LQ1-SQs PDF Past Paper

LQ1 MATEL What compound prevents flash setting? - Gypsum - Calcium silicate hydrate - Dicalcium silicate - Calcium hydroxide What are the characteristics of pozzolan - React with calcium hydroxide - Blended cement - Natural cementitious material -...

LQ1 MATEL What compound prevents flash setting? - Gypsum - Calcium silicate hydrate - Dicalcium silicate - Calcium hydroxide What are the characteristics of pozzolan - React with calcium hydroxide - Blended cement - Natural cementitious material - Siliceous/ aluminous material Fineness of cement affects the following - Amount of clinker produced - Rate of hydration - Const of heating - Gypsum requirement What do we call the ability of cement not to undergo large change in volume during hydration? - Exothermic - Fineness - Shrinkage - Soundness What is the basis of the strength of cement? - Based on ASTM C190 - Based on concrete cylindrical test - Based on ASTM C348 - Based on ASTM C109 What is the usual liquid used in determining the specific gravity of cement? - Water - Vinegar - Gasoline - Kerosene The term hydration refers to the chemical reaction between cement, water, and aggregates - True - False What are the compounds that contribute much to the hydration of cement - Tricalcium silicate - Dicalcium silicate  - Tetracalcium aluminoferrite - Tricalcium aluminate What is the standard specific gravity of cement 3.15 What are the inert and inexpensive material that occupies large percentage volume of concrete? Aggregates If the rebare spacing is 1 inch (25.44mm), what is the aggregate siz (mm) that will produce the most economical concrete? - ¾” - 1” - ½” - 3/8” What are affected by the shape of aggregates? - Water requirement - Void ratio - Bond area - Durability If the percentage absorption of aggregate is 5%, what is its specific gravity at oven dried condition if the specific gravity at SSD condition is 2.35? 2.24 Which one is an ideal texture 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 What is the average diameter of aggregates if the fineness modulus is 3.0? 0.6 Among the choices, which are the physical properties of aggregates? - Specific gravity - Absorption - Grading - Soundness Among the choices which are the mechanical properties of aggregates - Bond - Strength - Toughness - Durability What admixture do we use to advance the time that a structure can be made in service accelerator Accelerator can be used with set retarder in concrete mix. - True - False Which admixtures can be used to produce high strength concrete? - Plasticizer - Air-entraining admixture - Accelerator - Silica fume Which are the effects of a set retarder in a concrete mix? - Reduce early strength - Improve workability - Lessen formation of cold joints - Hasten the hardening of concrete What are the effects of plasticizer in a concrete mix? - Increase workability - Increase early strength - Waterproof concrete - Increase water content What should be the acceptable quality of water for a concrete mix? - Purified water - Water free from impurities - Rainwater - Potable water Is the strength of hard concrete affected by the workability of fresh concrete? - Yes, to some extent. - No effect at all - Yes, but consolidation can cure it What are the purposes of vibrating fresh concrete? - Proper filling of forms - Provide additional workability - Introduce air entrainment  - Remove entrapped air What are the causes of shrinkage in concrete? - Loss of water due to evaporation - Heat of hydration - Loss of water in hydration - Ove compaction of concrete What are the advantages of ready-mix concrete - No problem in workability - Good quality control - Can be used in congested site - Cheaper What are the different methods in determining the air content of fresh concrete? - Volumetric method - Penetration method - Gravimetric method - Pressure method Chose from the list below which ones are the purpose of curing - Improve concrete surface - Remove impurities from concrete - Prevent water evaporation - Enhanced hydration of concrete What is the term used in coating the inner sides of the mixer with an initial amount to of mortar or cement paste? buttering What is another term for shotcrete gunite Which one below is the acceptable diameter of pipe for pumping oncrete if the maximum aggregate size is 19 mm? - 40mm - 30mm - 50mm - 60mm A harsh concrete is a fresh concrete that is difficult to mix - True - False What is the term used for fresh concrete pumped underpressure? - Forced concrete - Shotcrete  - Pumpcrete - Batched concrete Among those listed below, which are the measurable properties of fresh concrete? - Workability - Bleeding - Segregation - Air-content What are the possible causes of segregation of fresh concrete? - Gap grading - Improper vibration - Use of river gravel - Incorrect manner of transport What is the property of fresh concrete defining the time required to reach the specified vale of resistance to penetration? Setting Time What are the factors affecting workability of fresh concrete? - Water content - Aggregate grading - Maximum size of aggregates - Air content - Density of aggregates What is the method used to deposit concrete under water? tremie What are the acceptable sizes of specimen for compression test of concrete? - 100mm x 200mm cylinders - 6” cubes - 50mm cube - 6” x 12” cylinders What contributes to the strength of concrete - Strength of aggregates - Strength of bond - Strength of cement - Strength of admixture What are some of the mechanical properties of hard concrete? - Modulus of elasticity - Compressive strength - Density - Posson’s ratio Whach one is the acceptable and realistic value of Poisson’s ratio of concrete? - 0.1 - 0.2 - 0.3 - 0.4 Whate is the assumed density of normal weight concrete in kg/cum? 2400 The concrete stress-strain curve is considered to be elastic up to what percentage of f ’c? 50 If the compressive strength of normal weight concrete is 28 MPa, which one is the value of the modulus of elasticity, Ec? - 20,000 MPa - 25,800 MPa - 21,538 MPa - 24,870 MPa What is the term used for the long-term deformation of concrete due to application of sustained load? creep The compressive strength of concrete used in structural design is obtained on how many days after mixing concrete. - 30 days - 14 days - 28 days - 60 days If the compressive strength(f’c) of concrete is 21 MPa, what is the modulus of rupture of concrete (in MPa) according to Code? 2.84 The shape of standard