Modern Construction Materials (noc15-ce05)
NPTEL online course for 14 weeks
July – November, 2015
Details of the questions set for the assignments
Week Week Details
Lectures
Details
1
2
3
4
5
6
7
8
9
10
11
12
13
14
01/07/2015 Chapter : BASICS
07/07/2015
Prologue – Introduction to the course
08/07/2015 Chapter : MICROSTRUCTURE
14/07/2015
Atomic bonding-1, Atomic bonding-2 and
15/07/2015 Chapter : MICROSTRUCTURE
21/07/2015 Structure of solids-2, Structure of solids-3 and
22/07/2015 Chapter : MICRO STRUCTURE
28/07/2015
Development of Microstructure-1
29/07/2015 Chapter : MATERIAL BEHAVIOUR
04/08/2015
Response to Stress-1, Response to Stress-2
05/08/2015 Chapter : MATERIAL BEHAVIOUR
11/08/2015
Failure theories, Fracture Mechanics-1 and
12/08/2015 Chapter : MATERIAL BEHAVIOUR
18/08/2015
Rheology and Thermal properties
19/08/2015 - Chapter : STRUCTURAL MATERIALS
25/08/2015
Wood and wood products-1
26-08-2015 Polymers
01/09/2015
Fibre Reinforced Polymers-1 and
02/09/2015 Metals-1, Metals-2 and Metals-3
08/09/2015
09/09/2015 - Bituminous Materials-1, Bituminous Materilas15/09/2015
2 and Concrete-1
16/09/2015 Concrete-2, Concrete-3 and Concrete-4
22/09/2015
23/09/2015 Concrete-5, Glass and
29/09/2015
Social perception of construction materials
30/09/2015 Water Proofing Materials, Polymer Floor
06/10/2105
Finishes and Anchors
Assignments
Released on or
will be released
on
29-06-2015
Released on
or will be
released on
02-07-2015
05-07-2015 09/07/015
Date of submission
No. of
Questions
22-07-2015
5
25-07-2015
8
13-07-2015
16-07-2015
25-07-2015
7
20-07-2015
22-07-2015
29-07-2015
5
27-07-2015
28-07-2015
05-08-2015
10
02-08-2015
05-08-2015
12-08-2015
12
10-08-2015
13-08-2015
20-08-2015
7
17-08-2015
20-08-2015
27-08-2015
15
24-08-2015
27-08-2015
03-09-2015
8
31-08-2105
03-09-2015
10-09-2015
11
07-09-2015
10-09-2015
17-09-2015
6
14-09-2015
17-09-2015
24-09-2015
10
21-09-2015
24-09-2015
01-10-2015
13
28-09-2015
01-10-2015
08-10-2015
8
125
ASSIGNMENT-1
1. Which of these material is more brittle that aluminium?
a) Structural steel
b) Timber
c) Titanium Alloys
2. Match the Following
1. Nanoscale
A. Material is considered as homogenous
2. Meso scale
B. Molecular structure and chemical composition.
3. Macro scale
C. Material is composed of different, interacting phases
a)
b)
c)
d)
1-C, 2-A, 3-B
1-B, 2-C, 3-A
1-A, 2-B, 3-C
1-A, 2-C, 3-B
3. Consider a cantilever beam of dimensions b, d. The selection criteria for obtaining
required strength at minimum weight is determined by maximizing the term ‘X’. The
term ‘X’ is given by
a) E1/3/ ρ
b) ρ/ σmax1/2
c) σmax1/2 / ρ
d) ρ / E1/3
4. Assuming a normal or Gaussian distribution for the strength of tested samples, what
will be the approximate values of the risk factor k for failure rates of 10%?
1.4
5. Strength tests show that material A has a mean strength of 400 MPa with a
co‐efficient of variation of 12% whereas material B has the same strength with a
co‐efficient of variation of 23%. Material B is marginally cheaper than material A.
Which material would you choose?
