and prestressed concrete members (dimensions, squareness, sweep, and camber) are published in which PCI manual?

• APCI MNL-135, Manual for Quality Control for Plants and Production of Structural Precast C…
• BPCI MNL-116, Manual for the Design of Structural Prestressed Concrete
• CACI 318, Building Code Requirements for Structural Concrete
• DOSHA 29 CFR 1926 Subpart CC

When a prestressed member is designed, the engineer accounts for prestress losses. Which of the following is a recognized component of prestress loss?

• AElastic shortening of the concrete, creep, shrinkage, and relaxation of the strand
• BOnly the weight of the crane used to lift the member
• CWind load on the building during construction
• DThe cost of the stressing jacks

Bearing length and seat width for a precast member resting on a beam or wall must account for which combination of effects?

• ABearing stress on the support, tolerance in piece length and setting, and the required st…
• BOnly the color of the finished concrete
• CThe number of workers on the crew that will set the piece
• DThe brand of the crane manufacturer

On a set of precast erection drawings, what does the erection sequence indicate to the field crew?

• AThe order in which members are to be set so each piece is supported and connections can p…
• BThe order in which to mix the concrete batches
• CThe order in which to pay subcontractors
• DThe order in which to paint the finished structure

What is the purpose of the 'piece marking' system shown on precast shop and erection drawings?

• ATo give each unique member a unique identifier that ties the shop drawing, the production…
• BTo brand the precaster's logo onto the concrete
• CTo color-code pieces by the crew that will install them
• DTo list the price of each piece

Precast drawings typically list a camber value for prestressed members. Why must the erector and the designer account for this camber?

• ACamber affects the elevation of the top of the member after setting and the fit of adjoin…
• BCamber is only an aesthetic feature and has no structural meaning
• CCamber is removed by grinding the member flat before erection
• DCamber indicates the member is defective and must be rejected

Which of the following connection types is commonly detailed on precast erection drawings to tie a floor member to its support?

• AWelded plates, grouted sleeves, and mechanical anchors with their size, location, and wel…
• BPost-installed adhesive anchors chosen by the erector in the field to suit the actual gap
• CFriction developed by the bearing pad, which is sized to transfer the required lateral fo…
• DA cast-in-place topping alone, with no hardware at the bearing

When the precast designer specifies a 'bearing seat length' on the erection drawings, what does that dimension control?

• AThe minimum length of bearing the member must actually rest on after all setting and fabr…
• BThe length of the crane boom needed to set the member
• CThe length of the trailer used to haul the member
• DThe length of the weld on a connection plate

In a precast structure, the connection between a precast double-tee floor and its supporting beam must do more than carry gravity. What additional role does the connection detail provide?

• AIt ties the diaphragm, transfers lateral loads to the frame, and accommodates the dimensi…
• BIt only holds the piece from falling off during the lift
• CIt seals the joint against water only
• DIt provides architectural shadow lines only

When precast is connected to a cast-in-place concrete frame, why must the designer coordinate tolerances between the two systems carefully?

• APrecast is held to tight plant tolerances while cast-in-place is looser, and the connecti…
• BCast-in-place is always more accurate than precast
• CThe two systems never connect, so coordination is unnecessary
• DTolerances are the same for both systems by code

In a pre-tensioning plant, what is the long-line casting bed used for?

• ATo tension strands along an extended bed so multiple members can be cast end-to-end in on…
• BTo cure concrete members in cold weather using heated beds
• CTo store finished product before shipping
• DTo mix the concrete batches before placing

Why are form-release agents applied to precast molds and forms before placing concrete?

• ATo prevent the concrete from sticking to the form and to give a clean, stain-free surface…
• BTo increase the compressive strength of the cast concrete
• CTo color the finished concrete a uniform gray
• DTo retard the set of the concrete so it stays workable longer

What is the purpose of maintaining a specified concrete cover over reinforcing steel and prestressing strand in a member?

• ATo protect the steel from corrosion and to develop bond and fire resistance
• BTo make the member lighter by reducing the concrete section
• CTo increase the camber of the member
• DTo reduce the amount of strand required

When detensioning pre-tensioned strands on a long-line bed, what practice helps avoid sudden force transfer that can crack the members?

• ARelease the strands slowly and symmetrically from both ends, or use flame-cut sequences t…
• BCut all strands on one end at once with an abrasive saw as fast as possible
• CDetension only after the concrete reaches 28-day strength
• DDetension by pulling the strands tighter before cutting

Precast and prestressed concrete mixes typically use a low water-cement ratio with high-early-strength cement and admixtures. What is the main production reason?

• ATo reach transfer strength early (often overnight) so the bed can be recycled each day
• BTo make the concrete flowable enough to pump without vibration
• CTo produce a darker gray color
• DTo reduce the cost of cement by using less of it

On a pre-tensioning bed, strands are tensioned to a specified jacking force. Why is that force usually taken beyond the final design prestress (an 'overstress' at jacking)?

• ATo account for the losses (elastic shortening, creep, shrinkage, relaxation) that occur a…
• BTo make the strands easier to cut later
• CTo reduce the required concrete strength at transfer
• DTo allow using fewer strands in the member

A pre-tensioned beam uses four 1/2-inch-diameter 270 ksi low-relaxation strands (area 0.153 sq in each), each stressed to an effective prestress of 0.60 fpu after losses. What is the approximate total effective prestress force in the member?

