Concrete Technology MCQ – Aggregate MCQ

41. The machine used to determine hardness of stone is called

  1. Dorry’s testing machine
  2. Deval testing machine
  3. Brinell Hardness testing machine
  4. Rockwell hardness testing machine
Answer. a

42. The most undesirable properties of water used for making concrete of mortar are

  1. high concentration of carbonates
  2. high concentration of bicarbonates
  3. high concentration of sulphate and chloride
  4. high concentration of silicates
Answer. c

43. RMC is acronym of

  1. Rapidly mixed concrete
  2. Ready mixed concrete
  3. Readily mix concrete
  4. Recently mixed concrete
Answer. b

44. Test carried out to determine tensile strength of concrete is called

  1. Split test or Brazilian test
  2. Vee-Bee test
  3. Triaxial loading test
  4. Compression test
Answer. a

45. The main undesirable properties of concrete are

  1. Undergoes shrinkage
  2. Requires careful attention during manufacturing, placing and curing
  3. Has lower tensile strength
  4. For equal load, cement members are heavier than steel members
  1. i and iv only
  2. i, ii and iv only
  3. i, ii, ii and iv only
  4. ii, ii and iv only
Answer. b

46. Self-healing concrete is a product

  1. that will be self-compacting after casting
  2. that will biologically produce limestone to heal cracks that appear on the surface of concrete structures
  3. that will conserve the moisture to prevent shrinkage cracks
  4. that will provide ductility to concrete when subjected to tension
Answer. b

47. Which of the following is not a property of high-performance concrete?

  1. High early strength
  2. High abrasion resistant
  3. High modulus of elasticity
  4. High permeability
Answer. d

48. Workability of concrete may be measured by

  1. Slump test
  2. Minimum void method
  3. Maximum density method
  4. Fineness modulus method
Answer. a

49. While testing the compressive strength of cement concrete, the correct conditions (viz temperature, age, humidity and size of the specimen) to be maintained as per IS are

  1. 27 ± 3°C, 28 days, 90% and 15 cm cube
  2. 26 ± 2°C, 28 days, 80% and 15 cm cube
  3. 25 ± 1°C, 14 days, 75% and 10 cm cube
  4. 27 ± 3°C, 7 days, 70% and 10 cm cube
Answer. a

50. For a normal RCC work, the slump of concrete should be in the range of

  1. 25-50 mm
  2. 0-25 mm
  3. 50-125 mm
  4. 80-150 mm
Answer. d