A
ASSIGNMENT-2
1. Van de Waals bond can be easily broken by heat.
a) True
b) False
2. In the order of strength of the bonds which amongst the following is true
a) Ionic > Covalent > Hydrogen
b) Covalent > Ionic > Hydrogen
c) Hydrogen > Covalent > Ionic
3. The Condon Morse diagram given below represents which bond
a) Ionic bond
b) Metallic bond
c) Hydrogen bond
4. The boiling point of a material is proportional to the value of
a) Umin
b) R0
c) Ucryst
5. Strongly bonded solids have a higher thermal expansion
a) True
b) False
6. Match the following
1. Metallic Bond
A. High thermal and electrical conductivity
2. Covalent Bond
B. Non-directional
3. Ionic Bond
C. 8-N Rule
a)
b)
c)
d)
1-A, 2-B, 3-C
1-B, 2-A, 3-C
1-A, 2-C, 3-B
1-B, 2-C, 3-A
7. Interlayer cations between the clay causes water adsorption and swelling in clay
a) True
b) False
8. Crystalline structures in which ions are bound directionally lead to random packed
structures
a) True
b) False
ASSIGNMENT-3
1. Which of the following properties are NOT associated with point defects?
a) Strengthening of alloys
b) Causes charge imbalance in clays
c) Increases the lattice binding energy
d) Strain increase in the crystal
2. Different orientation of crystals in a polycrystalline solid causes
a) Discontinuous crystal plane at the grain boundary
b) High energy at the grain boundary
c) Angles of misalignment at the interfacial zones.
d) Only 1 & 3
e) All 1, 2 & 3
3. Name the phenomenon depicted in the image
screw dislocation
4. Fill in the blank spaces: Point defects often occur in pairs. This is to avoid
____________ and also leads to minimisation of ________ within the crystal lattice.
Charge imbalance, strain
5. The image shown below is of ________ plane.
Twinning
6. Which of the following properties are attributed to metallic glasses? (More than one
option can be selected)
a) High resistance to cracking
b) Amorphous
c) Elastic
d) Low work to fracture ratio
7. Match the following
1. Linear Polymers
A. High strength polymers
2. Cross-Linked Polymers
B. High degree of crystallinity
3. Network Polymers
C. Covalent bonds between chains
D. Thermosets
a)
b)
c)
d)
1-B; 2-C,D; 3-A
1-B; 2-D; 3-A,C
1-A; 2-C; 3-B,D
1-C; 2-D; 3-A,B
ASSIGNMENT-4
1. Match the following
1. Gibb’s phase rule at atmospheric pressure
A. 1-2-1 Rule
2. Binary phase diagrams
B. Eutectic
systems
3. Alloys with limited solubility
C. f+p = n+1
4. Rule for finding the fraction of liquid and solid
compositions
D. Lever rule
a)
b)
c)
d)
1-B; 2-C; 3-B; 4-D
1-C; 2-A; 3-B; 4-D
1-C; 2-D; 3-B; 4-A
1-D; 2-C; 3-A; 4-B
2. The crystal growth resulting from crystallisation of melts occurs along preferential
directions like branches called as ___________ and their growth stops when
__________.
a) Branched structure, temperature falls
b) Dendritic structure, cooling rates are slow
c) Branched structure, nucleation is slow
d) Dendritic structure, dendrites meet
3. What is the liquid and solid compositions for the Cu-Ni alloy system shown in the
figure below at 40% Ni and 1300 degree Celsius?
