Alabama Concrete Pavement Contractor Examination

When installing gravity sanitary sewer pipe, what is the primary purpose of maintaining a constant, designed slope between manholes?

• ATo maximize pipe wall thickness
• BTo ensure self-cleansing velocity and proper drainage flow
• CTo reduce the need for bedding material
• DTo allow the pipe to float in saturated soils

For flexible PVC water main, which bedding practice best protects the pipe and maintains long-term ovality control?

• ALay the pipe directly on undisturbed rock ledge with no cushion
• BProvide uniform, compacted granular bedding and haunching to the springline
• CBackfill only over the crown and leave the invert unsupported
• DUse large cobbles under the invert for drainage

What is the standard function of a water main thrust block at a bend or tee?

• ATo reduce pipe wall thickness requirements
• BTo transfer unbalanced hydrostatic thrust into undisturbed soil
• CTo serve as a permanent shutoff valve
• DTo replace restrained joints on all pipelines

Before a newly installed potable water main is placed in service, which sequence is typically required?

• APressure test only; flush once and open to customers
• BFlush, pressure (hydrostatic) test, disinfect, and obtain satisfactory bacteriological re…
• CDisinfect first, then pressure test with untreated trench water
• DVisual inspection only if the pipe is NSF-listed

What is the purpose of a manhole invert channel in a sanitary sewer system?

• ATo store grit until vacuum trucks arrive
• BTo guide flow smoothly through the manhole and reduce turbulence and solids deposition
• CTo provide a dry work platform above the flow line
• DTo replace the need for upstream cleanouts

When crossing under an existing concrete pavement with a new water service, which method most reduces risk of undermining the slab?

• AOpen-cut a full-width trench through the pavement without shoring
• BBore or jack the service in a casing with controlled grade, then restore pavement only wh…
• CFlood the trench to float the pipe under the slab
• DRemove every other pavement panel regardless of alignment

What is the main reason sewer pipe joints must be properly lubricated and fully home during assembly of gasketed push-on joints?

• ATo increase the pipe’s pressure rating above design
• BTo seat the gasket and create a soil- and water-tight seal without rolling or pinching th…
• CTo eliminate the need for bedding
• DTo allow the line to be laid on reverse grade

For trench excavation deeper than 5 feet in Type C soil with no sloping or benching, what OSHA-required protection is generally needed for workers in the trench?

• ANone if the trench is less than 100 feet long
• BA protective system such as shoring, shielding (trench box), or other engineered protecti…
• COnly a hard hat and safety glasses
• DA single wooden plank across the trench top

Why is select granular backfill often required in the pipe zone under future concrete pavement?

• ATo chemically bond the pipe to the pavement slab
• BTo provide uniform support, drainage, and controlled compaction that limits differential…
• CTo eliminate the need for base course under the pavement
• DTo increase the pipe’s internal diameter

What is the primary purpose of a sewer force main air release valve at high points?

• ATo add chlorine to the wastewater
• BTo release trapped air that can restrict flow and cause surges
• CTo convert the force main to gravity flow
• DTo measure pipe ovality

When connecting a new sewer lateral to an existing main, which practice is generally preferred?

• ABreak a rough hole with a hammer and mortar a stub loosely in place
• BUse an approved saddle, wye, or manufactured fitting with a watertight joint per specific…
• CInsert the lateral without a gasket if the hole looks tight
• DAlways core through the crown and leave the connection unsealed for drainage

What does a low-pressure air test on a newly installed gravity sewer primarily verify?

• ACompressive strength of the pipe wall
• BJoint and pipe integrity against leakage (infiltration/exfiltration path)
• CExact flow capacity in gallons per minute
• DChemical resistance of the gasket

Minimum cover over a water main under a roadway is typically governed by which consideration?

• AOnly the color of the pipe
• BFreeze depth, traffic loading, and owner/specification minimum depth requirements
• CThe diameter of nearby sewer only
• DWhether the trench is wet or dry on the day of installation

Horizontal separation between potable water mains and sanitary sewers is required primarily to:

• AReduce pipe purchase cost
• BLimit contamination of the water main if the sewer leaks
• CAllow both lines to share the same trench bedding without restriction
• DEliminate the need for valves

During dewatering of a deep utility trench beside an existing concrete pavement, what is a major risk if groundwater is lowered too aggressively without control?

