Download PrepIQ Highlands County CONCRETE PLACING AND FINISHING ENGLISH OR SPANISH Ultimate Exam and more Exams Technology in PDF only on Docsity!
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OR SPANISH Ultimate Exam
Question 1. Which of the following is the primary purpose of testing soil compaction before placing a concrete slab? A) To determine the soil’s color B) To assess the soil’s load-bearing capacity C) To measure the soil’s pH D) To identify underground utilities Answer: B Explanation: Soil compaction testing verifies that the subgrade can support the slab’s loads without excessive settlement. Question 2. When removing organic material from a subgrade, which characteristic is most important to eliminate? A) High electrical conductivity B) Low thermal conductivity C) Decomposition that can cause future settlement D) Magnetic properties Answer: C Explanation: Organic material decomposes over time, leading to voids and settlement under the concrete. Question 3. Expansive soils are best stabilized by: A) Adding more sand B) Installing a vapor barrier C) Using lime or cement treatment D) Increasing the water-cement ratio Answer: C Explanation: Lime or cement reacts with expansive clays to reduce swelling and shrinkage. Question 4. The correct method for overlapping polyethylene vapor retarders on a slab is: A) 2-inch overlap with seams taped
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OR SPANISH Ultimate Exam
B) 6-inch overlap without tape C) 12-inch overlap with hot-melt adhesive D) No overlap is required Answer: A Explanation: A minimum 2-inch overlap, sealed with a compatible tape, ensures a continuous moisture barrier. Question 5. During reinforcement placement, the vapor barrier must be: A) Cut into pieces to fit around rebar B) Protected with a layer of sand or plywood C) Removed before placing any reinforcement D) Ignored, as it does not affect reinforcement Answer: B Explanation: Protecting the barrier prevents punctures and maintains its moisture-control function. Question 6. When interpreting a blueprint for slab dimensions, the term “overall length” refers to: A) The distance between the nearest support columns B) The total length of the slab measured at the finished grade line C) The length of the formwork only D) The length of the reinforcement bar layout Answer: B Explanation: Overall length is the full measurement of the slab at its intended finished elevation. Question 7. To establish the finish floor elevation, a crew should use: A) A hand-held ruler only B) A transit level or laser level with grade stakes C) A GPS device D) Visual estimation
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OR SPANISH Ultimate Exam
Question 11. The minimum spacing of stakes for a 6-inch-thick vertical form is: A) 24 inches on center B) 48 inches on center C) 72 inches on center D) 12 inches on center Answer: A Explanation: For 6-inch-thick forms, stakes are typically placed every 24 inches to resist pressure. Question 12. A “kicker” in formwork terminology refers to: A) A decorative edge strip B) A diagonal brace that resists outward pressure C) A type of form release agent D) A tool for smoothing concrete Answer: B Explanation: Kickers are diagonal members that counteract lateral forces on form panels. Question 13. According to OSHA, the earliest time a form can be stripped is when the concrete reaches: A) 30 psi compressive strength B) 70 % of its specified strength C) 100 % of its design strength D) 10 psi compressive strength Answer: B Explanation: OSHA permits stripping when concrete has achieved at least 70 % of its specified strength to avoid damage. Question 14. A construction joint keyway is installed to: A) Provide a decorative texture
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OR SPANISH Ultimate Exam
B) Allow for movement and prevent joint leakage C) Increase the slab’s tensile strength D) Reduce the need for reinforcement Answer: B Explanation: Keyways create a mechanical interlock that controls joint movement and prevents water intrusion. Question 15. Rebar size #5 corresponds to a diameter of: A) 0.5 inches B) 0.625 inches C) 0.75 inches D) 1.0 inches Answer: B Explanation: #5 rebar has a nominal diameter of 0.625 inches (5/8"). Question 16. The term “grade” for rebar refers to: A) The length of the bar B) The tensile strength class (e.g., Grade 60) C) The amount of corrosion resistance D) The bar’s coating type Answer: B Explanation: Rebar grade specifies the minimum yield strength, such as Grade 60 for 60,000 psi. Question 17. Minimum clear cover for interior slabs in Florida residential construction is: A) 1/2 inch B) 3/4 inch C) 1 inch D) 1 ½ inch Answer: B
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A. High-early-strength applications in hot climates B. Sulfate-resistant concrete in marine environments C. Low-heat mass concrete pours D. Decorative colored concrete Answer: A Explanation: Type III cement has a higher early strength gain, useful in hot Florida conditions. Question 22. The most common maximum aggregate size for a 4-inch-thick slab is: A) ¾ inch B) ½ inch C) 1 inch D) 1¼ inch Answer: B Explanation: For a 4-inch slab, aggregate should not exceed ½ inch to ensure proper placement and finish. Question 23. A water-cement ratio of 0.45 typically yields a concrete compressive strength of approximately: A) 2,500 psi B) 3,500 psi C) 4,500 psi D) 6,000 psi Answer: C Explanation: A 0.45 ratio is commonly associated with 4,500 psi strength, assuming proper mix design and curing. Question 24. An air-entraining admixture is added to concrete primarily to: A) Increase early strength B) Improve resistance to freeze-thaw cycles C) Reduce water demand
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D) Accelerate setting time Answer: B Explanation: Air bubbles provide space for water expansion during freezing, enhancing durability. Question 25. Superplasticizers are used when a concrete mix requires: A) Low slump (≤2 inches) B) High slump (≥6 inches) without adding extra water C) Faster setting time in cold weather D) Increased air content Answer: B Explanation: Superplasticizers increase workability (high slump) while maintaining low water-cement ratios. Question 26. The slump test measures: A) Concrete compressive strength B) Consistency or workability of fresh concrete C) Air content D) Temperature of the mix Answer: B Explanation: Slump indicates the flowability of fresh concrete and helps verify mix design. Question 27. When casting concrete cylinders for compressive testing, the standard dimensions are: A) 4 inches diameter × 8 inches height B) 6 inches diameter × 12 inches height C) 8 inches diameter × 16 inches height D) 10 inches diameter × 20 inches height Answer: B Explanation: ASTM C39 specifies 6 × 12 in. cylinders for compressive strength testing.