a)
b)
c)
d)
60% and 40%
35% and 65%
100% and 0%
90% and 10%
4. Match the following
1. Lotus leaves
A. Lowers the zeta potential
2. Self-cleaning glass
B. Super hydrophobicity
3. Super-plasticizers
C. Increased wetting and
deflocculating
4. For complete wetting to
occur
D. Spreading force should be positive
a)
b)
c)
d)
1-B; 2-C; 3-A; 4-D
1-A; 2-C; 3-D; 4-B
1-B; 2-C; 3-D; 4-A
1-C; 2-B; 3-A; 4-D
5. The composition for the marked point "G" in the figure shown below is
a)
b)
c)
d)
30% Al2O3 – 20% SiO2 – 50% CaO
80% Al2O3 – 10% SiO2 – 10% CaO
50% Al2O3 – 30% SiO2 – 20% CaO
10% Al2O3 – 20% SiO2 – 70% CaO
ASSIGNMENT-5
1. Rubber has higher Young's modulus than Graphite
a) True
b) False
2. Brittle behaviour is when a material is able to support larger strains before failure
a) True
b) False
3. More the number of slip planes, easier the plastic deformation
a) True
b) False
4. Tensile strength decreases with the increase in temperature
a) True
b) False
5. Ductility increases with increase in strain hardening of the material
a) True
b) False
6. Surface cracks are more effective in causing cracks than internal cracks
a) True
b) False
7. Arrange the following in order of their mechanism w.r.t. primary creep deformation
a)
b)
c)
d)
BAC
ABC
CAB
BCA
8. Match the following
1. Copper has this kind of structure
A. Defects
2. Opposite of strain hardening
B. FCC
3. Phenomenon leading to failure of metal in cold weather
C. Annealing
4. Leads to difference in actual and theoretical value of
strength
D. Ductile to brittle
transition
a)
b)
c)
d)
1-C; 2-B; 3-D; 4-A
1-B; 2-C; 3-A; 4-D
1-B; 2-C; 3-D; 4-A
1-A; 2-C; 3-B; 4-D
9. Permanent deformation of material under load as a function of time is
a) Fracture
b) Annealing
c) Static fatigue
10. The pattern of S-N curve marked "A" in the following is for which material
a) Nylon 6
b) Polymethylmethacrylate
c) Aluminium alloy
ASSIGNMENT-6
1. Shear failure occurs ultimately under hydrostatic compression.
a) True
b) False
2. Failure theories are needed to represent material behaviour under uniaxial loading.
a) True
b) False
3. Concrete exhibits some non-linearity followed by post-peak drop in the stress level.
This phenomenon is called as ______
a) Stress relaxation
b) Strain hardening
c) Stress softening
d) Strain softening
4. The following idealised stress-strain curve represents which behaviour
a)
b)
c)
d)
Rigid –perfect plastic
Elastic-perfectly plastic
Elastic –linear strain hardening
Linear elastic
5. Match the following (If σ1 and σ3 are major and minor principal stresses, σ2 is
intermediate principal stress, Y is yield stress)
1. Octahedral shear stress theory
i) (σ1-σ2)2 + ((σ2-σ3)2 + (σ3-σ1)2 = 2Y2
2. Rankine theory
ii) σ3-σ1 = ±Y
3. Tresca theory
iii) σ1 = ±Y
a)
b)
c)
d)
1-ii, 2-iii, 3-i
1-i, 2-ii, 3-iii
1-ii, 2-I, 3-iii
1-i, 2-iii, 3-ii
6. Von-Mises theory predicts yielding better than Tresca theory because Tresca theory
ignores the effect of intermediate principal stresses.
a) True
b) False
7. Increase in all round confinement will lead to ductile failure.
a) True
b) False
8. According to Mohrs-columb theory more general failure envelope is ____
a) Straight line
b) Parabolic
9. Which of the following statements regarding Linear Elastic Fracture Mechanics
(LEFM) is wrong?
a) Fracture mechanics can be understood by either energy release (G) rate or stress
intensity factor (KI)
b) Stress concentration is inversely proportional to radius at crack tip
c) Stress intensity factor has the units MPa-m1/2
d) The relation between G and KI can be represented as G = KI/E2
(where KI is stress-intensity factor and G is energy release rate)
10. What is stress over the red marked region in the figure given below, if σ is the
applied tensile stress?
a) Lesser than σ
b) More than σ
c) Equal to σ
11. Match the following materials with their failure mechanisms
1. Glass
i) crazing
2. Metals
ii) brittle
3. Polymers
iii) yielding
a) 1-ii, 2-I, 3-iii
b) 1-ii, 2-iii, 3-i
c) 1-ii, 2-iii, 3-iii
12. Match the following
1. Crack blunting
i) crazing
2. Non-linear fracture mechanics
ii) rising resistance curve
3. Stress whitened region
iii) ductile-tearing
4. Fibres
iv) bridging
a)
b)
c)
d)
