ACI Concrete Finisher Practice Test

These questions are part of the practice quiz. Start practicing

• For floor flatness evaluation, which straightedge length is specified for measuring the gap?
• What is the function of a darby or magnesium float in finishing?
• What is slump and why is it important to the finisher?
• Wood hand floats are best for which concrete condition?
• PPE is mandatory for finishers on most sites. Which set is correct?
• What is the most common finishing sequence for a typical slab on grade?
• What is an air-entraining admixture used for and how does it affect finishing?
• Early entry dry cut saws cut the waiting period before sawing to as little as ________ in hot weather and about _________ in cold weather.
• On a slab treated with both machine and hand finishes, what would a spec sheet most likely call out as an issue needing resolution?
• Power trowels can be used for floating or troweling.
• A drying period after curing increases resistance to freezing and thawing damage. Which statement best describes this effect?
• How do you prevent cold joints in a single placement?
• When is it appropriate to remove forms from a concrete slab that was placed against them?
• Which condition indicates that floating is appropriate to begin finishing?
• Before concreting, workers should check the elevation of the subbase by:
• Which finish inconsistency is most likely to be noticed by occupants after the floor has cured?
• What is the primary purpose of a control joint in a concrete slab?
• The presence of two tonal areas on a floor suggests what about the finishing process?
• Laitance definition and effect.
• If concrete is kept at a temperature of 50 degrees for one day, what compressive strength is typically reached to prevent damage from freezing?
• Which two floor properties does the F-number system evaluate?
• Why should curing compounds not be used on exterior concrete placed during fall or cold weather?
• A gallon of curing compound generally covers between what range of slab surface?
• F-number testing should preferably be done within how many hours after concrete placement, and never later than how many hours?
• What happens when concrete temperature is outside the recommended range?
• Highway straight edges are used to cut and fill concrete surfaces at which orientation to the construction joint?
• Where should the gap be measured when using a straightedge to check flatness?
• Finishers must hit the gap in the window of finish ability to avoid which pair of problems?
• When should control joints be planned and installed in concrete slabs?
• When should curing compounds be applied?
• Delaying troweling until the concrete is too stiff to close up reduces the possibility of delamination and makes it easier to achieve high flatness F-numbers. True or False?
• Which is a likely reason for color variation on a floor finished with both machine and hand tools?
• Measuring the gap under a 10 ft straightedge is a method to determine which property?
• Backer rod use in joint sealing?
• In hot weather, when slab curing may start after placing but before finishing, which two methods can be used?
• Who is responsible for reading and understanding project specifications?
• Retarding admixtures used in hot-weather concrete reduce the possibility of surface crusting. True or False?
• Before troweling, what must have been done first to the surface?
• Typical reason for surface dusting after curing and how to prevent?
• What term best describes the visual variation observed between machine-floated and hand-floated sections of a concrete floor?
• What is cold weather concreting and what finishing considerations apply?
• Which statement about a fine broom finish is accurate?
• Why is timing critical between finishing steps?
• On stiffer concrete, a forward-turn, forward-pass combination on a rider allows the finish to always ________ the concrete being floated or troweled.
• How do you perform a field slump test?
• How should you measure and control concrete temperature on site and why matters to finishing?
• Truck-mounted conveyors are especially useful on jobs with which condition?
• The contraction joint spacing rule is described as spacing in feet should be 2-3 times slab thickness in inches. Which option correctly states this rule?
• How do you perform proper joint sealant installation in expansion joints?
• If blisters do form, what should you do to the trowel blades and what kind of float should you reopen the surface with?
• Which statement describes the function of vibrators during placement?
• Keyed construction joints are not recommended for slabs less than how thick?
• The direction of the first machine floating pass should be ____________ to the direction of the last finishing procedure.
• What happens if finishing steps are performed before the previous set?
• What curing practice helps prevent surface dusting?
• Joints that separate slabs from walls and columns are called ___________ joints.
• What considerations apply when finishing vertical surfaces like walls?
• A ______ diameter pan is the largest size commonly used on walk-behind machines.
• What is the primary purpose of using a bull float after initial screeding?
• When concrete is placed by crane and bucket, buckets must never be lifted over which paths?
