Building Materials & Construction interview questions

1. A.blended cement with 15 to 35 percent fly ash under IS 1489, giving lower heat and better durability but slower early strength
2. B.alternate courses of headers and stretchers give the strongest wall, whereas headers and stretchers alternating in each course give better appearance
3. C.grade numbers are 28-day compressive strength in N/mm², with initial setting at least 30 minutes and final setting within 600 minutes
4. D.C3S gives early strength, C2S later strength, C3A causes flash set and heat unless gypsum is added, and C4AF contributes colour

Answer + AI explanation with Pro

1. A.Alkali-aggregate reaction
2. B.OPC grades 33, 43 and 53
3. C.English vs Flemish bond
4. D.Bogue compounds

Answer + AI explanation with Pro

1. A.Bogue compounds — alternate courses of headers and stretchers give the strongest wall, whereas headers and stretchers alternating in each course give better appearance
2. B.Bogue compounds — modular size 190×90×90 mm with minimum compressive strength 3.5 N/mm² and water absorption not over 20 percent after 24 hours
3. C.Bogue compounds — impervious layer at plinth level, such as 1:2:4 concrete with waterproofer or bitumen felt, that stops capillary rise of moisture into walls
4. D.Bogue compounds — C3S gives early strength, C2S later strength, C3A causes flash set and heat unless gypsum is added, and C4AF contributes colour

Answer + AI explanation with Pro

1. A.alternate courses of headers and stretchers give the strongest wall, whereas headers and stretchers alternating in each course give better appearance
2. B.blended cement with 15 to 35 percent fly ash under IS 1489, giving lower heat and better durability but slower early strength
3. C.grade numbers are 28-day compressive strength in N/mm², with initial setting at least 30 minutes and final setting within 600 minutes
4. D.modular size 190×90×90 mm with minimum compressive strength 3.5 N/mm² and water absorption not over 20 percent after 24 hours

Answer + AI explanation with Pro

1. A.Damp-proof course
2. B.Portland pozzolana cement
3. C.Bogue compounds
4. D.OPC grades 33, 43 and 53

Answer + AI explanation with Pro

1. A.OPC grades 33, 43 and 53 — impervious layer at plinth level, such as 1:2:4 concrete with waterproofer or bitumen felt, that stops capillary rise of moisture into walls
2. B.OPC grades 33, 43 and 53 — white salt deposit on masonry from soluble salts in brick or mortar carried to the surface by moisture, rated nil to heavy by IS 3495
3. C.OPC grades 33, 43 and 53 — grade numbers are 28-day compressive strength in N/mm², with initial setting at least 30 minutes and final setting within 600 minutes
4. D.OPC grades 33, 43 and 53 — modular size 190×90×90 mm with minimum compressive strength 3.5 N/mm² and water absorption not over 20 percent after 24 hours

Answer + AI explanation with Pro

1. A.blended cement with 15 to 35 percent fly ash under IS 1489, giving lower heat and better durability but slower early strength
2. B.alternate courses of headers and stretchers give the strongest wall, whereas headers and stretchers alternating in each course give better appearance
3. C.grade numbers are 28-day compressive strength in N/mm², with initial setting at least 30 minutes and final setting within 600 minutes
4. D.white salt deposit on masonry from soluble salts in brick or mortar carried to the surface by moisture, rated nil to heavy by IS 3495

Answer + AI explanation with Pro

1. A.Efflorescence
2. B.Le Chatelier soundness test
3. C.Portland pozzolana cement
4. D.Damp-proof course

Answer + AI explanation with Pro

1. A.Portland pozzolana cement — volume increase of 20 to 30 percent at 4 to 6 percent moisture due to surface tension films, which vanishes when saturated and distorts volume batching
2. B.Portland pozzolana cement — blended cement with 15 to 35 percent fly ash under IS 1489, giving lower heat and better durability but slower early strength
3. C.Portland pozzolana cement — reactive silica in aggregate reacts with cement alkalis to form an expansive gel that cracks concrete years later, avoided by low-alkali cement or pozzolana
4. D.Portland pozzolana cement — white salt deposit on masonry from soluble salts in brick or mortar carried to the surface by moisture, rated nil to heavy by IS 3495

Answer + AI explanation with Pro

1. A.C3S gives early strength, C2S later strength, C3A causes flash set and heat unless gypsum is added, and C4AF contributes colour
2. B.expansion of a cement paste specimen after boiling, limited to 10 mm to guard against delayed expansion from free lime
3. C.modular size 190×90×90 mm with minimum compressive strength 3.5 N/mm² and water absorption not over 20 percent after 24 hours
4. D.alternate courses of headers and stretchers give the strongest wall, whereas headers and stretchers alternating in each course give better appearance

Answer + AI explanation with Pro

1. A.Le Chatelier soundness test
2. B.OPC grades 33, 43 and 53
3. C.Portland pozzolana cement
4. D.English vs Flemish bond

Answer + AI explanation with Pro

1. A.Le Chatelier soundness test — volume increase of 20 to 30 percent at 4 to 6 percent moisture due to surface tension films, which vanishes when saturated and distorts volume batching
2. B.Le Chatelier soundness test — reactive silica in aggregate reacts with cement alkalis to form an expansive gel that cracks concrete years later, avoided by low-alkali cement or pozzolana
3. C.Le Chatelier soundness test — grade numbers are 28-day compressive strength in N/mm², with initial setting at least 30 minutes and final setting within 600 minutes
4. D.Le Chatelier soundness test — expansion of a cement paste specimen after boiling, limited to 10 mm to guard against delayed expansion from free lime

Answer + AI explanation with Pro

1. A.volume increase of 20 to 30 percent at 4 to 6 percent moisture due to surface tension films, which vanishes when saturated and distorts volume batching
2. B.impervious layer at plinth level, such as 1:2:4 concrete with waterproofer or bitumen felt, that stops capillary rise of moisture into walls
3. C.C3S gives early strength, C2S later strength, C3A causes flash set and heat unless gypsum is added, and C4AF contributes colour
4. D.modular size 190×90×90 mm with minimum compressive strength 3.5 N/mm² and water absorption not over 20 percent after 24 hours

Answer + AI explanation with Pro

1. A.Common burnt clay brick
2. B.Bogue compounds
3. C.Damp-proof course
4. D.Portland pozzolana cement

Answer + AI explanation with Pro

1. A.Common burnt clay brick — alternate courses of headers and stretchers give the strongest wall, whereas headers and stretchers alternating in each course give better appearance
2. B.Common burnt clay brick — modular size 190×90×90 mm with minimum compressive strength 3.5 N/mm² and water absorption not over 20 percent after 24 hours
3. C.Common burnt clay brick — expansion of a cement paste specimen after boiling, limited to 10 mm to guard against delayed expansion from free lime
4. D.Common burnt clay brick — blended cement with 15 to 35 percent fly ash under IS 1489, giving lower heat and better durability but slower early strength

Answer + AI explanation with Pro

1. A.grade numbers are 28-day compressive strength in N/mm², with initial setting at least 30 minutes and final setting within 600 minutes
2. B.white salt deposit on masonry from soluble salts in brick or mortar carried to the surface by moisture, rated nil to heavy by IS 3495
3. C.reactive silica in aggregate reacts with cement alkalis to form an expansive gel that cracks concrete years later, avoided by low-alkali cement or pozzolana
4. D.expansion of a cement paste specimen after boiling, limited to 10 mm to guard against delayed expansion from free lime

Answer + AI explanation with Pro

1. A.Bogue compounds
2. B.Efflorescence
3. C.Common burnt clay brick
4. D.Portland pozzolana cement

Answer + AI explanation with Pro

1. A.Efflorescence — white salt deposit on masonry from soluble salts in brick or mortar carried to the surface by moisture, rated nil to heavy by IS 3495
2. B.Efflorescence — reactive silica in aggregate reacts with cement alkalis to form an expansive gel that cracks concrete years later, avoided by low-alkali cement or pozzolana
3. C.Efflorescence — expansion of a cement paste specimen after boiling, limited to 10 mm to guard against delayed expansion from free lime
4. D.Efflorescence — volume increase of 20 to 30 percent at 4 to 6 percent moisture due to surface tension films, which vanishes when saturated and distorts volume batching

Answer + AI explanation with Pro

1. A.expansion of a cement paste specimen after boiling, limited to 10 mm to guard against delayed expansion from free lime
2. B.white salt deposit on masonry from soluble salts in brick or mortar carried to the surface by moisture, rated nil to heavy by IS 3495
3. C.volume increase of 20 to 30 percent at 4 to 6 percent moisture due to surface tension films, which vanishes when saturated and distorts volume batching
4. D.impervious layer at plinth level, such as 1:2:4 concrete with waterproofer or bitumen felt, that stops capillary rise of moisture into walls

Answer + AI explanation with Pro

1. A.Damp-proof course
2. B.Bulking of sand
3. C.OPC grades 33, 43 and 53
4. D.Portland pozzolana cement

Answer + AI explanation with Pro

1. A.Bulking of sand — volume increase of 20 to 30 percent at 4 to 6 percent moisture due to surface tension films, which vanishes when saturated and distorts volume batching
2. B.Bulking of sand — impervious layer at plinth level, such as 1:2:4 concrete with waterproofer or bitumen felt, that stops capillary rise of moisture into walls
3. C.Bulking of sand — C3S gives early strength, C2S later strength, C3A causes flash set and heat unless gypsum is added, and C4AF contributes colour
4. D.Bulking of sand — reactive silica in aggregate reacts with cement alkalis to form an expansive gel that cracks concrete years later, avoided by low-alkali cement or pozzolana

Answer + AI explanation with Pro

1. A.alternate courses of headers and stretchers give the strongest wall, whereas headers and stretchers alternating in each course give better appearance
2. B.C3S gives early strength, C2S later strength, C3A causes flash set and heat unless gypsum is added, and C4AF contributes colour
3. C.modular size 190×90×90 mm with minimum compressive strength 3.5 N/mm² and water absorption not over 20 percent after 24 hours
4. D.white salt deposit on masonry from soluble salts in brick or mortar carried to the surface by moisture, rated nil to heavy by IS 3495

Answer + AI explanation with Pro

1. A.Bogue compounds
2. B.Common burnt clay brick
3. C.English vs Flemish bond
4. D.Efflorescence

Answer + AI explanation with Pro

1. A.English vs Flemish bond — volume increase of 20 to 30 percent at 4 to 6 percent moisture due to surface tension films, which vanishes when saturated and distorts volume batching
2. B.English vs Flemish bond — alternate courses of headers and stretchers give the strongest wall, whereas headers and stretchers alternating in each course give better appearance
3. C.English vs Flemish bond — reactive silica in aggregate reacts with cement alkalis to form an expansive gel that cracks concrete years later, avoided by low-alkali cement or pozzolana
4. D.English vs Flemish bond — expansion of a cement paste specimen after boiling, limited to 10 mm to guard against delayed expansion from free lime

Answer + AI explanation with Pro

1. A.alternate courses of headers and stretchers give the strongest wall, whereas headers and stretchers alternating in each course give better appearance
2. B.volume increase of 20 to 30 percent at 4 to 6 percent moisture due to surface tension films, which vanishes when saturated and distorts volume batching
3. C.impervious layer at plinth level, such as 1:2:4 concrete with waterproofer or bitumen felt, that stops capillary rise of moisture into walls
4. D.blended cement with 15 to 35 percent fly ash under IS 1489, giving lower heat and better durability but slower early strength

Answer + AI explanation with Pro

1. A.Common burnt clay brick
2. B.Bogue compounds
3. C.Alkali-aggregate reaction
4. D.Damp-proof course

Answer + AI explanation with Pro

1. A.Damp-proof course — volume increase of 20 to 30 percent at 4 to 6 percent moisture due to surface tension films, which vanishes when saturated and distorts volume batching
2. B.Damp-proof course — C3S gives early strength, C2S later strength, C3A causes flash set and heat unless gypsum is added, and C4AF contributes colour
3. C.Damp-proof course — modular size 190×90×90 mm with minimum compressive strength 3.5 N/mm² and water absorption not over 20 percent after 24 hours
4. D.Damp-proof course — impervious layer at plinth level, such as 1:2:4 concrete with waterproofer or bitumen felt, that stops capillary rise of moisture into walls

Answer + AI explanation with Pro

1. A.C3S gives early strength, C2S later strength, C3A causes flash set and heat unless gypsum is added, and C4AF contributes colour
2. B.modular size 190×90×90 mm with minimum compressive strength 3.5 N/mm² and water absorption not over 20 percent after 24 hours
3. C.reactive silica in aggregate reacts with cement alkalis to form an expansive gel that cracks concrete years later, avoided by low-alkali cement or pozzolana
4. D.blended cement with 15 to 35 percent fly ash under IS 1489, giving lower heat and better durability but slower early strength

Answer + AI explanation with Pro

1. A.Bogue compounds
2. B.Common burnt clay brick
3. C.Portland pozzolana cement
4. D.Alkali-aggregate reaction

Answer + AI explanation with Pro

1. A.Alkali-aggregate reaction — volume increase of 20 to 30 percent at 4 to 6 percent moisture due to surface tension films, which vanishes when saturated and distorts volume batching
2. B.Alkali-aggregate reaction — reactive silica in aggregate reacts with cement alkalis to form an expansive gel that cracks concrete years later, avoided by low-alkali cement or pozzolana
3. C.Alkali-aggregate reaction — impervious layer at plinth level, such as 1:2:4 concrete with waterproofer or bitumen felt, that stops capillary rise of moisture into walls
4. D.Alkali-aggregate reaction — white salt deposit on masonry from soluble salts in brick or mortar carried to the surface by moisture, rated nil to heavy by IS 3495

Answer + AI explanation with Pro