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B) Remove excess water and level high spots after screeding C) Cut control joints D) Apply curing compound Answer: B Explanation: Bull floating smooths the surface and eliminates low/high spots before finishing. Question 32. Bleed water must be allowed to disappear before which finishing step? A) Bull floating B) Hand-troweling C) Broom finishing D) Applying a curing compound Answer: B Explanation: Hand-troweling should occur after bleed water evaporates to avoid trapping water on the surface. Question 33. Grooving a slab to create control joints is typically done at a depth of: A) ¼ of slab thickness B) ½ of slab thickness C) ⅓ of slab thickness D) Full slab thickness Answer: A Explanation: Control joints are usually cut to a depth of ¼ the slab thickness to control cracking. Question 34. A broom finish is most appropriate for: A) Interior polished floors B) Outdoor walkways requiring slip resistance C) Decorative stamped concrete D) Exposed aggregate surfaces
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Answer: B Explanation: Brooming creates a textured surface that improves traction on exterior slabs. Question 35. Stamped concrete is created by: A) Adding pigments to the mix B) Pressing a pattern into freshly placed concrete with a stamp C) Using a high-strength polymer overlay D) Embedding metal plates before curing Answer: B Explanation: Stamping involves impressing a patterned mat into the concrete surface before it sets. Question 36. The most common curing method for a residential slab in Florida is: A) Covering with wet burlap for 24 hours B) Applying a liquid curing compound and keeping the surface moist for 7 days C) Immediate removal of forms and allowing air drying D) Using a heated enclosure to speed up curing Answer: B Explanation: Liquid curing compounds are widely used to retain moisture and meet VOC regulations. Question 37. Minimum curing time before applying a light load to a 4-inch slab is: A) 6 hours B) 12 hours C) 24 hours D) 48 hours Answer: C Explanation: A 24-hour cure is generally required to develop sufficient strength for light traffic.
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B) 0.10 mg/m³ averaged over a 12-hour shift C) 0.25 mg/m³ averaged over a 10-hour shift D) 1.0 mg/m³ averaged over a 24-hour shift Answer: A Explanation: OSHA’s PEL for respirable crystalline silica is 0.05 mg/m³ over an 8 - hour TWA. Question 42. According to the Florida Building Code, the minimum slope for a residential driveway is: A) 1: B) 1: C) 1: D) 1: Answer: B Explanation: The FBC requires a maximum slope of 1:12 (approximately 8.33%) for residential driveways. Question 43. ADA requirements for a wheelchair ramp slope dictate a maximum of: A) 1: B) 1: C) 1: D) 1: Answer: C Explanation: The ADA specifies a 1:12 slope as the maximum for accessible ramps. Question 44. The term “wet curing” refers to: A) Applying a polymer overlay after the slab has dried B) Keeping the concrete surface continuously moist during the early curing period C) Spraying a water-repellent sealant on the cured slab
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D) Using a high-temperature steam cure chamber Answer: B Explanation: Wet curing maintains moisture, preventing premature drying and enhancing strength gain. Question 45. A common cause of “honeycombing” in concrete is: A) Excessive air-entraining admixture B) Insufficient vibration leading to voids C) Over-mixing the concrete D) Using too much superplasticizer Answer: B Explanation: Lack of proper consolidation leaves voids that appear as honeycomb patterns. Question 46. When placing concrete in hot, humid Florida weather, the recommended adjustment is to: A) Increase the water-cement ratio by 15 % B) Use a retardant admixture to slow the set time C. Add more cement to speed up strength gain D. Reduce the slump to 1 inch Answer: B Explanation: Retarders delay setting, allowing more working time in high temperatures. Question 47. The purpose of a “keyway” in a construction joint is to: A) Provide a decorative groove B) Increase shear transfer across the joint C. Reduce the amount of reinforcement needed D. Allow water to drain through the joint Answer: B Explanation: Keyways create a mechanical interlock that improves shear resistance across the joint.