• What is meant by 'finish order' in concrete finishing?
• What is the purpose of backer rod in expansion joint installation?
• Edging and jointing is not required on most floors and should not be done unless specified.
• When some areas of a floor are machine floated and troweled but other areas must be hand floated, what is likely in the finished surface?
• If trowel drag occurs due to moisture, what is the recommended correction?
• What distinguishes wet curing from membrane curing?
• Increasing the amount of sand in concrete usually decreases the amount of water needed to make the concrete workable.
• Which tool is commonly used for hand spreading concrete in slabs?
• What does a screed establish on a slab?
• On stiffer concrete, the effect of a forward-turn, forward-pass on a rider is to ensure the finish faces the concrete.
• When planning a floor installation, why is it important to standardize finishing methods across the entire area?
• Which step in the finishing sequence most directly reduces small surface imperfections before the final trowel pass?
• How do you perform an air content test in the field, and what is a typical acceptable range?
• Missing the window of finish ability can lead to surface defects and failure to achieve what?
• ____________ bull floats are less likely to seal the surface.
• Bulls floats are used when achieving which specific F-number floor flatness?
• Why is broom finish often recommended for exterior slabs?
• What is the difference between a floating finish and a trowel finish?
• What purpose do warmers and blankets serve in cold weather concreting?
• Magnesium bull floats are suitable for finishing concrete that is:
• What is the purpose of curing compounds and how are they applied?
• Which spacing is the rule of thumb for a long, wide slab if thickness is known?
• If you observe a floor with two tones after finishing, this indicates?
• Which instruction is commonly required on drawings for SOG regarding reinforcing steel at joints?
• Which action is an effective method to maintain moisture on the concrete surface during curing on hot or windy days?
• Floating and toweling a concrete slab too soon can cause which problems?
• What is hot weather concreting and what finishing considerations apply?
• Which finish is described as possibly including a broom texture if desired?
• Hand-held vibrating screeds are often useful when striking off concrete with ______.
• If a foreman notices color mismatch across a floor, what underlying cause is most likely?
• Control joint spacing rule of thumb for a long, wide slab?
• In mixed finishing, what would be the primary aesthetic concern for clients?
• Portland cement will set and harden under water. Which of the following best describes this property?
• How do you identify when to perform the first trowel pass?
• Slabs at isolation joints must be free to move horizontally but not vertically. True or false.
• Isolation joints separate slabs from walls and columns; what is the term used for these joints?
• During cold weather, placing warm concrete on a cold subgrade is not ideal. It is best to have the warm concrete temp no more than _____ higher than the temp of the base.
• Which cement type is most appropriate when sulfate exposure is not present in a slab on ground?
• Chatter or washboard marks on a finished surface are caused by tilting the trowel blade too much or too soon.
• Which item might be required as additional PPE beyond standard on some sites?
• Which practice best confirms there are no voids near formwork after finishing?
• Spacing of contraction joints is often based on the rule that the spacing in _____ should be ____ to ____ times the slab thickness in _____
• Why is adequate concrete cover important around reinforcing steel during finishing?
• What is the main result of the final steel trowel finish on a concrete slab?
• Edgers are used to make neat, _____ edges primarily on ______ concrete.
• What is a common consequence of finishing a concrete slab too soon after placement?
• Around openings, what finishing steps should be performed to ensure edge quality?
• What tool is used to establish the final grade and slope on a slab?
• What is laitance and how can it affect finishing?
• What is the effect of sealing or densifying treatment after curing?
• Tilt of the trowel blade is excessive if the edge is more than ______ above the concrete surface.
• A drying period following curing increases resistance to damage caused by freezing and thawing. True or False?
• What is the primary function of welded wire reinforcement in slabs-on-grade that are considered unreinforced?
• When guiding a truck near a 6 ft deep excavation, the wheels closest to the edge should be at least how many feet away?
• Which statement best describes the purpose of edge finishing?
• Which material bull floats are less likely to seal the surface?
• What is the most direct indicator of mixed finishing methods affecting surface appearance?
• Tools commonly used for hand spreading concrete in slabs include which of the following?
• Concrete kept at a temperature of how many degrees for one day will usually reach the 500 psi compressive strength needed to prevent damage from freezing?