• AIncreased compressive strength of the pavement concrete
• BLoss of fine soils, settlement, and cracking of adjacent pavement and utilities
• CAutomatic improvement of subgrade CBR
• DElimination of all trench wall support needs

What is the purpose of a cleanout on a building sewer or small diameter collection line?

• ATo increase pipe pressure rating
• BTo provide access for cleaning, inspection, and rodding without excavating the entire run
• CTo serve as the only manhole on a large interceptor
• DTo meter wastewater flow continuously

Before excavating for a gas service line, what is the first safety-critical administrative step?

• AStart digging carefully with a backhoe on low throttle
• BNotify the one-call system (811) and wait for utility marks and clearance
• CAssume plastic gas lines are always deeper than 6 feet
• DFlood the area to locate bubbles over the line

Under the APWA uniform color code, what color marking indicates gas, oil, steam, petroleum, or other gaseous materials?

• ABlue
• BYellow
• CGreen
• DOrange

When working within the tolerance zone of a marked gas line, which excavation practice is required?

• AFull-power bucket digging directly on the marks to save time
• BHand dig, vacuum excavate, or use other non-destructive methods until the facility is exp…
• CIgnore marks if the line is plastic
• DUse explosives for precise exposure

What is the primary purpose of tracer wire installed with plastic gas piping?

• ATo strengthen the pipe against internal pressure
• BTo allow electronic location of the non-metallic line after burial
• CTo serve as a grounding electrode for lightning
• DTo heat the gas during winter

If a gas odor is detected during excavation near a marked or unmarked line, what should crews do first?

• AContinue digging to find the leak source with the bucket
• BShut off nearby engines, evacuate the area, eliminate ignition sources, and notify the ga…
• CLight a match to confirm the smell is gas
• DPour water into the trench to dilute the gas

For steel gas mains, why is coating integrity and cathodic protection important?

• AThey increase the pipe’s internal diameter
• BThey control external corrosion that can cause leaks and failures
• CThey eliminate the need for pressure testing
• DThey replace the need for qualified welders

When backfilling a gas trench under a future pavement section, which practice best protects the line and the pavement?

• ADump large rocks directly on the pipe for drainage
• BUse specified select material, remove rocks/debris from the pipe zone, and compact in lif…
• CLeave the trench open until the pavement contractor arrives months later
• DBackfill with frozen clods and organic topsoil only

A concrete pavement contractor must lower a segment of gas main for grade. Who typically must approve the method and perform or supervise the live-line work?

• AAny laborer on site with a shovel
• BThe gas operator / qualified gas contractor under operator procedures and applicable codes
• CThe concrete finisher only
• DThe trucking subcontractor delivering aggregate

What is the primary function of transverse contraction joints in jointed plain concrete pavement (JPCP)?

• ATo add decorative scoring only
• BTo control the location of shrinkage and temperature cracks by creating a weakened plane
• CTo permanently separate the slab into independent floating sections with no load transfer
• DTo eliminate the need for curing

Why are dowel bars used at transverse joints in concrete pavement?

• ATo chemically bond adjacent slabs into a monolithic mass
• BTo transfer vertical load between slabs while allowing horizontal joint opening and closi…
• CTo replace all aggregate in the mix
• DTo serve as the only form of curing compound

What is the main purpose of tiebars in longitudinal joints of concrete pavement?

• ATo allow free separation of lanes with no restraint
• BTo hold adjacent lanes together and maintain aggregate interlock / alignment
• CTo measure pavement temperature
• DTo replace surface texturing

When should contraction joints in concrete pavement typically be sawed?

• AAfter the pavement has been in service for 30 days
• BAs soon as the concrete has hardened enough to saw without raveling, and before random cr…
• COnly during freezing weather
• DNever—joints should only be tooled in plastic concrete for highways

What is the primary purpose of surface texturing (tining, grooving, or turf drag) on concrete pavement?

• ATo increase the water-cement ratio
• BTo improve tire-pavement friction and reduce wet-weather skidding
• CTo eliminate the need for joints
• DTo cure the concrete chemically

During slipform paving, what does a consistent, stable edge slump (edge drop) generally indicate?

