200 Concrete Technology MCQs for GATE & IES: Interactive Quiz with Answers
Question 1: What is the minimum grade of concrete for RCC as per IS 456:2000?
A) M15
B) M20
C) M25
D) M30
IS 456:2000 (Clause 5.4.1) specifies M20 as the minimum grade for reinforced cement concrete (RCC) for durability and strength.
Question 2: Which test is used to determine the workability of fresh concrete?
A) Cube test
B) Slump test
C) Tensile test
D) Compression test
The slump test (IS 1199:1959) measures the workability of fresh concrete by assessing its consistency and flow.
Question 3: What is the standard curing period for concrete as per IS 456:2000?
A) 3 days
B) 7 days
C) 14 days
D) 28 days
IS 456:2000 (Clause 13.5) recommends a minimum curing period of 7 days for normal concrete to achieve adequate strength.
Question 4: Which cement is used for mass concrete structures?
A) OPC 43
B) Rapid-hardening cement
C) Low heat cement
D) PPC
Low heat cement (IS 12600:1989) is used for mass concrete to reduce heat of hydration and prevent thermal cracking.
Question 5: What is the maximum size of coarse aggregate for RCC as per IS 456:2000?
A) 10 mm
B) 20 mm
C) 40 mm
D) 60 mm
IS 456:2000 (Clause 5.3.3) specifies a maximum coarse aggregate size of 20 mm for RCC to ensure proper compaction.
Question 6: Which admixture increases the workability of concrete without adding water?
A) Retarder
B) Accelerator
C) Superplasticizer
D) Air-entraining agent
Superplasticizers (IS 9103:1999) increase workability by reducing water demand, maintaining strength.
Question 7: What is the primary cause of segregation in concrete?
A) High water-cement ratio
B) Low cement content
C) Proper curing
D) High aggregate size
A high water-cement ratio causes segregation, leading to uneven distribution of aggregates (IS 456:2000).
Question 8: Which standard governs the testing of compressive strength of concrete?
A) IS 1199:1959
B) IS 516:1959
C) IS 456:2000
D) IS 2386:1963
IS 516:1959 specifies the cube test for determining the compressive strength of concrete.
Question 9: What is the typical compressive strength of M25 concrete at 28 days?
A) 20 MPa
B) 25 MPa
C) 30 MPa
D) 35 MPa
M25 concrete achieves a compressive strength of 25 MPa at 28 days, per IS 456:2000.
Question 10: Which curing method is most effective for slabs?
A) Steam curing
B) Ponding
C) Formwork retention
D) Chemical curing
Ponding (IS 456:2000) ensures continuous moisture, making it effective for slabs to achieve full hydration.
Question 11: What is the maximum water-cement ratio for M15 concrete in mild exposure?
A) 0.50
B) 0.55
C) 0.60
D) 0.65
IS 456:2000 (Table 5) specifies a maximum water-cement ratio of 0.60 for M15 in mild exposure.
Question 12: Which aggregate property affects concrete’s workability?
A) Specific gravity
B) Shape and texture
C) Silt content
D) Water absorption
Shape and texture (IS 383:2016) influence workability, with angular aggregates reducing flow compared to rounded ones.
Question 13: What is the purpose of air-entraining admixtures?
A) Increase strength
B) Reduce setting time
C) Improve freeze-thaw resistance
D) Enhance workability
Air-entraining agents (IS 9103:1999) introduce air bubbles to improve concrete’s resistance to freeze-thaw cycles.
Question 14: What is the typical slump for pumpable concrete?
A) 25–50 mm
B) 50–100 mm
C) 100–150 mm
D) 150–200 mm
A slump of 100–150 mm (IS 1199:1959) is recommended for pumpable concrete to ensure flow through pipes.
Question 15: Which cement is suitable for high-sulphate environments?
A) OPC 43
B) PPC
C) Sulphate-resisting cement
D) Rapid-hardening cement
Sulphate-resisting cement (IS 12330:1988) is designed to resist sulphate attack in high-sulphate environments.
Question 16: What is the minimum cement content for M20 concrete in moderate exposure?
A) 240 kg/m³
B) 270 kg/m³
C) 300 kg/m³
D) 350 kg/m³
IS 456:2000 (Table 5) specifies a minimum cement content of 300 kg/m³ for M20 in moderate exposure.
Question 17: Which test measures the consistency of fresh concrete?
A) Cube test
B) Vee-Bee test
C) Tensile test
D) Rebound hammer test
The Vee-Bee test (IS 1199:1959) measures the consistency of fresh concrete, especially for low-workability mixes.
Question 18: What is the primary benefit of using fly ash in concrete?
A) Reduces curing time
B) Increases early strength
C) Enhances long-term strength
D) Increases bleeding
Fly ash (IS 1489:2015) enhances long-term strength by forming additional cementitious compounds.
Question 19: What is the maximum allowable silt content in fine aggregates?
A) 1%
B) 3%
C) 5%
D) 8%
IS 383:2016 limits silt content in fine aggregates to 3% to ensure proper bonding and strength.
Question 20: Which curing method is suitable for vertical structures?
A) Ponding
B) Steam curing
C) Formwork retention
D) Shading
Formwork retention (IS 456:2000) retains moisture, making it suitable for vertical structures like columns.
Question 21: What is the typical water-cement ratio for M25 concrete in mild exposure?
A) 0.40
B) 0.45
C) 0.50
D) 0.55
IS 456:2000 (Table 5) specifies a maximum water-cement ratio of 0.50 for M25 in mild exposure.
Question 22: Which standard governs the use of OPC 43 grade cement?
A) IS 8112:2013
B) IS 1489:2015
C) IS 12330:1988
D) IS 456:2000
IS 8112:2013 specifies requirements for OPC 43 grade cement, used for general construction.
Question 23: What is the primary cause of bleeding in concrete?
A) Low water-cement ratio
B) High cement content
C) Excess water
D) Proper compaction
Excess water in the mix causes bleeding, leading to water rising to the surface (IS 456:2000).
Question 24: Which test measures the tensile strength of concrete?
A) Cube test
B) Slump test
C) Split tensile test
D) Rebound hammer test
The split tensile test (IS 5816:1999) measures the tensile strength of concrete using cylindrical specimens.