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OR SPANISH Ultimate Exam
A) It eliminates the need for vibration B) It is only used for decorative overlays C) It reduces shrinkage cracking by minimizing water loss D. It is prohibited by the Florida Building Code Answer: C Explanation: Dry placement (low water-cement ratio) reduces drying shrinkage and associated cracking. Question 52. The term “bleed water” refers to: A) Water that evaporates from the concrete surface during curing B) Water that rises to the surface after placement due to settlement of solids C. Water added to the mix to increase slump D. Water used to wet the formwork before placement Answer: B Explanation: Bleed water is the excess water that migrates upward as the concrete settles. Question 53. When using a concrete pump, the maximum recommended drop height to prevent segregation is: A) 6 feet B) 12 feet C) 18 feet D) 24 feet Answer: B Explanation: Drops greater than 12 feet can cause excessive agitation and segregation. Question 54. The term “sag” in concrete placement refers to: A) The intentional dip created for decorative purposes B) Uncontrolled lowering of concrete under its own weight before it sets C) The vertical movement of forms during curing D. The reduction of slump over time
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OR SPANISH Ultimate Exam
Answer: B Explanation: Sag occurs when concrete flows downward before gaining enough strength to hold shape. Question 55. Which of the following is the most effective way to prevent “cold joints” when placing concrete in multiple lifts? A) Use a high-early-strength cement in all lifts B) Ensure each lift is placed within the initial set time of the previous lift C. Increase the slump of each subsequent lift D. Apply a bonding agent to the surface of the previous lift Answer: B Explanation: Placing lifts before the previous layer sets creates a monolithic bond, eliminating cold joints. Question 56. A “saw cut” joint is typically made after: A) The concrete has reached 50 % of its design strength B) The concrete has cured for at least 7 days C. The concrete has achieved full strength (28 days) D. The slab has been polished Answer: B Explanation: Saw cuts are usually made after 7 days when the concrete has sufficient strength to withstand the cutting stress. Question 57. For a slab with a thickness of 5 inches, the recommended spacing of control joints is: A) 6 feet B) 8 feet C) 10 feet D) 12 feet Answer: C Explanation: Joint spacing is often 24–30 times the slab thickness; 5 in × 24 = 120 in (10 ft).
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C. It speeds up the curing process by heating the surface D. It eliminates the need for any other curing method Answer: B Explanation: Plastic sheeting traps moisture, maintaining a humid environment for curing. Question 62. Which of the following is a correct statement about “shrinkage cracking”? A) It only occurs in the first hour after placement B) It can be minimized by proper curing and control joint design C. It is eliminated by using a higher water-cement ratio D. It is unrelated to reinforcement cover Answer: B Explanation: Adequate curing and control joints help control the tensile stresses that cause shrinkage cracks. Question 63. A “hand-trowel” finish is most appropriate for: A) Exterior sidewalks requiring slip resistance B) Interior floors where a smooth surface is desired C. Stamped decorative concrete D. Exposed aggregate surfaces Answer: B Explanation: Hand-troweling creates a dense, smooth finish ideal for indoor applications. Question 64. The correct method to protect a vapor barrier during rebar placement is to: A) Place a layer of sand over the barrier before installing rebar chairs B. Use rebar chairs with a flat steel plate that does not pierce the barrier C. Cut the barrier around each piece of rebar D. No protection is needed; rebar can be placed directly on the barrier Answer: B
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OR SPANISH Ultimate Exam
Explanation: Chairs with a flat base distribute load without puncturing the vapor barrier. Question 65. In the context of concrete, “air-void system” refers to: A) The intentional placement of large voids for weight reduction B) The distribution of microscopic air bubbles that improve freeze-thaw durability C. The network of cracks that develop after curing D. The voids created by improper vibration Answer: B Explanation: Properly distributed microscopic air bubbles form an air-void system that protects against freeze-thaw damage. Question 66. The term “slump flow” is used in: A. Conventional slump testing only B. Self-consolidating concrete (SCC) testing C. Reinforced steel bar design D. Curing compound application Answer: B Explanation: Slump flow measures the spread of SCC, indicating its flowability without vibration. Question 67. When a concrete slab is being cured with wet burlap, the burlap must be: A) Kept dry to absorb excess moisture B. Kept continuously wet throughout the curing period C. Removed after 2 hours to allow drying D. Replaced with plastic sheeting after 12 hours Answer: B Explanation: Wet burlap maintains a moist environment, preventing premature drying. Question 68. The primary purpose of a “control joint filler” is to:
