-
০০। 1.S. Sieve Nos. 10 mm and 4.75 mm are geneally used for grading of
- ক) coarse aggregates
- খ) fine aggregates
- গ) neither (a) nor (b)
- ঘ) both (a) and (b)
- ঙ) none of these.
-
০১। 1.S.I. has specified the full strength of concrete after
- ক) 7 days
- খ) 14 days
- গ) 21 days
- ঘ) 28 days
- ঙ) 35 days
-
০২। A concrete having a slump of 6.5 cm, is said to be
- ক) dry
- খ) earth moist
- গ) semi-plastic
- ঘ) plastic
- ঙ) none of these.
-
০৩। A concrete using an air entrained cement
- ক) has strength less than 10% to 15%
- খ) has more resistance to weathering
- গ) is more plastic and workable
- ঘ) is free from segregation and bleeding
- ঙ) all the above.
-
০৪। A construction joint is provided where
- ক) bending moment is small
- খ) shear force is small
- গ) the member is supported by other member
- ঘ) all the above.
-
০৫। A flaky aggregate is said to be elongated if its length is
- ক) equal to the mean size
- খ) twice the mean size
- গ) thrice the mean size
- ঘ) four times the mean size
- ঙ) five times the mean size.
-
০৬। According to I.S. : 456, the number of grades of concrete mixes, is
-
০৭। According to IS : 382-1963, a good aggregate should be
- ক) chemically inert
- খ) sufficiently strong
- গ) hard and durable
- ঘ) all the above.
-
০৮। According to the recommendations of IS : 456-1978, the expansion joints
- ক) are provided where plane changes abruptly
- খ) are provided to ensure minimum resistance
- গ) are supported on separate columns
- ঘ) do not carry reinforcement across them
- ঙ) all the above.
-
০৯। According to Water-Cement Ratio Law, the strength of workable plastic concrete
- ক) depends upon the amount of water used in the mix
- খ) does not depend upon the quality of cement mixed with aggregates
- গ) does not depend upon the quanity of cement mixed with aggregates
- ঘ) all the above.
-
১০। Addition of pozzolana to cement
- ক) decreases workability
- খ) increases strength
- গ) increases heat of hydration
- ঘ) decreases curing time
- ঙ) none of these.
-
১১। Addition of pozzolana to cement causes
- ক) reduction in permeability
- খ) loss of heat of hydration
- গ) reduction in bleeding
- ঘ) increase in curing time
- ঙ) all the above.
-
১২। Addition of pozzolana to ordinary port land cement, causes
- ক) decrease in early strength
- খ) reduction in chemical action with sulphates
- গ) increase in shrinkage
- ঘ) reduction bleeding
- ঙ) all the above.
-
১৩। After casting, an ordinary cement concrete on drying
- ক) expands
- খ) mix
- গ) shrinks
- ঘ) none of these.
-
১৪। Allowable shear strength of concrete, depends upon
- ক) shear strength
- খ) tensile strength
- গ) compressive strength
- ঘ) none of these.
-
১৫। An aggregate is known as cyclopean aggregate if its size is more than
- ক) 4.75 mm
- খ) 30 mm
- গ) 60 mm
- ঘ) 75 mm
- ঙ) 90 mm.
-
১৬। An aggregate is said to be flaky if its least dimension is less than
- ক) 1/5th of mean dimension
- খ) 2/5th of mean dimension
- গ) 3/5th of mean dimension
- ঘ) 4/5th of mean dimension
- ঙ) none of these.
-
১৭। An aggregate is said to be flaky, if its least dimension is less than
- ক) 2/3 mean dimension
- খ) 3/4 mean dimension
- গ) 3/5 mean dimension
- ঘ) 5/8 mean dimension
- ঙ) none of these.
-
১৮। An aggregate which passes through 25 mm I.S. sieve and is retained on 20 mm sieve, is said to be flaky if its least dimension is less than
- ক) 22.5 mm
- খ) 18.5 mm
- গ) 16.5 mm
- ঘ) 15.5 mm
- ঙ) 13.5 mm.
-
১৯। An excess of flaky particles in concrete aggregates
- ক) decreases the workability
- খ) increases the quantity of water and sand
- গ) affects the durability of concrete
- ঘ) more than 15% are not desirable
- ঙ) all the above.