1-ii, 2-iv, 3-i, 4-iii
1-ii, 2-iii, 3-i, 4-iv
1-ii, 2-iv, 3-i, 4-iii
1-iii, 2-ii, 3-i, 4-iv
ASSIGNMENT-7
1. The components of the Kelvin model are ________ and ____________ elements.
Hookeian, Newtonian
2. What is the SI unit of viscosity?
Poise
3. Viscosity of gas increases with increase in pressure, but for liquids, it decreases.
a) True
b) False
4. Match the following
Material
Property
1. Tomato Ketchup
i. Bingham model
2. Bentonite
ii. Shear thinning
3. Toothpaste
iii. Thixotropic
4. Cornstarch + water
iv. Shear thickening
a)
b)
c)
d)
1-ii; 2-iv, 3-i, 4-iii
1-ii; 2-iii, 3-i, 4-iv
1-iv; 2-iii, 3-ii, 4-i
1-iv; 2-i, 3-ii, 4-iii
5. In earlier times, hard rocks containing ore veins were broken down by heating the
rock face with a wood fire, then quenching with water to induce crack growth. What is
this phenomenon called?
Thermal shock
6. Which of the following statements are true?
a) Invar is a solid solution of Fe-Ni
b) From 0 to 100oC, Invar has zero coefficient of thermal expansion
c) Invar is used as reference in labs for calibration
d) All of the above
7. In Cu-Zn alloy, increasing the composition of copper will increase the thermal
conductivity of the alloy.
a) True
b) False
ASSIGNMENT-8
1. Match the following.
1. Hard wood
2. Soft wood
3. Sap wood
4. Summer wood
5. Inner bark
a)
b)
c)
d)
i) Conifers
ii) Region between bark and wood
iii) Early wood
iv) Deciduous
v) Conducts moisture from root
vi) Smaller cambium cells
vii) Living tissue
1-v, 2-i, 3-v, 4-iii, 5-vi
1-iv, 2-iii, 3-v, 4-vi, 5-vii
1-iv, 2-i, 3-v, 4-vi, 5-vii
1-i, 2-v, 3-i, 4-vi, 5-vii
2. With reference to the structure of wood, which of the statement (or statements) is/are
wrong?
a) Formation of green or black knots depends upon whether the cambium of branch is alive or
dead
b) Apart from longitudinal and transversely oriented cells, the softwood also contains pores &
fibres
c) Cellulose fibrils are bonded together by hydrogen bonding only
d) Lignin is the cementing agent which binds cellulose cells together
e) Wood is strong in the direction of growth
a)
b)
c)
d)
a&c
b, c & e
b&c
a, c & d
3. The number of independent constants require to understand the elastic behaviour of
steel and wood are
a) 2 and 3
b) 2 and 6
c) 2 and 2
d) 2 and 9
4. Specific gravity of a particular wood specie is inversely proportional to the
mechanical properties of that wood. True/False
a) True
b) False
5. Which of the following statement is wrong?
a) Green wood is less vulnerable to fungi attack.
b) Dry timber is recommended for use in structural applications.
c) Seasoning is the removal of moisture from wood with or without causing distortion.
a) A only
b) b & c
c) a & c
d) c only
6. Assertion (A): Strength of wood increases due to seasoning
Reason (R): During seasoning bound water between cells was removed and this leads to
reduced inter atomic distance (r) and subsequently the attractive force
(F=α1α2/r6) increases
a) Both A and R are correct and R is correct explanation for A
b) Both A and R are correct but R is not correct explanation for A
c) A is wrong and R is correct
d) A is correct and R is wrong
7. With reference to the following figure, which of the below given statement (or
statements) is/are wrong?