Question 25: What is the approximate cement requirement for 1 m³ of M20 concrete?
A) 6 bags
B) 8 bags
C) 10 bags
D) 12 bags
For M20, approximately 400 kg of cement (8 bags of 50 kg) is required per m³, per IS 10262:2019.
Question 26: Which curing method accelerates hydration for precast elements?
A) Ponding
B) Steam curing
C) Chemical curing
D) Wet covering
Steam curing (IS 9013:1978) accelerates hydration, achieving high early strength for precast elements.
Question 27: What is the maximum allowable flakiness index for coarse aggregates?
A) 20%
B) 30%
C) 40%
D) 50%
IS 2386:1963 limits the flakiness index to 40% for coarse aggregates to ensure workability and strength.
Question 28: Which admixture reduces the setting time of concrete?
A) Retarder
B) Superplasticizer
C) Air-entraining agent
D) Accelerator
Accelerators (IS 9103:1999) reduce setting time, ideal for rapid construction or cold weather.
Question 29: What is the typical slump for vibrated concrete in beams?
A) 25–50 mm
B) 50–100 mm
C) 100–150 mm
D) 150–200 mm
A slump of 50–100 mm (IS 1199:1959) is suitable for vibrated concrete in beams for adequate workability.
Question 30: Which cement is suitable for cold weather concreting?
A) Low heat cement
B) PPC
C) Rapid-hardening cement
D) Sulphate-resisting cement
Rapid-hardening cement (IS 8041:1990) accelerates hydration, suitable for cold weather.
Question 31: What is the minimum curing period for PPC concrete?
A) 3 days
B) 7 days
C) 10 days
D) 14 days
IS 456:2000 recommends a minimum curing period of 10 days for PPC concrete due to slower hydration.
Question 32: Which test measures the abrasion resistance of aggregates?
A) Soundness test
B) Los Angeles abrasion test
C) Slump test
D) Cube test
The Los Angeles abrasion test (IS 2386:1963, Part 4) assesses the abrasion resistance of aggregates.
Question 33: What is the typical cost range for membrane curing per m²?
A) ₹10–20
B) ₹50–100
C) ₹100–200
D) ₹200–300
Membrane curing costs ₹100–200/m² due to the cost of curing compounds (SciLitpulse blog).
Question 34: Which aggregate size is suitable for thin RCC sections?
A) 10 mm
B) 20 mm
C) 40 mm
D) 60 mm
A 10 mm aggregate size (IS 456:2000) is suitable for thin RCC sections to ensure proper compaction.
Question 35: What is the primary cause of plastic shrinkage cracks?
A) High cement content
B) Rapid surface evaporation
C) Low water-cement ratio
D) Excess curing
Rapid surface evaporation causes plastic shrinkage cracks before hardening (IS 456:2000).
Question 36: Which standard governs the use of PPC?
A) IS 456:2000
B) IS 1489:2015
C) IS 8112:2013
D) IS 12330:1988
IS 1489:2015 specifies requirements for Portland pozzolana cement (PPC) with fly ash or calcined clay.
Question 37: What is the typical water requirement for 1 m³ of M15 concrete?
A) 150 liters
B) 180 liters
C) 200 liters
D) 220 liters
For M15 (W/C = 0.60), approximately 180 liters of water is needed per m³, per IS 10262:2019.
Question 38: Which curing method is cost-effective for large slabs?
A) Steam curing
B) Ponding
C) Chemical curing
D) Formwork retention
Ponding is cost-effective for large slabs, costing ₹50–100/m², ensuring hydration (SciLitpulse blog).
Question 39: What is the maximum allowable chloride content in aggregates?
A) 0.01%
B) 0.04%
C) 0.1%
D) 0.5%
IS 383:2016 limits chloride content in aggregates to 0.04% to prevent corrosion of reinforcement.
Question 40: Which admixture is used for underwater concreting?
A) Retarder
B) Superplasticizer
C) Anti-washout admixture
D) Accelerator
Anti-washout admixtures (IS 9103:1999) prevent cement washout in underwater concreting.
Question 41: What is the typical compressive strength of M30 concrete at 28 days?
A) 20 MPa
B) 25 MPa
C) 30 MPa
D) 35 MPa
M30 concrete achieves a compressive strength of 30 MPa at 28 days, per IS 456:2000.
Question 42: Which test measures the workability of high-flow concrete?
A) Slump test
B) Flow table test
C) Vee-Bee test
D) Compacting factor test
The flow table test (IS 1199:1959) measures workability for high-flow concrete, like self-compacting mixes.
Question 43: What is the maximum allowable silt content in coarse aggregates?
A) 1%
B) 3%
C) 5%
D) 8%
IS 383:2016 limits silt content in coarse aggregates to 1% to ensure proper bonding.
Question 44: Which curing method is best for precast concrete?
A) Ponding
B) Steam curing
C) Chemical curing
D) Wet covering
Steam curing (IS 9013:1978) accelerates hydration for precast concrete, achieving early strength.
Question 45: What is the typical modulus of elasticity for M25 concrete?
A) 20 GPa
B) 25 GPa
C) 30 GPa
D) 35 GPa
The modulus of elasticity for M25 concrete is approximately 25 GPa, per IS 456:2000.
Question 46: Which standard governs the testing of concrete’s permeability?
A) IS 1199:1959
B) IS 3085:1965
C) IS 516:1959
D) IS 456:2000
IS 3085:1965 specifies the permeability test to assess concrete’s resistance to water ingress.
Question 47: What is the approximate sand requirement for 1 m³ of M25 concrete?
A) 0.28 m³
B) 0.49 m³
C) 0.84 m³
D) 1.0 m³
For M25, sand volume is approximately 0.49 m³ per m³, based on IS 10262:2019 mix design.
Question 48: Which admixture enhances concrete’s durability?
A) Retarder
B) Superplasticizer
C) Silica fume
D) Accelerator
Silica fume (IS 15388:2003) enhances durability by reducing permeability and increasing strength.
Question 49: What is the maximum water-cement ratio for M30 concrete in severe exposure?
A) 0.40
B) 0.45
C) 0.50
D) 0.55
IS 456:2000 (Table 5) specifies a maximum water-cement ratio of 0.45 for M30 in severe exposure.
