Veer Narmad South Gujarat University 2010 B.E Concrete Technology - 2 ( Sem3 )( Civil ) - Question Paper
B. E. - II
RN-8051
(Sem. Ill) (Civil) Examination May/June - 2010 Concrete Technology
Time : 3 Hours]
[Total Marks : 100
Instructions :
(1)
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Fillup strictly the details of signs on your answer book.
Name of the Examination :
B. E. - 2 (Sem. 3) (Civil)
Name of the Subject:
Concrete Technology
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-Subject Code No. |
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-Section No. (1,2,.....) |
Student's Signature
1&2
(2) Figures to the right indicate full marks.
(3) Assume suitable data, if necessary.
(4) No. I.S. codes are permitted.
1 Complete the following with appropriate words/sentences :
10
(i) The minimum number of specimens required for compressive strength is _.
(ii) Duff Abram's relation for strength of concrete to water
cement ratio is given by_where A and B are
constant and x is water cement ratio.
(iii) For columns and beams _ vibrator is used for
compaction.
(iv) A concrete which can be pushed through a pipe line is called as _.
(v) Tremine is used for _ concreting.
(vi) The relation between Modulus of Elasticity and its characteristic compressive strength is given by_.
(vii) _ and _ are known as alkalies.
(viii)As per IS 456-2000 concrete grades M10 to M20 are in _ concrete group.
(ix) For durable concrete water cement ratio should be _ as far as possible.
(x) American Concrete Institute method is based on_
test of workability.
(a) Enumerate the destructive and non-destructive tests 10 for hardened concrete and describe any one nondestructive test.
(b) Describe the following : 10
(i) Underwater concreting
(ii) Ready mixed concrete.
OR
(a) What is creep? State factors affecting creep. 5
(b) State and explain factors affecting strength of 5 concrete.
(c) Explain alkali aggregate reaction. 5
(d) What is sulphate attack ? State the methods to 5 control sulphate attack.
Design the concrete mix using I.S. method. The 20
requirement of concrete mix is as umder.
(i) Grade of concrete = M30 (RCC)
(ii) Standard Deviation as per I.S. 456-2000
(iii) Maximum size of aggregate = 20 mm (Angular)
(iv) Degree of workability = 0.90 C.F.
(v) Type of Exposure = severe
The test data of material is as under :
(i) Specific gravity of cement = 3.15
(ii) Grade of cement = 43 grade O.P.C.
(iii) Specific gravity of C.A. = 2.85
(iv) Specific gravity of F.A. = 2.60
(v) Grading zone of F.A. = Zone I
Use the data given in table 1 to 7 wherever required.
Also determine the quantity of ingradients required for sag of cement in field if C.A. absorbs 0.5% water and F.A. contains 2% free moisture.
Fill in the blanks: 10
(i) Active group of concrete consists of_and_.
(ii) An argillaceous material contains_and_.
(iii) For fineness test residue should not exceed _
percentage when the cement is sieved through I.S. Sieve No. _ Micron.
(iv) _ set is the abnormal premature hardening
within few minutes of mixing cement with water.
(v) Limiting value of chlorides in water used for concreting is _ ppm.
(vi) Resistance of aggregate to fail by impact is known as
(vii) Fine residue resulting from the combustion of powdered coal and collected by electrostatic precipitator is known as _.
Why admixtures are used in concrete? Explain 6
accelerator admixtures.
5 (a)
(a)
(b) (c)
6 (a)
(b)
(c)
7 (a)
(a)
(b)
OR
Explain how the impurities in water affect the 6
quality of concrete.
Describe with figure consistency test for cement. 5
Explain the sieve analysis test for aggregate. 5
Write short notes on : (any two) 6
(i) Bulking of sand (ii) Sulphur resisting cement
(iii) Fibre reinforced concrete.
Discuss effect of water cement ratio on strength of 5 the concrete.
What are the factors affecting permeability of concrete? 5
What are the advantages of Portland Pozzolana 4
cement?
OR
With flow diagram explain the manufacture of cement. Which are the important points to be considered in rehabilitation of building?
Note : Use data from Table 1-7 for Q. 3
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Table 1: Suggested values of Standard Deviation | ||||||||
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Table 2; Values of Tolerance factor t* | ||||||||||||||
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Table 3: Values of W/C ratio and Compressive strength at 28 days | ||||||||||||||
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Table 4: Minimum Cement Content and Maximum Water Cement Ratio _for Different Exposures__ | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Table 5 : Approximate Entrapped Air content | ||||||||
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Table 6: Approximate Sand and water Content per cubic meter of concrete (W/C=0.60, Workability = 0.08C.T.) forgrade upto M35 | ||||||||||||
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Table 7 : Adjustment of values in water content and sand percentage for other condition | |||||||||||||||||
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RN-8051] 4 [ 100 ]
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Attachment: |
| Earning: Approval pending. |