specimen used for determining the compressive strength and split-tensile strength of concrete? - Cube - Prism - Beam - Cylinder What compound prevents flash setting? - Gypsum - Calcium silicate hydrate - Dicalcium silicate - Calcium hydroxide What are the characteristics of pozzolan - React with calcium hydroxide - Blended cement - Natural cementitious material - Siliceous/ aluminous material Fineness of cement affects the following - Amount of clinker produced - Rate of hydration - Const of heating - Gypsum requirement What do we call the ability of cement not to undergo large change in volume during hydration? - Exothermic - Fineness - Shrinkage - Soundness What is the basis of the strength of cement? - Based on ASTM C190 - Based on concrete cylindrical test - Based on ASTM C348 - Based on ASTM C109 What is the usual liquid used in determining the specific gravity of cement? - Water - Vinegar - Gasoline - Kerosene The term hydration refers to the chemical reaction between cement, water, and aggregates - True - False What are the compounds that contribute much to the hydration of cement - Tricalcium silicate - Dicalcium silicate  - Tetracalcium aluminoferrite - Tricalcium aluminate What is the standard specific gravity of cement - 3.15 What are the inert and inexpensive material that occupies large percentage volume of concrete? - Aggregates If the rebare spacing is 1 inch (25.44mm), what is the aggregate siz (mm) that will produce the most economical concrete? - ¾” - 1” - ½” - 3/8” What are affected by the shape of aggregates? - Water requirement - Void ratio - Bond area - Durability If the percentage absorption of aggregate is 5%, what is its specific gravity at oven dried condition if the specific gravity at SSD condition is 2.35? - 2.24 Which one is an ideal texture 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 What is the average diameter of aggregates if the fineness modulus is 3.0? - 0.6 Among the choices, which are the physical properties of aggregates? - Specific gravity - Absorption - Grading - Soundness Among the choices which are the mechanical properties of aggregates - Bond - Strength - Toughness - Durability What admixture do we use to advance the time that a structure can be made in service - Accelerator Accelerator can be used with set retarder in concrete mix. - True - False Which admixtures can be used to produce high strength concrete? - Plasticizer - Air-entraining admixture - Accelerator - Silica fume Which are the effects of a set retarder in a concrete mix? - Reduce early strength - Improve workability - Lessen formation of cold joints - Hasten the hardening of concrete What are the effects of plasticizer in a concrete mix? - Increase workability - Increase early strength - Waterproof concrete - Increase water content What should be the acceptable quality of water for a concrete mix? - Purified water - Water free from impurities - Rainwater - Potable water Is the strength of hard concrete affected by the workability of fresh concrete - Yes, to some extent. - No effect at all - Yes, but consolidation can cure it What are the purposes of vibrating fresh concrete? - Proper filling of forms - Provide additional workability - Introduce air entrainment  - Remove entrapped air What are the causes of shrinkage in concrete? - Loss of water due to evaporation - Heat of hydration - Loss of water in hydration - Ove compaction of concrete What are the advantages of ready-mix concrete - No problem in workability - Good quality control - Can be used in congested site - Cheaper What are the different methods in determining the air content of fresh concrete? - Volumetric method - Penetration method - Gravimetric method - Pressure method Chose from the list below which ones are the purpose of curing - Improve concrete surface - Remove impurities from concrete - Prevent water evaporation - Enhanced hydration of concrete What is the term used in coating the inner sides of the mixer with an initial amount to of mortar or cement paste? - Buttering What is another term for shotcrete - Gunite Which one below is the acceptable diameter of pipe for pumping oncrete if the maximum aggregate size is 19 mm? - 40mm - 30mm - 50mm - 60mm A harsh concrete is a fresh concrete that is difficult to mix - True - False What is the term used for fresh concrete pumped underpressure? - Forced concrete - Shotcrete  - Pumpcrete - Batched concrete Among those listed below, which are the measurable properties of fresh concrete? - Workability - Bleeding - Segregation - Air-content What are the possible causes of segregation of fresh concrete? - Gap grading - Improper vibration - Use of river gravel - Incorrect manner of transport What is the property of fresh concrete defining the time required to reach the specified vale of resistance to penetration? - Setting time What are the factors affecting workability of fresh concrete? - Water content - Aggregate grading - Maximum size of aggregates - Air content - Density of aggregates What is the method used to deposit concrete under water? - Tremie What are the acceptable sizes of specimen for compression test of concrete? - 100mm x 200mm cylinders - 6” cubes - 50mm cube - 6” x 12” cylinders What contributes to the strength of concrete - Strength of aggregates - Strength of bond - Strength of cement - Strength of admixture What are some of the mechanical properties of hard concrete? - Modulus of elasticity - Compressive strength - Density - Posson’s ratio Whach one is the acceptable and realistic value of Poisson’s ratio of concrete? - 0.1 - 0.2 - 0.3 - 0.4 Whate is the assumed density of normal weight concrete in kg/cum? - 2400 The concrete stress-strain curve is considered to be elastic up to what percentage of f ’c? - 50 If the compressive strength of normal weight concrete is 28 MPa, which one is the value of the modulus of elasticity, Ec? - 20,000 MPa - 25,800 MPa - 21,538 MPa - 24,870 MPa What is the term used for the long-term deformation of concrete due to application of sustained load? - Creep The compressive strength of concrete used in structural design is obtained on how many days after mixing concrete. - 30 days - 14 days - 28 days - 60 days If the compressive strength(f’c) of concrete is 21 MPa, what is the modulus of rupture of concrete (in MPa) according to Code? - 2.84 The shape of standard specimen used for determining the compressive strength and split-tensile strength of concrete? - Cube - Prism - Beam - Cylinder