22305 Concrete Technology Important MSBTE Exam Questions

22305 Concrete Technology Important MSBTE Exam Questions

22305 IMP

1. Attempt any FIVE of the following: 10
a) List four physical properties of OPC.
b) Define bulking of sand.
c) State Duff Abraham’s water-cement ratio law.
d) Name four methods / affecting concrete mix design.
e) In sequence, Draw & write concreting operations.
f) State two purposes of using accelerating admixtures in the concrete.
g) State two uses of low-heat cement.
h) Define the hydration of cement.

 

2. Attempt any THREE of the following: 12
a) Explain the method to determine the initial and final setting time of cement.
b) Classify the aggregate based on its size and shape.
c) A sand sample has a fineness modulus of 1.95. Whether this sand can be used for concrete? Explain the procedure to bring the fineness modulus within the required permissible limits. State its\ importance.
d) Explain the procedure to determine the fineness of cement by the dry sieving method. State it IS a requirement.
e) List four substances in water having deleterious effects. State their effects on concrete.
f) Explain the determination of bulking of fine aggregate with a neat sketch.
g) Explain the procedure to find the specific gravity of the fine aggregate in the laboratory
h) Explain the flakiness index and elongation index in detail.

3. Attempt any THREE of the following: 12
a) Suggest the compaction factor for the following degree of workability.
(i) Medium
(ii) High
(iii) Very low
(iv) Low
b) Illustrate the effect of coarse aggregates' properties on concrete compressive strength.
c) Explain the procedure for measurement of the workability of fresh concrete using the slump cone test.
d) Explain the necessity of supervision for concreting operations (any four)
e) Suggest the degree of workability in terms of a slump for the following:
(i) Pavements using pavers.
(ii) Canal lining.
(iii) Heavily reinforced sections
(iv) In-situ piling
f) Explain two causes of each
(i) Segregation
(ii) Bleeding of concrete.
g) Explain two factors affecting the properties of hardened concrete.
h) Calculate the quantity of water to be added for costing cubes in the laboratory by 12.5 kg cement, if the w/c ratio is 0.45.
i) Suggest the minimum grade of concrete for the following exposure conditions.
(i) RCC work
(ii) Water retaining structure.
(iii) Seawater construction
(iv) Prestressed concrete.
4. Attempt any THREE of the following: 12
a) Explain the importance and Effect of the water/cement ratio in the concrete mix.
b) Write four objectives of concrete mix design.
c) Describe four characteristics of ready-mix concrete.
d) Explain four effects of hot and cold weather on concrete.
e) Explain & Write two advantages and two disadvantages of vacuum de-watered concrete floors.
f) Define the following special types of concretes with one use.
(i) Vacuum concrete
(ii) Fiber-reinforced concrete.
(iii) High-performance concrete
(iv) Self-compacting concrete.

 

5. Attempt any TWO of the following: 12
a) Explain the laboratory procedure to determine the compressive strength of concrete cubes as per IS-516-1959 with reference to the following points:
(i) preparation of test specimen
(ii) Procedure of testing
(iii) Interpretation of results.
b) Explain the rebound hammer test procedure and show the relationship between compressive strength and rebound number with the hammer horizontally and vertically on a dry and wet surface of the concrete.
c) Explain the ultrasonic pulse velocity test and techniques for measuring pulse velocity through concrete.
d) Write one suitability of each of the different six non-destructive tests.

6. Attempt any TWO of the following: 12
a) Write four requirements of suitable formwork and draw a sketch showing cross-section of formwork for an L-shaped column.
b) Suggest one type of material for waterproofing for the following situations:
(i) Rising dampness in the building
(ii) Leakages in the dam
(iii) Concrete continuously in wet or damp conditions.
(iv) Leakages in the lavatory, bathroom and kitchen floor
(v) Cracks on plastered surface
(vi) Cracks on the roof surface
c) Suggest the type of joints in concrete when it is likely to increase in volume due to temperature change. Explain it and draw its neat sketch.
d) Explain the significance of batching, compaction and curing of concrete.
e) Draw neat and labelled sketches of the following:
(i) Plan of column formwork.
(ii) Expansion joint with the load transfer device.
f) (i) Suggest the appropriate method of waterproofing used for the following construction.
1) Basements of buildings.
2) Swimming pool.
3) Water tank.
(ii) Suggest the appropriate method of transportation of concrete used for construction in the following situation. *
1) Concreting in hilly areas.
2) Concreting of a highrise building.
3) Concreting underwater.
g) Classify the methods of curing concrete with a detailed explanation of any one method.
h) State the requirement of good formwork and state the stripping time of formwork as per IS 456-2000.
(i) Slab
(ii) Beam
(iii) Column