• AApproximately 99 kips
• BApproximately 165 kips
• CApproximately 33 kips
• DApproximately 270 kips

On a pre-tensioning bed, how is the spacing and profile of the strands controlled?

• ABy strand templates (bulkheads) and hold-down devices placed per the strand profile shown…
• BBy the crane operator eyeballing the layout
• CStrand spacing is not controlled; any arrangement is acceptable
• DStrands are placed only after the concrete is poured

In a pre-tensioning plant, what resists the large longitudinal force in the stressed strands before the concrete is cast?

• AThe stressing abutments and the bed frame, which are designed to carry the full jacking f…
• BThe fresh concrete, once it is placed
• CThe rebar in the member
• DThe forms themselves

Accelerated curing (steam or low-pressure heat) is commonly used in precast plants. What is its primary purpose in production?

• ATo reach the concrete transfer strength quickly so the bed can be stripped and reused the…
• BTo color the concrete a consistent shade
• CTo dry the concrete so it does not need finishing
• DTo prevent the concrete from ever curing

What is used in the form to keep reinforcing bars and prestressing strand at the correct cover distance from the form face?

• ABar chairs, spacers, and side-form spacers sized to the required cover
• BTie wire wrapped at each bar intersection, which holds the cage at the design cover
• CThe strand jacking force, which lifts the reinforcement off the form face during tensioni…
• DVibration during casting, which floats the steel up to its design position

A precast beam is 24 inches wide and 20 inches deep and 40 feet long. Using concrete weighing 150 lb per cubic foot, what is the approximate weight of the beam?

• AApproximately 20,000 lb
• BApproximately 2,400 lb
• CApproximately 4,800 lb
• DApproximately 480 lb

When placing concrete in a precast form, why is internal vibration used?

• ATo consolidate the concrete around the rebar and strand and eliminate voids and honeycomb…
• BTo make the concrete change color
• CTo add water to the mix on site
• DTo speed up curing without any heat input

What is the purpose of finishing (screeding/troweling) the top surface of a precast member after placement?

• ATo bring the top surface to the specified elevation, smoothness, and finish shown on the…
• BTo add color to the concrete
• CTo reduce the member's weight
• DTo replace the need for curing

When a precast member is too long or too wide for a standard truck trailer, what is typically required before it can be hauled on public roads?

• AAn oversize/overweight permit and, depending on dimensions, escort vehicles and a specifi…
• BWarning flags and lights on the overhanging end, which are what authorize an over-length…
• CA certified weight ticket from the plant scale, which satisfies the state limit if axle l…
• DWritten approval from the engineer of record, who signs the shipping drawing to authorize…

Before the first precast lift of the day, the crew holds a pre-lift (toolbox) meeting. What is its main purpose?

• ATo review the lift plan, the piece weight, the crane capacity, the signal person, and the…
• BTo assign lunch breaks for the day
• CTo collect personal phone numbers
• DTo pick the color of the next piece

When a precast member is set, why are shims used at the bearing?

• ATo adjust the piece to the correct elevation and to level it before the connection is mad…
• BTo permanently hold the piece in place without any connection
• CTo color the joint
• DTo add weight to the member

On a precast erection site, the crane operator must follow signals from one designated signal person. Which standard governs the hand signals used for mobile crane operations?

• AASME B30.5 (and OSHA 1926 Subpart CC) standard hand signals for cranes
• BThe precaster's own custom hand signals
• CAny gestures the crew invents that day
• DThere is no standard; signals are optional

What is the function of a bearing pad placed between a precast member and its support?

• ATo distribute the reaction over a larger area, accommodate small rotations, and prevent s…
• BTo glue the member permanently to the support so it cannot move
• CTo add color contrast between the member and the support
• DTo replace the need for any mechanical connection

Before each precast lift, what should be inspected on the rigging hardware (shackles, slings, hooks)?

• ACheck for cracks, deformation, worn pins, missing latches, and legible tags with rated ca…
• BOnly that the sling's rated capacity exceeds the member weight, since in-service slings a…
• COnly that a competent person documented an inspection within the last twelve months
• DOnly that the crane's load chart covers the pick, since the chart governs the whole riggi…

Why is a spreader bar used when lifting long or wide precast members?

• ATo keep the sling legs apart so they do not crush the member and so the sling angle stays…
• BTo add weight to the lift
• CTo change the color of the sling
• DTo replace the crane hook

What action should be taken if wind speeds rise above the limit set by the crane manufacturer or the lift plan during a precast pick?

• AStop the lift, lower the load if it is safe to do so, and wait until wind is within limits
• BContinue the pick but add a second tag line to control the member against the wind
• CContinue the pick but reduce the working radius to regain the capacity lost to wind
• DContinue the pick as long as the load moment indicator is not showing an overload

When a mobile crane is set up to lift precast members, what must the outriggers or crawlers rest on?

• AStable cribbing/mats or prepared ground capable of supporting the crane's maximum bearing…
• BAny subgrade that has already passed the building pad's compaction test
• CThe structural slab on grade, which is designed to carry the building's live load
• DTimber blocking sized to match the dimensions of the outrigger float itself

Before setting precast columns or wall panels, what does the crew lay out on the structure to ensure pieces are placed in the correct location?

• ASurvey control lines (column lines, offset lines) and elevation benchmarks
• BThe erection drawings alone, since each piece mark fits only one opening in the frame
• CThe anchor bolts and embed plates already cast into the supporting structure
• DA laser level set to the finished floor elevation, which fixes plan location and height t…