57. The percentage of the aggregate of FM 26 to be combined with coarse aggregate of FM 68 for obtaining the aggregates of FM 54, is
A.30%
B.40%
C.50%
D.60%

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58.  The impurity of mixing water which affects the setting time and strength of concrete, is
A. sodium sulphates
B. sodium chlorides
C. sodium carbonates and bicarbonates
D. calcium chorides

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59.  The standard sand now a days used in India, is obtained from
A. Jaipur (Rajasthan) ,
B. Jallandhar ( Punjab)
C. Hyderabad (Andhra Pradesh)
D. Ennore (Madras)

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60. An ordinary Portland cement when tested for its fineness, should not leave any residue on IS seive No 9, more than
A.5%
B.10%
C.15%
D.20%

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61.  Pick up the correct statement from the following :
A. Gypsum in cement decreases the setting time
B. The first compound of cement which reacts with water, is C2S
C. Bulking of sand is less when its particles are fine
D. All the above

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62.  Pozzolana cement is used with confidence for construction of
A. darns
B. massive fbundations
C. abutments
D. all the above

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63.  Pick up the correct statement from the following :
A. Insufficient quantity of water makes the concrete mix harsh
B. Insufficient quantity of water makes the concrete unworkable
C. Excess quantity of water makes the concrete segregated
D. All the above

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