• Name two common finishing hazards on a job site and how to mitigate them.
• The action that reduces sealing when using a magnesium bull float is to
• To maintain a uniform appearance on a floor, what should be avoided when performing finishing operations?
• What should be done after form removal when a release agent was used?
• Troweling follows immediately after which step?
• What is the role of a release agent in decorative concrete?
• In hot weather finishing, which measures help prevent flash set?
• Which cement type is typically used for a ground-supported slab when sulfate exposure is not a concern?
• Define bleed water and its impact on finishing.
• If a concrete slab on ground is not exposed to sulfates, the cement used is most likely to be:
• The difference between two sections finished with different methods is most likely to affect which aesthetic aspect?
• Which practice helps prevent chipping during finishing around openings?
• What causes trowel drag and how can you fix it on a finished slab?
• Concrete is ready for floating when the bleed water sheen is gone and a finisher can walk on the slab leaving only about a ______ footprint.
• What is edge finishing and why is it important?
• When should a broom finish be applied on a concrete slab?
• Which statement about the effect of sand content on water demand is correct?
• Recommended sequence for beveling and edging around openings?
• Granular subbases for slabs on ground can be compacted with sheepsfoot rollers. True or False?
• What should you check before finishing a slab to ensure good surface quality?
• Slabs at isolation joints must be free to move horizontally but not vertically. True or false.
• To move left with a walk-behind troweling machine, which action is correct?
• When hand floating finishers should always start with the ___________ and then move to the ____________ size of float.
• Curing compounds should not be used on exterior concrete placed during fall or cold weather because they may not wear off in time for concrete to dry. True or False?
• Overworking the surface during finishing can cause which combination of effects on the final appearance?
• Which outcome would be flagged as a problem by a quality control checklist when different finishing methods are used side by side?
• The F-number system is a method for determining which floor characteristics?
• When concrete for a slab placement is discharged from the truck chute, how should truck arrivals be spaced?
• Drawings for joints in SOG typically require reinforcement to be discontinued at the joint. What is the typical intent described?
• Which option correctly matches a common surface defect with its remedy?
• An admixture that reduces bleeding while retarding setting will aggravate crusting problems. True or False?
• What is popout and how can you prevent it?
• Bull floating must be done after all the bleed water has evaporated from the surface. True or False?
• How are curing compounds typically applied?
• Why should bleed water be checked before finishing a slab?
• Most concrete used in slabs on ground has coarse aggregate with a maximum size of:
• Edging and jointing should be performed when?
• When using a magnesium bull float, sealing the concrete surface is less likely if you:
• What is scaling in concrete finishing and how can it be prevented?
• What is the difference between a control joint and an expansion joint?
• Which statement accurately describes the purpose of welded wire reinforcement in unreinforced SOG?
• Edgers primarily create edges on exterior concrete that are described as:
• If contraction joints are cut too soon the joint may ______ but if too late random __________ can occur.
• What is a key goal of proper consolidation near rebar?
• Portland cement will set and harden under water: True or False?
• To move left with a walk-behind troweling machine, which action is recommended?
• Aside from slip resistance, what is another benefit of a broom finish on exterior slabs?
• A fine broom finish is occasionally required for interior flatwork.
• Using a squeegee to remove water should be done when only water, not _____, is removed.
• At which meeting should the question about which finisher(s) can request water additions to the concrete be answered?
• Which method most reliably verifies adequate consolidation near formwork without saw cutting?
• Which practice helps when finishing concrete around reinforcing bars?
• What is the expected conclusion if both machine and hand finishing are used on the same floor?
• Which statement is true regarding the use of a 3 inch thick layer of manufactured sand on the vapor retarder?
• How should you prepare a concrete surface for curing on a hot day?
• What concrete do you use magnesium bull floats on?
• when specifications don't require a concrete slab to be in direct contact with the vapor retarder, the preferred method for reducing potential problems caused by slab curing is:
• What is a disadvantage of using trailer pumps for SOG placements?
• In decorative concrete, what is the purpose of a release agent and how should it be used?
• How do you check that control joints are cut to the correct depth?
• In excavation safety, what is the recommended minimum distance between a truck wheel and the excavation edge?