1. The relation between modulus of rupture ( fcr ) and cube strength of concrete ( fck ) is
a ) fcr = 0.35 √fk
b ) fcr = 0.7 √fk
c ) fcr = 0.5 √fk
d ) fcr = 1.2 √fk
2. According to IS 1978 , the modulus of rupture in terms of characteristic strength of concrete is given by
a ) 1.2√√fck
b ) 1.25√√fck
c ) 1.30 √fck
d ) 0.7√fck
3. The relation between the split tensile strength ( fct ) and crushing strength ( fck ) for cube
a ) 1.2√√fck
b ) 1.25√√fck
c ) 1.30 √fck
d ) 0.7√fck
4. The young’s modulus of concrete Ec , is
a ) 1000 fck
b ) 5700 √fck
c ) 5700 fck
d ) 1000 √fck
5. Poisson’s ratio for concrete
a ) increase with richer
b) mix decreases richer mix
c ) remains constant
d ) increases with poor mix
6. Fineness modulus of fine aggregate is between
a ) 2-3.5
b ) 3.5-5.0
c ) 5-6.0
d ) 6-7.0
7. If the slump of concrete mix is 60 mm its workability is
a ) low
b ) medium
c ) high
d ) very high
8. Segregation is responsible for
a ) honeycomb concrete
b ) porous layers in concrete
c ) sand streaks in concrete
d ) all of the above
9. If the compaction factor is 0.95, the workability of concrete is
a ) very low
b ) low
c ) medium
d ) high
10. The grade of concrete not recommended by IS : 456 is
a ) M150
b ) M200
c ) M200
d ) M500
11. The durability of concrete is affected by
a ) cider
b ) vinegar
c ) alcohol
d ) both ( a ) and ( b ) above
12. M100 grade of concrete proportion
a ) 1 : 2 : 4 mix
b ) 1 : 3 : 4 mix
c ) 1 : 3 : 6 mix
d ) none of the above
13. Concrete gains strength due to
a ) chemical action of cement with coarse aggregate
b ) hydration of cement
c ) evaporation of water
d ) all of the above
14. Placing of concrete should preferably be done at a temperature of
a ) 10° c
b ) 20°c
c ) 27+-2°c
d ) 32°c
15. Inert material of cement concrete mix is
a ) water
b ) cement
c ) aggregate
d ) all of the above
16. The expansion joints are provided if the length of the concrete exceeds
a ) 20m
b ) 45m
c ) 60m
d ) 75m
17. The compressive strength of concrete determined from 150 mm x 150 mm cylinder as compared to that determined from 150 mm cube is
a ) more
b ) less
c ) equal
d ) none of the above
18. As the size of cube increases the strength of cube
a ) decreases
b ) increases with decreasing rate
c ) increases
d ) decreases with decreasing rate
19. Addition of sugar in concrete results in
a ) increase in setting time by about 4 hr
b ) increase in setting time by about 1 hr
c ) decrease in setting time by about 4 hr
d ) d ecrease in setting time by about 1 hr
20. Later stage strength of cement is caused by
a ) tricalcium silicate
b ) dicalcium silicate
c ) tricalcium aluminate
d ) gypsum aluminate
21. The initial and final setting times for ordinary portland cement are approximately related by
a ) T = 540 + t
b ) T = 270 + t
c ) T = 90 + 1.2t
d ) T = 90 + t
Where T & t are the final and initial setting times.
22. Unsoundness of cement due to magnesia can be determined by
a ) autoclave test
b ) vicat’s needle
c ) Le chatelier’s apparatus
d ) normal consistency
23. White cement is produced in
a ) flyash kiln
b ) coal kiln
c ) oil fired kiln
d ) electrical form kiln
24. The limit of ” loss on ignition ” for ordinary portland cement is
a ) 4 %
b ) 5 %
c ) 6 %
d ) 7 %
25. Slump test in concrete is used for
a ) workability
b ) viscosity
c ) strength
d ) all of the above