• AThe mix is too dry and unworkable for finishing
• BThe mix workability and paving machine setup are reasonably balanced for free-edge support
• CThe pavement needs no curing
• DAir content is automatically within specification

What is the main reason for sealing concrete pavement joints?

• ATo increase slab thickness
• BTo keep incompressible debris and water out of the joint reservoir, reducing spalling and…
• CTo replace dowel bars
• DTo color the pavement for striping

Expansion joints in concrete pavement are primarily provided to:

• ACreate random cracks mid-panel
• BAccommodate larger thermal expansion movements at structures, intersections, or fixed obj…
• CEliminate all reinforcement
• DIncrease the cement content of the mix

What is “pumping” distress in concrete pavement?

• AIntentional injection of epoxy into sound joints
• BEjection of water and fine base material through joints or cracks under traffic loading
• CNormal curing bleed water only
• DAn increase in pavement friction

When matching new concrete pavement to existing pavement grade, stringlines or stringless 3D control systems are used primarily to:

• AMeasure concrete air content
• BControl elevation, cross slope, and alignment of the paver
• CDetermine cement brand only
• DReplace compaction of the base

Why is curing critical immediately after finishing concrete pavement?

• ATo raise the water-cement ratio after placement
• BTo retain moisture and control temperature so hydration continues and plastic/early-age c…
• CTo dissolve the surface texture
• DTo eliminate the need for joint sawing

A concrete pavement exhibits mid-panel transverse cracks shortly after placement. Which combination is a common contributing cause?

• AJoints sawed too early with perfect weather only
• BDelayed joint sawing, high shrinkage conditions, and/or base restraint
• CExcessive use of curing compound
• DDowel bars placed exactly at mid-depth

What is the primary purpose of compacting subgrade and base under concrete pavement?

• ATo increase the cement content of the slab
• BTo provide uniform, stable support and minimize differential settlement under traffic
• CTo eliminate the need for joints in the slab
• DTo raise the pavement’s design thickness automatically

Proctor tests (standard or modified) are used in earthwork primarily to determine:

• AThe color of the soil
• BMaximum dry density and optimum moisture content for compaction control
• CConcrete compressive strength
• DAsphalt binder grade

If a granular base is compacted on the dry side of optimum and will not densify, what is the usual corrective action?

• AAdd more dry powder and keep rolling without water
• BAdjust moisture toward optimum, rework the lift, and recompact
• CIncrease lift thickness to 3 feet uncompacted
• DSkip compaction if the surface looks smooth

Why must soft, organic, or pumping subgrade spots be undercut and replaced before placing concrete pavement?

• AOrganic soils increase concrete strength
• BNon-uniform weak support causes differential deflection, cracking, and early pavement fai…
• CUndercutting is only decorative
• DPumping soils automatically meet density without treatment

What is the purpose of fine grading (trimming) the base immediately before concrete paving?

• ATo create large surface ruts for drainage only
• BTo establish final elevation and cross slope within tight tolerance for uniform slab thic…
• CTo replace the need for stringline control on the paver
• DTo cure the concrete

Nuclear density gauges on base courses measure which primary field properties for acceptance?

• AOnly soil color and odor
• BWet density (and often moisture), used to compute dry density for comparison to Proctor
• CConcrete flexural strength directly
• DAsphalt PG grade

What is a key reason to place and compact base material in controlled lift thicknesses?

• AThicker single lifts always compact better with one pass
• BCompactive energy must reach full depth; excessive lift thickness leaves the bottom under…
• CLifts are only for asphalt, never aggregate base
• DLift thickness is unrelated to density

Positive surface drainage of the subgrade and base before paving is important because standing water can:

• AIncrease long-term concrete modulus automatically
• BSoften support, reduce density, and cause pumping and early distress under the slab
• CReplace the need for joint sealing forever
• DEliminate freeze-thaw risk in the concrete

Proof rolling of subgrade is primarily used to:

• AMeasure exact laboratory Proctor values
• BDetect soft, yielding, or unstable areas under a heavy roller or loaded truck before pavi…
• CApply the final concrete surface texture
• DInstall dowel baskets