CSLB Concrete C8 License Practice Test #2 correctly answered latest 2023

The maximum size of the conduit or pipe shall NOT exceed _______ of the thickness of the concrete. 1/3 Which of the following tests for concrete is conducted at the site/field? Color Test Explanation: Rest of the above are laboratory tests. If the concrete compressive strength specified is less than 3600 psi, it has the option of being tested at 28 days and is able to accept the concrete if it attains ___________ percentage of the minimum required strength. 85 If the admixtures are used in concrete for the purpose of delayed setting and hardening of concrete, they are called _____________? Retarders Which of the following are the general types of vibrating needles that are in use? ALL ANSWERS! -Internal vibrators -Immersion vibrators -Surface vibrators Concrete proportioning is done based on the facilities available at the site. Which are the general proportioning methods used for concrete? ALL OF THESE -Surface area method -Mix design based on flexural strength -Maximum destiny method The minimum cementitious material that is required for concrete bridging deck is ______________lbs/cu yd. 675 The amount of free water used in concrete shall not exceed ____________ pounds per cubic yard of concrete. 310 Explanation: If the SCM are added, it can be increased to 20 pounds per each required 100 pounds of cementitious material in excess of 550 pounds per cubic yard. If the concrete curbs are to be constructed over the existing pavement, _______________ are used to fix them to pavement. Steel dowels Which of the following is NOT an example of blended cement? Combination of silica fume and chlorine fluoride Explanation: Blended cement is a combination of either Type || or Type V cement with any of the SCM Which of the following is a line at which the face of the curb meets the top of the payment? Control Joint Which of the following is NOT used as concrete chemicals? Abrasion bonding compound Explanation: Concrete curing compound and polymer bonding agent are both concrete chemicals. The admixtures that are used in concrete to improve durability in freeze/thaw environments are ________________. Air entrainment admixtures The fly ash which is used as SCM has the specific gravity ___________________. 1.9 - 2.8 The leveling operation that removes lumps and hollows and provides a true and uniform concrete surface is called ______________________. Screeding If the quantity of concrete is less than _____________ cubic yards, the compliance test reports are not required. 50 Which type of Portland cement is used when early strength is expected? Type ||| Which of the following factor influence the positioning of the joints in a slab on grade? ALL OF THESE -Sub grade conditions -Finishing requirements -Temperature Which of the following is NOT a property of concrete? High tensile strength The concrete work is done in freezing zones, it gets cured by ______________. Steam Explanation: It is done by heating concrete by steam or using alternating current, so that water content in the concrete is not increased. Coarse aggregate in concrete is the material that is retained in sieve number ____________. #4 Explanation: The one which passes through sieve #4 is the fine aggregate. All of the structural steel is considered satisfactory even if it is rusted, but still meets the density requirements, except ___________________. Pre stressing steel Explanation: If the pre stressing steel is rusted, it cannot be used since it does not meet the compliance requirements. The compressive strength of concrete when treated with a 4" cube is always ____________ than when tested with a 6" cube. More The practice of making concrete to achieve the stipulated minimum strength and durability and to make concrete in the best economical manner is called _________________. Mix design Explanation: Mix design uses the theoretical calculations to get the desired higher strength in concrete but yet consuming minimum cement. What is the purpose of using SCM in concrete other than meeting workability requirements? To avoid emissions: The cement production is responsible for 7% of the greenhouse gas emissions (GHG). If the contractor has to transport the concrete, what is the specified time for the concrete after catching under normal circumstances? Before 1 1/2 hours Explanation: Or before 250 revolutions of the drum What is NOT a key purpose in using SCM in concrete? Short term curing period The rough concrete finishes are generally appropriate for surfaces subject to _______________. Traction Why would the cylindrical/circular columns be chosen over the square/rectangular columns? Circular columns carry more load. Explanation: For the given cross section area, circular columns carry more load as compared to square/rectangular columns. The size of the vibration needle to be used for concrete vibration for slab is ______________ inch. 3/4" (20mm) Explanation: It is based on the thickness of the slab, generally 3/4" needle is used and in rare cases 1 1/2" needle is also used. What are the compliance requirements that the concrete must meet to pass the acceptance test? ALL OF THESE! -Homogeneity -Strength -Workability The additives used to enhance the performance of concrete for the special purposes is/are called: Chemicals Explanation: Shall not be confused with admixtures Which of the following are the factors that affect the pulse velocity measurement on concrete? ALL OF THESE! Explanation: -Temperature on concrete -Presence of reinforcing steel -Smoothness of the surface Which of the following is NOT a concrete curing method? Water entrapment curing "Specific performance admixtures" are the admixtures that can provide a desired performance characteristics other than: ALL OF THESE -Reducing water content -Changing the setting time -Changing the functionality Construction joints in the pavement are generally created by ___________________. ALL OF THESE! -Scoring concrete with a grooving tool -Rounding corners with the edger tools -Saw cutting the hard concrete The average of the expansion of the aggregate at 16 days when tested in conformance with the requirements is less than or equal to ____________ percent. .15 Explanation: For one year and less the expansion limit is .040 percent The cement type that is recommended for rapid construction or cold weather is __________________. Type ||| According to Caltrans recommendations, air entraining admixtures are used in concrete in the climate zone _______________. ||| Explanation: Area ||| is classified as a severe climate, where freeze-thaw cycles and heavy salting occurs frequently and where chains are used. What is the minimum depth of excavation for the curbs below the sub grade? 6" In locations where fine aggregate is expensive or scarce, what can be used as an economical partial replacement? Air entraining admixtures Explanation: This is the air bubble that expands to reduce the requirements of fine aggregates, it also enhances the workability of fresh concrete and in turn reduces the water requirements. The activities carried out during concreting include but are not limited to: ALL OF THESE! -Batching -Placing -Compacting Explanation: In addition it includes mixing, transporting, curing etc. The function / value of the poissons ratio generally ___________________ with concrete mixing. Increases Explanation: Richer the mix, higher the value The minimum level at which the aggregates being tested is expected to comply, is referred to as Threshold Which of the following tools will be used to finish concrete that requires a dense and smooth finish? Steel trowel