Question 50: Which test measures the soundness of aggregates?
A) Los Angeles abrasion test
B) Soundness test
C) Slump test
D) Cube test
The soundness test (IS 2386:1963, Part 5) assesses aggregates’ resistance to weathering.
Question 51: What is the typical cost range for wet covering curing per m²?
A) ₹200–300
B) ₹500–1,000
C) ₹20–50
D) ₹100–200
Wet covering with hessian costs ₹20–50/m², cost-effective due to reusability (SciLitpulse blog).
Question 52: Which cement is used for high-early-strength concrete?
A) Low heat cement
B) Rapid-hardening cement
C) Sulphate-resisting cement
D) PPC
Rapid-hardening cement (IS 8041:1990) achieves high early strength for precast elements.
Question 53: What is the primary cause of plastic settlement cracks in concrete?
A) High cement content
B) Low water-cement ratio
C) Excess bleeding
D) Proper curing
Excess bleeding causes plastic settlement cracks due to uneven settlement (IS 456:2000).
Question 54: Which standard governs the use of rapid-hardening cement?
A) IS 456:2000
B) IS 8041:1990
C) IS 1489:2015
D) IS 9103:1999
IS 8041:1990 specifies requirements for rapid-hardening cement.
Question 55: What is the maximum clay lump content in aggregates?
A) 1%
B) 3%
C) 5%
D) 8%
IS 2386:1963 limits clay lumps in aggregates to 1% to prevent strength reduction.
Question 56: Which admixture improves concrete’s cohesion?
A) Retarder
B) Superplasticizer
C) Air-entraining agent
D) Accelerator
Air-entraining agents (IS 9103:1999) improve cohesion, reducing segregation and bleeding.
Question 57: What is the CO2 reduction by using 30% GGBS in concrete?
A) 10–15%
B) 20–25%
C) 30–35%
D) 40–45%
Using 30% GGBS (IS 16714:2018) reduces CO2 emissions by 20–25%.
Question 58: What is the typical cement content for 1 m³ of M35 concrete?
A) 7 bags
B) 9 bags
C) 11 bags
D) 13 bags
For M35, approximately 550 kg of cement (11 bags of 50 kg) is required per m³, per IS 10262:2019.
Question 59: Which curing method is least suitable for precast elements?
A) Steam curing
B) Water curing
C) Shading
D) Chemical curing
Shading is least suitable for precast elements as it does not accelerate hydration (IS 456:2000).
Question 60: What is the typical modulus of elasticity for M30 concrete?
A) 20 GPa
B) 25 GPa
C) 28 GPa
D) 35 GPa
The modulus of elasticity for M30 concrete is approximately 28 GPa, per IS 456:2000.
Question 61: What is the maximum allowable flakiness index for aggregates in RCC?
A) 20%
B) 30%
C) 40%
D) 50%
IS 2386:1963 limits the flakiness index to 40% for aggregates in RCC.
Question 62: Which admixture reduces bleeding in concrete?
A) Retarder
B) Superplasticizer
C) Air-entraining agent
D) Accelerator
Air-entraining agents (IS 9103:1999) reduce bleeding by improving cohesion in the mix.
Question 63: What is the typical water-cement ratio for M35 concrete in moderate exposure?
A) 0.40
B) 0.45
C) 0.50
D) 0.55
IS 456:2000 (Table 5) specifies a maximum water-cement ratio of 0.45 for M35 in moderate exposure.
Question 64: Which test measures the impact resistance of aggregates?
A) Soundness test
B) Aggregate impact test
C) Los Angeles abrasion test
D) Slump test
The aggregate impact test (IS 2386:1963, Part 4) measures the impact resistance of aggregates.
Question 65: What is the typical cost range for ponding curing per m²?
A) ₹10–20
B) ₹50–100
C) ₹100–200
D) ₹200–300
Ponding curing costs ₹50–100/m² due to water and labor requirements (SciLitpulse blog).
Question 66: Which cement is suitable for marine structures?
A) OPC 43
B) PPC
C) Sulphate-resisting cement
D) Rapid-hardening cement
Sulphate-resisting cement (IS 12330:1988) is suitable for marine structures to resist sulphate and chloride attack.
Question 67: What is the typical slump for concrete in slabs?
A) 25–50 mm
B) 50–100 mm
C) 100–150 mm
D) 150–200 mm
A slump of 100–150 mm (IS 1199:1959) is suitable for concrete in slabs for adequate workability.
Question 68: Which factor increases concrete’s strength?
A) High water-cement ratio
B) Low cement content
C) Proper compaction
D) High aggregate size
Proper compaction (IS 456:2000) increases concrete’s strength by reducing voids.
Question 69: What is the maximum allowable water absorption for coarse aggregates in RCC?
A) 1%
B) 2%
C) 3%
D) 5%
IS 2386:1963 limits water absorption of coarse aggregates to 2% for RCC to ensure quality.
Question 70: Which curing method is best for pavements?
A) Ponding
B) Steam curing
C) Chemical curing
D) Shading
Chemical curing (IS 8142:1976) is effective for pavements, retaining moisture in large areas.
Question 71: What is the typical cement content for 1 m³ of M50 concrete?
A) 8 bags
B) 10 bags
C) 12 bags
D) 14 bags
For M50, approximately 600 kg of cement (12 bags of 50 kg) is required per m³, per IS 10262:2019.
Question 72: Which test measures the durability of concrete under freeze-thaw conditions?
A) Slump test
B) Cube test
C) Freeze-thaw test
D) Rebound hammer test
The freeze-thaw test assesses concrete’s durability under freeze-thaw cycles, referenced in IS codes.
Question 73: What is the primary cause of alkali-silica reaction in concrete?
A) High cement content
B) Reactive aggregates
C) Low water-cement ratio
D) Excess curing
Reactive aggregates cause alkali-silica reaction, leading to expansion and cracking (IS 456:2000).
Question 74: Which standard governs the use of fly ash in concrete?
A) IS 456:2000
B) IS 1489:2015
C) IS 9103:1999
D) IS 8112:2013
IS 1489:2015 specifies requirements for Portland pozzolana cement with fly ash.
Question 75: What is the typical water requirement for 1 m³ of M45 concrete?
A) 150 liters
B) 170 liters
C) 190 liters
D) 210 liters
For M45 (W/C = 0.38–0.42), approximately 190 liters of water is needed per m³, per IS 10262:2019.
Question 76: Which curing method is most effective for retaining moisture in footings?
A) Ponding
B) Steam curing
C) Wet covering
D) Shading
Ponding (IS 456:2000) is effective for footings, ensuring continuous moisture.
Question 77: What is the typical tensile strength of M45 concrete?
A) 3.5 MPa
B) 4.0 MPa
C) 4.5 MPa
D) 5.0 MPa
The tensile strength of M45 concrete is approximately 4.5 MPa, per IS 5816:1999.
Question 78: What is the maximum allowable chloride content in fine aggregates?
A) 0.01%
B) 0.04%
C) 0.1%
D) 0.5%
IS 383:2016 limits chloride content in fine aggregates to 0.04% to prevent corrosion.
Question 79: Which admixture is used to improve workability in hot weather?
A) Retarder
B) Superplasticizer
C) Air-entraining agent
D) Accelerator
Superplasticizers (IS 9103:1999) improve workability in hot weather by reducing water demand.
Question 80: What is the CO2 reduction by using 50% GGBS in concrete?
A) 20–25%
B) 30–35%
C) 40–45%
D) 50–55%
Using 50% GGBS (IS 16714:2018) reduces CO2 emissions by 40–45%.
Question 81: What is the maximum allowable aggregate size for plain cement concrete?
A) 20 mm
B) 40 mm
C) 60 mm
D) 80 mm
IS 456:2000 (Clause 5.3.3) specifies a maximum aggregate size of 40 mm for plain cement concrete to ensure workability.
Question 82: Which test assesses the bond strength between concrete and steel?
A) Pull-out test
B) Slump test
C) Cube test
D) Rebound hammer test
The pull-out test (IS 2770:1967) measures the bond strength between concrete and reinforcement.
Question 83: What is the typical compressive strength of M40 concrete at 28 days?
A) 30 MPa
B) 35 MPa
C) 40 MPa
D) 45 MPa
M40 concrete achieves a compressive strength of 40 MPa at 28 days, per IS 456:2000.
Question 84: Which admixture is used to delay setting time in hot weather?
A) Accelerator
B) Retarder
C) Superplasticizer
D) Air-entraining agent
Retarders (IS 9103:1999) delay setting time, suitable for hot weather concreting.
Question 85: What is the typical water-cement ratio for M40 concrete in severe exposure?
A) 0.40
B) 0.45
C) 0.50
D) 0.55
IS 456:2000 (Table 5) specifies a maximum water-cement ratio of 0.40 for M40 in severe exposure.
Question 86: Which test measures the workability of low-slump concrete?
A) Slump test
B) Flow table test
C) Compacting factor test
D) Cube test
The compacting factor test (IS 1199:1959) measures workability for low-slump concrete mixes.
Question 87: What is the typical cost range for chemical curing per m²?
A) ₹20–50
B) ₹50–100
C) ₹100–200
D) ₹200–300
Chemical curing costs ₹100–200/m² due to curing compound expenses (SciLitpulse blog).
Question 88: Which cement is used for low-temperature concreting?
A) Low heat cement
B) Rapid-hardening cement
C) PPC
D) Sulphate-resisting cement
Rapid-hardening cement (IS 8041:1990) is used for low-temperature concreting to accelerate setting.
Question 89: What is the primary cause of thermal cracks in concrete?
A) Low cement content
B) High heat of hydration
C) Proper curing
D) Low water-cement ratio
High heat of hydration causes thermal cracks, especially in mass concrete (IS 456:2000).
Question 90: Which standard governs the use of low heat cement?
A) IS 456:2000
B) IS 12600:1989
C) IS 1489:2015
D) IS 8112:2013
IS 12600:1989 specifies requirements for low heat cement for mass concreting.
Question 91: What is the typical sand requirement for 1 m³ of M30 concrete?
A) 0.28 m³
B) 0.47 m³
C) 0.84 m³
D) 1.0 m³
For M30, sand volume is approximately 0.47 m³ per m³, based on IS 10262:2019 mix design.
Question 92: Which test measures the strength of hardened concrete non-destructively?
A) Slump test
B) Rebound hammer test
C) Flow table test
D) Vee-Bee test
The rebound hammer test (IS 13311:1992, Part 2) assesses hardened concrete’s strength non-destructively.
Question 93: What is the typical tensile strength of M30 concrete?
A) 2.5 MPa
B) 3.0 MPa
C) 3.8 MPa
D) 4.5 MPa
The tensile strength of M30 concrete is approximately 3.8 MPa, per IS 5816:1999.
Question 94: Which curing method is suitable for hot weather?
A) Steam curing
B) Wet covering
C) Ponding
D) Formwork retention
Wet covering (IS 456:2000) retains moisture, suitable for hot weather concreting.
Question 95: What is the maximum allowable elongation index for aggregates?
A) 20%
B) 30%
C) 40%
D) 50%
IS 2386:1963 limits the elongation index to 40% for aggregates to ensure workability.
Question 96: Which admixture is used for high-strength concrete?
A) Retarder
B) Silica fume
C) Air-entraining agent
D) Accelerator
Silica fume (IS 15388:2003) enhances strength and reduces permeability in high-strength concrete.
Question 97: What is the typical water requirement for 1 m³ of M50 concrete?
A) 150 liters
B) 180 liters
C) 200 liters
D) 220 liters
For M50 (W/C = 0.35–0.40), approximately 180 liters of water is needed per m³, per IS 10262:2019.
Question 98: Which test measures the specific gravity of aggregates?
A) Specific gravity test
B) Los Angeles abrasion test
C) Soundness test
D) Slump test
The specific gravity test (IS 2386:1963, Part 3) measures the density of aggregates relative to water.
Question 99: What is the typical modulus of elasticity for M40 concrete?
A) 25 GPa
B) 28 GPa
C) 31 GPa
D) 35 GPa
The modulus of elasticity for M40 concrete is approximately 31 GPa, per IS 456:2000.
Question 100: Which curing method is best for columns?
A) Ponding
B) Formwork retention
C) Steam curing
D) Chemical curing
Formwork retention (IS 456:2000) is best for columns, retaining moisture effectively.
Question 101: What is the maximum organic matter content in aggregates?
A) 0.5%
B) 1%
C) 2%
D) 3%
IS 2386:1963 limits organic matter in aggregates to 0.5% to prevent strength reduction.
Question 102: Which standard governs the testing of concrete’s tensile strength?
A) IS 516:1959
B) IS 5816:1999
C) IS 1199:1959
D) IS 3085:1965
IS 5816:1999 specifies the split tensile test for determining concrete’s tensile strength.
Question 103: What is the typical slump for concrete in columns?
A) 25–50 mm
B) 50–100 mm
C) 100–150 mm
D) 150–200 mm
A slump of 100–150 mm (IS 1199:1959) is suitable for columns to ensure proper placement.
Question 104: Which cement is suitable for high-performance concrete?
A) Low heat cement
B) OPC 53
C) PPC
D) Sulphate-resisting cement
OPC 53 (IS 12269:2013) is used for high-performance concrete due to its high strength.
Question 105: What is the primary cause of thermal cracking in concrete?
A) High heat of hydration
B) Low water-cement ratio
C) Proper curing
D) High aggregate size
High heat of hydration causes thermal cracking, especially in mass concrete (IS 456:2000).
Question 106: Which standard governs the use of OPC 53 grade cement?
A) IS 1489:2015
B) IS 12269:2013
C) IS 12600:1989
D) IS 9103:1999
IS 12269:2013 specifies requirements for OPC 53 grade cement, used for high-strength applications.
Question 107: What is the typical cement content for 1 m³ of M45 concrete?
A) 8 bags
B) 10 bags
C) 12 bags
D) 14 bags
For M45, approximately 600 kg of cement (12 bags of 50 kg) is required per m³, per IS 10262:2019.
Question 108: Which test measures the workability of low-slump concrete?
A) Slump test
B) Vee-Bee test
C) Flow table test
D) Compacting factor test
The Vee-Bee test (IS 1199:1959) is suitable for measuring the workability of low-slump concrete.
Question 109: What is the maximum allowable water absorption for fine aggregates?
A) 1%
B) 2%
C) 3%
D) 5%
IS 2386:1963 limits water absorption of fine aggregates to 2% to ensure quality.
Question 110: Which curing method is best for high-rise structures?
A) Ponding
B) Wet covering
C) Steam curing
D) Shading
Wet covering (IS 456:2000) is practical for high-rise structures to maintain moisture.
Question 111: What is the typical tensile strength of M50 concrete?
A) 3.5 MPa
B) 4.0 MPa
C) 4.7 MPa
D) 5.0 MPa
The tensile strength of M50 concrete is approximately 4.7 MPa, per IS 5816:1999.
Question 112: Which admixture is used to reduce permeability in concrete?
A) Retarder
B) Silica fume
C) Air-entraining agent
D) Accelerator
Silica fume (IS 15388:2003) reduces permeability by densifying the concrete matrix.
Question 113: What is the typical cost range for chemical curing per m²?
A) ₹10–20
B) ₹50–100
C) ₹100–200
D) ₹200–300
Chemical curing costs ₹100–200/m² due to the cost of curing compounds (SciLitpulse blog).
Question 114: Which standard governs the testing of aggregates?
A) IS 456:2000
B) IS 2386:1963
C) IS 516:1959
D) IS 1199:1959
IS 2386:1963 specifies tests for aggregates, including flakiness, elongation, and soundness.
Question 115: What is the maximum allowable sulphate content in aggregates?
A) 0.1%
B) 0.5%
C) 1.0%
D) 2.0%
IS 383:2016 limits sulphate content in aggregates to 0.1% to prevent chemical attack.
Question 116: Which curing method is suitable for mass concrete?
A) Ponding
B) Steam curing
C) Wet covering
D) Shading
Ponding (IS 456:2000) is suitable for mass concrete to control heat of hydration.
Question 117: What is the typical compressive strength of M50 concrete at 28 days?
A) 40 MPa
B) 45 MPa
C) 50 MPa
D) 55 MPa
M50 concrete achieves a compressive strength of 50 MPa at 28 days, per IS 456:2000.
Question 118: Which test measures the water absorption of aggregates?
A) Flakiness test
B) Water absorption test
C) Soundness test
D) Abrasion test
The water absorption test (IS 2386:1963, Part 3) measures the water absorption of aggregates.
Question 119: What is the primary benefit of using superplasticizers in concrete?
A) Reduces curing time
B) Increases workability
C) Increases bleeding
D) Reduces strength
Superplasticizers (IS 9103:1999) increase workability without adding water, maintaining strength.
Question 120: What is the typical modulus of elasticity for M50 concrete?
A) 25 GPa
B) 30 GPa
C) 35 GPa
D) 40 GPa
The modulus of elasticity for M50 concrete is approximately 35 GPa, per IS 456:2000.
Question 121: What is the maximum allowable water-cement ratio for M50 concrete in severe exposure?
A) 0.35
B) 0.40
C) 0.45
D) 0.50
IS 456:2000 (Table 5) specifies a maximum water-cement ratio of 0.40 for M50 in severe exposure.
Question 122: Which test measures the consistency of self-compacting concrete?
A) Slump test
B) Slump flow test
C) Vee-Bee test
D) Compacting factor test
The slump flow test (IS 1199:1959) measures the consistency of self-compacting concrete.
Question 123: Which cement is suitable for emergency repairs?
A) Low heat cement
B) Rapid-hardening cement
C) PPC
D) Sulphate-resisting cement
Rapid-hardening cement (IS 8041:1990) is used for emergency repairs due to its quick strength gain.
Question 124: What is the primary cause of honeycombing in concrete?
A) Poor compaction
B) High water-cement ratio
C) Proper curing
D) High cement content
Poor compaction (IS 456:2000) causes honeycombing, leading to voids in concrete.
Question 125: What is the typical sand requirement for 1 m³ of M40 concrete?
A) 0.30 m³
B) 0.45 m³
C) 0.80 m³
D) 1.0 m³
For M40, sand volume is approximately 0.45 m³ per m³, based on IS 10262:2019 mix design.
Question 126: Which standard governs the use of admixtures in concrete?
A) IS 456:2000
B) IS 9103:1999
C) IS 1489:2015
D) IS 12269:2013
IS 9103:1999 specifies requirements for chemical admixtures in concrete.
Question 127: What is the typical water requirement for 1 m³ of M40 concrete?
A) 150 liters
B) 170 liters
C) 190 liters
D) 210 liters
For M40 (W/C = 0.40–0.45), approximately 190 liters of water is needed per m³, per IS 10262:2019.
Question 128: Which curing method is suitable for precast beams?
A) Ponding
B) Steam curing
C) Wet covering
D) Shading
Steam curing (IS 9013:1978) is suitable for precast beams to achieve early strength.
Question 129: What is the typical compressive strength of M60 concrete at 28 days?
A) 50 MPa
B) 55 MPa
C) 60 MPa
D) 65 MPa
M60 concrete achieves a compressive strength of 60 MPa at 28 days, per IS 456:2000.
Question 130: Which test measures the crushing strength of aggregates?
A) Soundness test
B) Aggregate crushing value test
C) Flakiness test
D) Water absorption test
The aggregate crushing value test (IS 2386:1963, Part 4) measures the crushing strength of aggregates.
Question 131: What is the typical tensile strength of M60 concrete?
A) 4.0 MPa
B) 4.5 MPa
C) 5.0 MPa
D) 5.5 MPa
The tensile strength of M60 concrete is approximately 5.0 MPa, per IS 5816:1999.
Question 132: Which admixture is used for mass concreting?
A) Retarder
B) Low-range water reducer
C) Air-entraining agent
D) Accelerator
Low-range water reducers (IS 9103:1999) control heat of hydration in mass concreting.
Question 133: What is the typical cost range for wet covering curing per m²?
A) ₹100–200
B) ₹20–50
C) ₹50–100
D) ₹200–300
Wet covering with hessian costs ₹20–50/m², cost-effective due to reusability (SciLitpulse blog).
Question 134: Which standard governs the testing of concrete’s workability?
A) IS 516:1959
B) IS 1199:1959
C) IS 5816:1999
D) IS 2386:1963
IS 1199:1959 specifies tests like slump and Vee-Bee for concrete workability.
Question 135: What is the maximum allowable clay content in fine aggregates?
A) 1%
B) 3%
C) 5%
D) 8%
IS 2386:1963 limits clay content in fine aggregates to 1% to ensure bonding.
Question 136: Which curing method is suitable for underwater structures?
A) Ponding
B) Formwork retention
C) Steam curing
D) Shading
Formwork retention (IS 456:2000) ensures curing for underwater structures by retaining moisture.
Question 137: What is the typical modulus of elasticity for M60 concrete?
A) 30 GPa
B) 35 GPa
C) 38 GPa
D) 40 GPa
The modulus of elasticity for M60 concrete is approximately 38 GPa, per IS 456:2000.
Question 138: Which admixture is used for high-early-strength concrete?
A) Retarder
B) Accelerator
C) Air-entraining agent
D) Superplasticizer
Accelerators (IS 9103:1999) are used for high-early-strength concrete to speed up hydration.
Question 139: What is the typical cost range for ponding curing per m²?
A) ₹10–20
B) ₹50–100
C) ₹100–200
D) ₹200–300
Ponding curing costs ₹50–100/m² due to water and labor requirements (SciLitpulse blog).
Question 140: Which test measures the durability of aggregates under sulphate attack?
A) Soundness test
B) Abrasion test
C) Flakiness test
D) Water absorption test
The soundness test (IS 2386:1963, Part 5) measures aggregates’ durability under sulphate attack.
Question 141: What is the typical water-cement ratio for M60 concrete in severe exposure?
A) 0.35
B) 0.40
C) 0.45
D) 0.50
IS 456:2000 (Table 5) specifies a maximum water-cement ratio of 0.35 for M60 in severe exposure.
Question 142: Which cement is suitable for mass concrete dams?
A) Low heat cement
B) Rapid-hardening cement
C) OPC 43
D) PPC
Low heat cement (IS 12600:1989) is used for mass concrete dams to minimize thermal cracking.
Question 143: What is the primary cause of scaling in concrete?
A) Freeze-thaw cycles
B) High cement content
C) Low water-cement ratio
D) Proper curing
Freeze-thaw cycles cause scaling, leading to surface flaking (IS 456:2000).
Question 144: Which test measures the flowability of self-compacting concrete?
A) Slump test
B) Slump flow test
C) Vee-Bee test
D) Compacting factor test
The slump flow test (IS 1199:1959) measures the flowability of self-compacting concrete.
Question 145: What is the typical sand requirement for 1 m³ of M50 concrete?
A) 0.30 m³
B) 0.43 m³
C) 0.80 m³
D) 1.0 m³
For M50, sand volume is approximately 0.43 m³ per m³, based on IS 10262:2019 mix design.
Question 146: Which standard governs the use of silica fume in concrete?
A) IS 456:2000
B) IS 15388:2003
C) IS 9103:1999
D) IS 12269:2013
IS 15388:2003 specifies requirements for silica fume in concrete for enhanced durability.
Question 147: What is the typical water requirement for 1 m³ of M60 concrete?
A) 150 liters
B) 170 liters
C) 190 liters
D) 210 liters
For M60 (W/C = 0.32–0.35), approximately 190 liters of water is needed per m³, per IS 10262:2019.
Question 148: Which curing method is suitable for bridge decks?
A) Steam curing
B) Chemical curing
C) Wet covering
D) Shading
Chemical curing (IS 8142:1976) is suitable for bridge decks to retain moisture in large areas.
Question 149: What is the typical tensile strength of M70 concrete?
A) 4.5 MPa
B) 5.0 MPa
C) 5.2 MPa
D) 5.5 MPa
The tensile strength of M70 concrete is approximately 5.2 MPa, per IS 5816:1999.
Question 150: Which test measures the permeability of concrete?
A) Slump test
B) Permeability test
C) Cube test
D) Vee-Bee test
The permeability test (IS 3085:1965) measures concrete’s resistance to water ingress.
Question 151: What is the maximum allowable organic matter content in fine aggregates?
