151. The top diameter , bottom diameter and the height of a slump mould are
a ) 10 cm , 20 cm , 30 cm
b ) 10 cm , 30 cm , 20 cm
c ) 20 cm , 10 cm , 30 cm
d ) 20 cm , 30 cm , 10 cm
152. In a mix if a desired slump is not obtained , the adjustment for each concrete slump is made by adjusting water content by
a ) 0.25 %
b ) 0.50 %
c ) 0.75 %
d ) 1 %
153. Maximum amount of water content is required if size of the aggregate
a ) round
b ) angular
c ) irregular
d ) none of the above
154. Pick up the incorrect statement from the following :
a ) the bottom and top ends of slump mould are parallel to each other
b ) the axis of the mould is perpendicular to the end faces
c ) the internal surface of the mould is kept clean and free from set cement
d ) the mould is in the form of a frustum of hexagonal pyramid
155. Slump test of concrete is a measure of its
a ) consistency
b ) compressive strength
c ) tensile strength
d ) impact value
156. The amount of slump depends on
a ) workability
b ) aggregate
c ) sand
d ) none of the above
157. In slump test , each layer of concrete compacted by a steel rod 60 cm long and 16 mm diameter for
a ) 20 times
b ) 25 times
c ) 30 times
d ) 40 times
158. If the slump of concrete mix is 60 mm , its workability is
a ) very low
b ) low
c ) medium
d ) high
159. The concrete having a slump of 6.5 cm , is said to be
a ) dry
b ) earth moist
c ) semi – plastic
d ) plastic
160. Slump test is the most widely used field test primarily because
a ) it indicates the behaviour of fresh concrete under action of gravitational forces
b ) of the simplicity of apparatus and test procedure
c ) it measures consistency or wetness of mix
d ) it ensures uniformity among different batches of similar concrete
161. The workability of concrete by slump test is expressed as
b ) mm² / h
a ) mm³ / h
c ) mm / h
d ) mm
162. The slump for beam slab is
a ) 75-150 mm
b ) 15-30 mm
c ) 50-100 mm
d ) all of the above
163. The workability may be defined as the amount of applied work required to compact the concrete to its maximum density . The principle is used in
a ) Vee Bee test
b ) slump test
d ) flow test
c ) compaction factor test
164 , When water cement ratio is increased ; workability
b ) decreases
d ) none of the above
a ) increases
c ) both ( a ) and ( b ) of above
165. A concrete is said to be workable if
a ) it is of uniform colour
b ) it is almost a fluid
c ) it can be easily mixed , placed and compacted
d ) it has a tendency to segregate and bleed
166. Workability of concrete in which low water cement ratio is determined by
a ) tensile strength test
c ) compaction factor test
b ) slump test
d ) flexural strength test
167. Wp and Wf are the weights of a cylinder containing partially compacted and fully compacted concrete . If the compaction factor is 0.95 , the workability of concrete is
a ) extremely low
b ) very low
c ) low
d ) high
168. Pick up the correct statement from the following :
a ) segregation is necessary for a workable concrete
b ) consistency does not affect the workability of concrete
c ) if the slump increases , workability decreases
d ) if the concrete mix is dry , the slump is maximum
e ) none of the above
169. Proper proportioning of concrete , ensures
a ) desired strength and workability
b ) desired durability
c ) water tightness of the structure
d ) resistance to wear
e ) all of the above
170. As the grade of concrete increases the quantity of cement required per cubic metre
a ) increases
b ) decreases
c ) constant
d ) all of the above
171. The grade of concrete M150 means that compressive strength of a 15 cm cube after 28 days , is
a ) 100 kg / cm²
b ) 150 kg / cm²
c ) 200 kg / cm²
d ) 250 kg / cm²
172. A joint positioned so as to separate concrete from adjacent surfaces or into in dividual structural elements that are not in direct physical contact , is known as
a ) contraction joint
b ) expansion joint
c ) construction joint
d ) isolation joint
173. If the engineer – in – charge approves , the 10 cm cubes may be used for the work test of concrete provided maximum nominal size of aggregate , does not exceed
a ) 10 mm
b ) 15 mm
c ) 20 mm
d ) 25 mm
174. Pick up the incorrect statement from the following . While performing preliminary test on concrete
a ) proportions of the material and water should be the same as to be used at the work site
b ) cement should be mixed by hand in order to maintain uniformity
c ) concrete mix should be stored in air – tight containers
d ) concrete ingredients should be kept at a temperature of 37⁰ ± 2 ° C
175. For preparing a test – specimen , it is necessary
a ) to mix cement and fine aggregate by dry hand
b ) to mix coarse aggregates
c ) to mix water to the cement , fine aggregates and coarse aggregates
d ) to oil inter surface of the mould and the base plate , before placing concrete
e) all of the above
