Cement Short Quizzes PDF

## B Short Quiz 1 on Cement: - What is the basis of the strength of cement? - Based on concrete cylindrical test - Based on ASTM C109 - Based on ASTM C190 - Based on ASTM C348 - What are the compounds that contribute much to the hydration of cement? - tetracalcium aluminoferrit...

## B Short Quiz 1 on Cement: - What is the basis of the strength of cement? - Based on concrete cylindrical test - Based on ASTM C109 - Based on ASTM C190 - Based on ASTM C348 - What are the compounds that contribute much to the hydration of cement? - tetracalcium aluminoferrite - tricalcium aluminate - tricalcium silicate - dicalcium silicate - List one of the four ingredients of cement. - Calcium, Aluminum, Silicon, Iron - What is the standard specific gravity of cement? - 3.15 - What is the usual liquid used in determining the specific gravity of cement? - Kerosene - Gasoline - Water - Vinegar - What compound prevents flash setting? - Diacalcium silicate - Gypsum - Calcium hydroxide - Calcium silicate hydrate - What do we call the ability of cement not to undergo large change in volume during hydration? - Soundness - Fineness - Shrinkage - Exothermic ## What are the characteristics of pozzolan? - react with calcium hydroxide - siliceous/aluminous material - blended cement - natural cementitious material ## The term hydration refers to the chemical reaction between cement, water, aggregates. - True - False ## Fineness of cement affects the following: - Cost of heating - Rate of hydration - Gypsum requirement - Amount of clinker produced ## Short Quiz 2 on Aggregates: - What is the average diameter of the aggregates if the fineness modulus is 3.0? Answer in mm up to 1 decimal place. - 0.6 - Among the choices, which are the mechanical properties of aggregates? - Bond - Strength - Toughness - Durability - What are affected by the shape of aggregates? - Water requirement - Void content - Bond area - Durability - What is considered as the best shape of coarse aggregates for concreting job? - Angular - Round - Flaky - Pointed - Among the choices, which are the physical properties of aggregates? - Specific gravity - Absorption - Grading - Soundness - What is one of the ideal textures of aggregates for concreting job? - Rough - Smooth - Honeycombed - Glassy - Which one is the desired grain size distribution or grading of aggregates to produce good concrete? - Well graded - Flat graded - Gap graded - Uniformly graded - Which are the basis of the maximum size of aggregates? - Dimension of concrete member - Spacing of rebars - Sieve analysis - Size of rebar - What are inert and inexpensive material that occupies large percentage volume of concrete? - Aggregates - If the percentage absorption of aggregates is 5%, what is the specific gravity at oven dried condition if the specific gravity at SSD condition is 2.35? Round-off up to 2 decimal places. - 2.24 - What are the characteristics of concrete that aggregates affect? - Workability - Strength - Cost - If the rebar spacing is 1 inch (25.4 mm), what is the aggregate size (mm) that will produce the most economical concrete? - 3/4" - 1" - 1/2" - 3/8" ## Short Quiz 3 on Water and Admixture: - What are the effects of plasticizer in a concrete mix? - increase water content - increase early strength - increase workability - waterproof concrete - What should be the acceptable quality of water for a concrete mix? - potable water - purified water - water free from impurities - rainwater - What admixture do we use to advance the time that a structure can be made in service? - Accelerator - The water inside the aggregates (or absorbed by the aggregates) shall be included in calculating the amount of water added to the concrete mix. - True - False - Accelerator can be used with set retarder in a concrete mix. - True - False - What is the best admixture to produce self-compacting concrete? - Superplasticizer - What is this pozzolan in the form finely divided residue which is a by-product of coal combustion? - Fly Ash - Which are the effects of set retarder in a concrete mix? - Improve workability - Lessen formation of cold joints - Reduce early strength - Hasten the hardening of concrete - Among the choices, which are admixtures? - Retarder - Pozzolan - Plasticizer - Accelerator - Which admixture(s) can be used to produce high strength concrete? - Plasticizer - Accelerator - Silica fume - Air-entraining admixture ## Short Quiz 4 on Fresh Concrete: - Is the strength of concrete affected by the workability of fresh concrete? - Yes, to some extent - Yes, but consolidation can cure it - No effect at all - What are the different methods of determining the air content of fresh concrete? - Volumetric method - Pressure method - Penetration method - Gravimetric method - Among those listed below, which are measurable properties of fresh concrete? - Workability - Air content - Bleeding - Segregation - What is another term for shotcrete? - Gunite - What is the term for putting concrete ingredients into a concrete mixer? - Charging - Choose from the list below which ones are the purpose of curing? - Enhanced hydration of concrete - Improve concrete surface - Remove impurities from concrete - Prevent water evaporation - What is the property of fresh concrete defining the time required to reach the specified value of resistance to penetration? - Setting time - What are the causes of shrinkage of concrete? - Loss of water due to evaporation - Overcompaction of concrete - Loss of water in hydration - Heat of hydration - What is the method used to deposit concrete under water? - Tremie - What are the factors affecting workability of fresh concrete? - Air content - Maximum size of aggregates - Aggregate grading - Density of aggregates - Water content - What are the purposes of vibrating fresh concrete? - Provide additional workability - Remove entrapped air - Proper filling of forms - Introduce air entrainment - What are the advantages of ready-mix acceptaconcrete? - Cheaper - Can be used in congested site - Good quality control - No problem in workability - What are the possible causes of segregation of fresh concrete? - improper vibration - use of river gravel - incorrect manner of transport - gap grading - What is the term used for fresh concrete pumped under pressure - Pumpcrete - Shotcrete - Forced concrete - Batched concrete - What are the acceptable curing method of concrete in the list shown below? - Spying with mortar - Ponding with water - Covering with wet sand or soil - Covering with cement - What are the tests that can used to measure the workability of fresh concrete? - Slump test - Flow test - Drop test - Flow table test - Ball penetration test - What is the type of shrinkage caused by water being used up in hydration? - Autogeneous - What are the different forms of segregation in fresh concrete? - Bleeding - concrete slump - separation of cement paste - separation of coarser aggregates - A harsh concrete is a fresh concrete that is difficult to mix. - True - Which one below is the acceptable diameter of pipe for pumping concrete if the maximum aggregate size is 19 mm? - 60 mm - 50 mm - 30 mm - 40 mm - What is the term used in coating the inner sides of the mixer with an initial amount of mortar or cement paste? - Buttering ## Short Quiz 5 on Hard Concrete: - What are the acceptable sizes of specimen for compression test of concrete - 50 mm cube - 6" x 12" cylinders - 100 mm x 200 mm cylinders - 6" cubes - What are some of the mechanical properties of hard concrete - Modulus of elasticity - Compressive strength - Poisson's ratio - Density - The compressive strength of concrete used in structural design is obtained on how many days after mixing concrete? - 28 days - 60 days - 14 days - 30 days - What is assumed density of normal weight concrete in kg/cu.m.? - 2400 - The concrete stress-strain curve is considered to be elastic up to what percentage of f'c? - 50 - Which one is the acceptable and realistic value of Poisson's ratio of concrete? - 0.30 - 0.10 - 0.20 - 0.40 - The shape of the standard specimen used for determining the compressive strength and split-tensile strength of concrete? - beam - cube - prism - cylinder - If the compressive strength (f'c) of concrete is 21 MPa, what is the modulus of rupture of concrete (in MPa) according to the Code? (rounf off up to 2 decimal places) - 2.84 - Solution: - f = 0.62√fc' = 0.62√21 = 2.84 MPa - What contributes to the strength of concrete? - Strength of aggregates - Strength of admixture - Strength of cement - Strength of bond - What is the term used for the long-term deformation of concrete due to application of sustained load? - Creep - If the compressive strength of normal weight concrete is 28 MPa, which one is the value of the modulus of elasticity, Ec? - 21,538 MPa - 25.800 MPa - 24,870 MPa - 20,000 MPa