A) 0.5%
B) 1%
C) 2%
D) 3%
IS 2386:1963 limits organic matter in fine aggregates to 0.5% to prevent strength reduction.
Question 152: Which admixture is used for cold weather concreting?
A) Retarder
B) Accelerator
C) Air-entraining agent
D) Superplasticizer
Accelerators (IS 9103:1999) speed up hydration for cold weather concreting.
Question 153: What is the typical cost range for steam curing per m²?
A) ₹50–100
B) ₹100–200
C) ₹500–1,000
D) ₹1,000–1,500
Steam curing costs ₹500–1,000/m² due to energy and equipment requirements (SciLitpulse blog).
Question 154: Which standard governs the use of sulphate-resisting cement?
A) IS 456:2000
B) IS 12330:1988
C) IS 1489:2015
D) IS 9103:1999
IS 12330:1988 specifies requirements for sulphate-resisting cement.
Question 155: What is the typical sand requirement for 1 m³ of M60 concrete?
A) 0.30 m³
B) 0.42 m³
C) 0.80 m³
D) 1.0 m³
For M60, sand volume is approximately 0.42 m³ per m³, based on IS 10262:2019 mix design.
Question 156: Which curing method is suitable for precast slabs?
A) Ponding
B) Steam curing
C) Wet covering
D) Shading
Steam curing (IS 9013:1978) is suitable for precast slabs to achieve early strength.
Question 157: What is the typical compressive strength of M70 concrete at 28 days?
A) 60 MPa
B) 65 MPa
C) 70 MPa
D) 75 MPa
M70 concrete achieves a compressive strength of 70 MPa at 28 days, per IS 456:2000.
Question 158: Which test measures the flakiness of aggregates?
A) Flakiness test
B) Soundness test
C) Abrasion test
D) Water absorption test
The flakiness test (IS 2386:1963, Part 1) measures the flakiness of aggregates.
Question 159: What is the primary benefit of using air-entraining agents in concrete?
A) Increases early strength
B) Improves freeze-thaw resistance
C) Reduces curing time
D) Increases bleeding
Air-entraining agents (IS 9103:1999) improve freeze-thaw resistance by introducing air bubbles.
Question 160: What is the typical modulus of elasticity for M70 concrete?
A) 35 GPa
B) 38 GPa
C) 40 GPa
D) 45 GPa
The modulus of elasticity for M70 concrete is approximately 40 GPa, per IS 456:2000.
Question 161: What is the maximum allowable water-cement ratio for M70 concrete in severe exposure?
A) 0.35
B) 0.40
C) 0.45
D) 0.50
IS 456:2000 (Table 5) specifies a maximum water-cement ratio of 0.35 for M70 in severe exposure.
Question 162: Which cement is suitable for high-rise buildings?
A) Low heat cement
B) OPC 53
C) PPC
D) Sulphate-resisting cement
OPC 53 (IS 12269:2013) is used for high-rise buildings due to its high strength.
Question 163: What is the primary cause of efflorescence in concrete?
A) Soluble salts
B) High cement content
C) Low water-cement ratio
D) Proper curing
Soluble salts cause efflorescence, leading to white deposits on concrete surfaces (IS 456:2000).
Question 164: Which test measures the elongation of aggregates?
A) Elongation test
B) Soundness test
C) Abrasion test
D) Water absorption test
The elongation test (IS 2386:1963, Part 1) measures the elongation of aggregates.
Question 165: What is the typical sand requirement for 1 m³ of M70 concrete?
A) 0.30 m³
B) 0.41 m³
C) 0.80 m³
D) 1.0 m³
For M70, sand volume is approximately 0.41 m³ per m³, based on IS 10262:2019 mix design.
Question 166: Which standard governs the use of GGBS in concrete?
A) IS 456:2000
B) IS 16714:2018
C) IS 9103:1999
D) IS 12269:2013
IS 16714:2018 specifies requirements for ground granulated blast furnace slag (GGBS) in concrete.
Question 167: What is the typical water requirement for 1 m³ of M70 concrete?
A) 150 liters
B) 170 liters
C) 190 liters
D) 210 liters
For M70 (W/C = 0.32–0.35), approximately 190 liters of water is needed per m³, per IS 10262:2019.
Question 168: Which curing method is least effective for high-rise structures?
A) Wet covering
B) Chemical curing
C) Shading
D) Formwork retention
Shading (IS 456:2000) is least effective for high-rise structures as it only reduces evaporation, not retains moisture.
Question 169: What is the maximum allowable flakiness index for aggregates?
A) 20%
B) 30%
C) 40%
D) 50%
IS 2386:1963 limits the flakiness index to 40% for aggregates to ensure workability and strength.
Question 170: Which admixture improves the durability of concrete in sulphate-rich environments?
A) Retarder
B) GGBS
C) Air-entraining agent
D) Accelerator
GGBS (IS 16714:2018) enhances sulphate resistance, improving concrete durability.
Question 171: What is the typical cement content for 1 m³ of M60 concrete?
A) 8 bags
B) 10 bags
C) 12 bags
D) 14 bags
For M60, approximately 600 kg of cement (12 bags of 50 kg) is required per m³, per IS 10262:2019.
Question 172: Which test measures the bond strength of concrete?
A) Pull-out test
B) Slump test
C) Cube test
D) Vee-Bee test
The pull-out test (IS 2770:1967) measures the bond strength between concrete and reinforcement.
Question 173: What is the typical cost range for formwork retention curing per m²?
A) ₹10–20
B) ₹50–100
C) ₹100–200
D) ₹200–300
Formwork retention curing costs ₹50–100/m² due to minimal additional labor (SciLitpulse blog).
Question 174: Which standard governs the use of rapid-hardening cement?
A) IS 456:2000
B) IS 8041:1990
C) IS 1489:2015
D) IS 12269:2013
IS 8041:1990 specifies requirements for rapid-hardening cement for quick strength gain.
Question 175: What is the maximum allowable chloride content in aggregates?
A) 0.04%
B) 0.1%
C) 0.5%
D) 1.0%
IS 383:2016 limits chloride content in aggregates to 0.04% to prevent corrosion of reinforcement.
Question 176: Which curing method is suitable for pavements?
