Question

1)What is the advantages of gypsum?

a)fire proofing ( X )       b)heat treatment ( )         c)cheap ( )      d)disintegrate in the moisture ( )

2) Where can use the hydraulic lime?

a)bridge ( )               b)building ( X )          c)under sea ( )           d)roads ( )

3) Why alkali oxides (Na2O and K2O ) in cement are harmful ? because they:

a) increase heat of hydration ( )    b)decrease strength of cement ( )   c)react with alkali of aggregates ( )

d)retard the setting time of cement ( )

4)Loss Of Ignition (LOL) indicates _____ or _____ due to prologned or improper storage:

a)prehydation or oxidation ( )      b)prehydration or carbonation ( )   c)oxidation or carbonation ( )

d) non of them ( )

5)which oxide of cement hydrates later than others:

a)SiO₂ ( )             b)Fe₂O₃ ( )         c)K₂O ( )         d) CaO ( )

6)Which components of cement hydrates faster:

a) C₃S ( )              b)C₂S (   )         c)C₃A ( )             d) C₄AF ( )

7) Which rock is not an ingnious rock:

a)shale ( )      b)pumice ( )       c)Quartz ( )     d)basalt ( )

8)Whrere can use the “specific gravity” of aggregates in concrete? To calculate:

a)mix design ( )     b) abrasion resistance ( )    c)compressive strength ( )   d)splitting tensile strength ( )

9)Which test is usefull for determining the workability of “Fiber Reinforced Concrete” ?

a)slump test ( )    b)compacting factor ( )   c)flow table ( )    d) Vebe test ( )

10)Which factor does not have affecting on drying shrinkage?

a)size and shape of structure ( )                                        b)amount of distribution of aggregates ( )                                            c)amount of distribution of reinforcement ( )                  d)humidity of enviroment (   )

11) Which type of shrinkage occur before concrete has set?

a)carbonation shrinkage ( )   b)plastic shrinkage ( )   c)autogenous shrinkage ( ) d)drying shrinkage ( )

12) Which factor is related to Internal Durability ?

a)permeability ( )         b)volume change of aggregates ( )            c)alkali reaction ( )                                             d)attack of industrial liquids ( )

13)Which factor has been affected on workability of concrete?

a)W/C ratio ( )       b)shape of aggregates ( ) c)grading of aggregates ( )   d)all components ( )

14) The chemical reaction between water and cement known as ___________?

a)oxidation (   )    b)hydration (   )     c)carbonation (   )     d)calcination ( )

15) During slaking of lime heat evolves and _______?

a)burn lime ( )     b)volume expands ( )   c) hydration strated ( ) d)react with water ( )

16)Which fault occur due to the improper vibration of concrete?

a)shrinkage ( )   b)compation ( )    c)segregation ( )    d)bleeding ( )

17)What kind of aggregate can reacti with cement?

a)fine aggregates ( )   b)coarse aggregates ( )   c)alkali aggregates ( )    d)methamorphic rocks ( )

18) during the handiling of fresh concrete, what are the most important factors affecting on selection method?

a)econimic ( )        b) maintained the quality of concrete ( )               c)increase strength of concrete ( )    d) a and b ( )

19) __________ in the pure state is white but combined with impurities it may grey, brown or reddish brown?

a)gypsum ( )       b)lime (   )          c)cement ( )      d)sedimantary rocks ( )

20)which type of cement is suitable for concreting in cold wheater ?

a) Ordinary PC( )    b)rapid hardening PC ( )    c)low heat PC ( )    d)sulfate resistance PC ( )

21) which type of cement is used for concerting in sea water?

a)Ordinary PC ( )     b)sulfate resistance PC ( )      c) high aluminum Cement ( )                                                    d) white portland cement ( )

22 ) which type of cement is used in dam constructions?

a) masonary cement( )    b)rapid hardening PC ( )         c)low heat PC ( )     d)sulfate resistance PC ( )

23) Which type of cement is only used for architectural purpose?

a) ground granulated blast furnance slage ( )   b)natural cement ( )     c)wihte portland cement ( ) d)portland pozzolan cement ( )

24)which test is used for low workable concrete?

a) slump test (   )     b)compacting factor ( )    c) flow test ( )      d) kelly ball test ( )

Answer 1

3)C : The alkali oxides react with some aggregates,the products of the alakali aggregate reaction causes disintegration of the concrete.

4)B:loss of ignition is calculated by heating cement sample 900 to 1000°C .A high loss on ignition can indicate prehydration and carbonation.

7)A:shale is a fine grained clastic sedimentary rock composed of mud that is a mix of flakes of clay mineral.

8)A: specific gravity of aggredates is used in calculating Air Voids,voids in mineral aggregate therefore they are useful in mix design

9)B: compaction factor test and inverted slump cone test gives the better results

10)A:Drying shrinkage doesnot depend on the shape and size of the structure

11) B : plastic shrinkage is caused by rapid loss of water from the surface of concrete before it has set.

12)A:concrete durability gets affected when there is a chance of water penetrability into it.

13)D

14)B

15)B : the process of hydration taht is adding of water to calcium oxide

16) C : Denser particles settles down where as lighter particles are on top surface.

17)C: Alkali aggregates reacts with alkali hydroxides in concrete forming hygroscopic gel.

18)B

19)A

20)B

21)B

22)A

23)A

24)A