A) Steam curing
B) Chemical curing
C) Wet covering
D) Shading
Chemical curing (IS 8142:1976) is suitable for pavements to retain moisture in large areas.
Question 177: What is the typical tensile strength of M80 concrete?
A) 4.5 MPa
B) 5.0 MPa
C) 5.5 MPa
D) 6.0 MPa
The tensile strength of M80 concrete is approximately 5.5 MPa, per IS 5816:1999.
Question 178: Which test measures the abrasion resistance of aggregates?
A) Abrasion test
B) Soundness test
C) Flakiness test
D) Water absorption test
The abrasion test (IS 2386:1963, Part 4) measures the abrasion resistance of aggregates.
Question 179: What is the primary benefit of using fly ash in concrete?
A) Increases early strength
B) Improves long-term durability
C) Reduces curing time
D) Increases bleeding
Fly ash (IS 3812:2013) improves long-term durability by reducing permeability and enhancing strength.
Question 180: What is the typical modulus of elasticity for M80 concrete?
A) 35 GPa
B) 40 GPa
C) 42 GPa
D) 45 GPa
The modulus of elasticity for M80 concrete is approximately 42 GPa, per IS 456:2000.
Question 181: What is the maximum allowable water-cement ratio for M80 concrete in severe exposure?
A) 0.35
B) 0.40
C) 0.45
D) 0.50
IS 456:2000 (Table 5) specifies a maximum water-cement ratio of 0.35 for M80 in severe exposure.
Question 182: Which cement is suitable for marine structures?
A) Low heat cement
B) Sulphate-resisting cement
C) OPC 43
D) Rapid-hardening cement
Sulphate-resisting cement (IS 12330:1988) is used for marine structures to resist sulphate attack.
Question 183: What is the primary cause of segregation in concrete?
A) Improper mixing
B) Low water-cement ratio
C) Proper curing
D) High cement content
Improper mixing (IS 456:2000) causes segregation, leading to separation of aggregates and cement paste.
Question 184: Which test measures the compressive strength of concrete cores?
A) Slump test
B) Core test
C) Vee-Bee test
D) Flow table test
The core test (IS 516:1959) measures the compressive strength of concrete cores from existing structures.
Question 185: What is the typical sand requirement for 1 m³ of M80 concrete?
A) 0.30 m³
B) 0.40 m³
C) 0.80 m³
D) 1.0 m³
For M80, sand volume is approximately 0.40 m³ per m³, based on IS 10262:2019 mix design.
Question 186: Which standard governs the use of fly ash in concrete?
A) IS 456:2000
B) IS 3812:2013
C) IS 9103:1999
D) IS 12269:2013
IS 3812:2013 specifies requirements for fly ash in concrete for improved durability.
Question 187: What is the typical water requirement for 1 m³ of M80 concrete?
A) 150 liters
B) 170 liters
C) 190 liters
D) 210 liters
For M80 (W/C = 0.30–0.35), approximately 190 liters of water is needed per m³, per IS 10262:2019.
Question 188: Which curing method is suitable for tunnel linings?
A) Ponding
B) Formwork retention
C) Steam curing
D) Shading
Formwork retention (IS 456:2000) is suitable for tunnel linings to retain moisture in confined spaces.
Question 189: What is the typical compressive strength of M80 concrete at 28 days?
A) 70 MPa
B) 75 MPa
C) 80 MPa
D) 85 MPa
M80 concrete achieves a compressive strength of 80 MPa at 28 days, per IS 456:2000.
Question 190: Which test measures the impact resistance of aggregates?
A) Aggregate impact test
B) Soundness test
C) Flakiness test
D) Water absorption test
The aggregate impact test (IS 2386:1963, Part 4) measures the impact resistance of aggregates.
Question 191: What is the typical tensile strength of M90 concrete?
A) 5.0 MPa
B) 5.5 MPa
C) 5.8 MPa
D) 6.0 MPa
The tensile strength of M90 concrete is approximately 5.8 MPa, per IS 5816:1999.
Question 192: Which admixture is used for underwater concreting?
A) Retarder
B) Anti-washout admixture
C) Air-entraining agent
D) Accelerator
Anti-washout admixtures (IS 9103:1999) prevent segregation in underwater concreting.
Question 193: What is the typical cost range for chemical curing per m²?
A) ₹10–20
B) ₹50–100
C) ₹100–200
D) ₹200–300
Chemical curing costs ₹100–200/m² due to the cost of curing compounds (SciLitpulse blog).
Question 194: Which standard governs the testing of concrete’s bond strength?
A) IS 516:1959
B) IS 2770:1967
C) IS 1199:1959
D) IS 3085:1965
IS 2770:1967 specifies the pull-out test for testing concrete’s bond strength.
Question 195: What is the maximum allowable silt content in fine aggregates?
A) 1%
B) 3%
C) 5%
D) 8%
IS 2386:1963 limits silt content in fine aggregates to 3% to ensure proper bonding.
Question 196: Which curing method is suitable for high-performance concrete?
A) Shading
B) Wet covering
C) Steam curing
D) Formwork retention
Wet covering (IS 456:2000) is suitable for high-performance concrete to ensure adequate hydration.
Question 197: What is the typical compressive strength of M90 concrete at 28 days?
A) 80 MPa
B) 85 MPa
C) 90 MPa
D) 95 MPa
M90 concrete achieves a compressive strength of 90 MPa at 28 days, per IS 456:2000.
Question 198: Which test measures the workability of high-slump concrete?
A) Slump test
B) Vee-Bee test
C) Compacting factor test
D) Pull-out test
The slump test (IS 1199:1959) is suitable for measuring the workability of high-slump concrete.
Question 199: What is the primary benefit of using silica fume in concrete?
A) Increases early strength
B) Reduces permeability
C) Reduces curing time
D) Increases bleeding
Silica fume (IS 15388:2003) reduces permeability, enhancing concrete durability.
Question 200: What is the typical modulus of elasticity for M90 concrete?
A) 40 GPa
B) 42 GPa
C) 44 GPa
D) 46 GPa
The modulus of elasticity for M90 concrete is approximately 44 GPa, per IS 456:2000.
Report Card
Total Questions Attempted: 0
Correct Answers: 0
Wrong Answers: 0
Percentage: 0%
0 Comments