a)
b)
c)
d)
"O" is called fibre saturation point
"OB" corresponds to the removal bound water
"OA" corresponds to the removal of bound water and shrinkage
In the region of "OB" cell walls are still saturated
8. Wood exhibits differential shrinkage. What is the descending order of various
shrinkage's as per their magnitude
(Refer the following figure. Treat L, R and T as Longitudinal shrinkage, Radial
shrinkage and Tangential Shrinkage)
a)
b)
c)
d)
R>T=L
T>R=L
T>R>L
R>T>L
9. With reference to the Engineering properties of wood, which of the following is not
correctly matched
Engg. Property
Highest in
Lowest in
i) Coefficient of variance
ii) Elastic modulus (E)
iii) Tensile strength
iv) Comp. strength
a)
b)
c)
d)
Work to max. Load
Longitudinal direction
Perpendicular to grain
Perpendicular to grain
Specific gravity
Tangential direction
Parallel to grain
Parallel to grain
iv only
iii &i
iv & iii
iii only
10. Match the following Engg. properties of wood with their failure mechanisms
a) Tensile strength perpendicular to grain
b) Tensile strength parallel to grain
c) Tensile strength in bending
d) Comp. strength Parallel to grain
e) Comp. strength perpendicular to grain
f) Shear strength parallel to grain
a)
b)
c)
d)
a-v, b-ii, c-i, d-iii, e-iv, f-vi
a-iv, b-vi, c-i, d-iii, e-v, f-ii
a-ii, b-v, c-i, d-iii, e-vi, f-iv
a-ii, b-i, c-iii, d-iv, e-v, f-vi
i) Rupture of bottom fibres
ii) Separation of micro-fibrils
iii) Buckling of cell walls
iv) Breaking of secondary bonds
v) Breaking of primary bonds
vi) Collapsing of cells
11. If the modulus of rupture of a wood is 80 MPa in green state, what might be the
modulus of rupture (in MPa) at 12% moisture content?
a) 80
b) 82
c) 100
d) 75
12. Thermal conductivity of wood is directly proportional to the specific gravity of the
wood. True/False?
a) True
b) False
13. Timber can maintain its strength with temperature better than steel and concrete.
The key factor/factors contributing to this is/are:
i) Temperatures beyond 100 0C are necessary for self-ignition.
ii) Formation of char prevents incoming convective heat and protects inner un-burnt timber.
iii) Temperatures beyond 500 0C are necessary for self-ignition in absence of fire.
iv) Failure occurs only when burnt material is lost.
a)
b)
c)
d)
i and iii
ii and iv
iii and ii
iv only
14. Grade of plywood is determined by the type of adhesive used in its manufacturing
process. True/False?
a) True
b) False
15. With reference to the Pre-pressing of veneers in plywood making, which of the
statement is wrong
a) Purpose of pre-pressing is to equally distribute the moisture across the plywood
b) Both heat and pressure are involved
c) By doing this, wraps in end product can be eliminated
d) This should be done after spreading the glue on veneers
ASSIGNMENT-9
1. Polypropylene can be easily melted when compared to Polyethylene
a) True
b) False
2. Which of the following is true when it comes to forming process of FRP
A. Pultrusion
B. Mandrel wrapping
C. Compression moulding
a)
b)
c)
d)
Only A and B are true
Only A and C are true
All are false
All are true
3. Match the following
A. Geomembranes
B. Geotextile
C. Geogrid
D. Geo linear elements
a)
b)
c)
d)
1. Soil reinforcement
2. Anchor for sheet wall structures to soil
3. Tunnel lining
4. Reservoir
A-2, B-3, C-4, D-1
A-3, B-4, C-1, D-2
A-4, B-3, C-2, D-1
A-1, B-4, C-2, D-3
4. In Elastomeric response of thermoplastic polymers, the entire stress is recovered
on removal of strain.
a) True
b) False
5. Polymer is said to be viscous when T<Tg
a) True
b) False
6. Which of the following statement is incorrect for Fiber Reinforced Polymer (FRP)
a) Glass reinforced polymers are strongest and most resistive to deforming forces when
the polymers fibres are perpendicular to the force being exerted.
b) There are no sufficient codes for the use of FRP in strengthening
c) FRP strengthening is expensive
d) Slabs may be strengthened by applying FRP strips at their bottom face
7. Glass fiber is more tensile than steel fiber
a) True
b) False
8. Match the following
A. Glass fibre reinforced polymer
B. Aramid fibre reinforced polymer
C. Carbon fibre reinforced polymer
a)
b)
c)
d)
1. Kevlar
2. Good compressive strength
3. Good heat resistance
A-2, B-3, C-1
A- 3, B-1, C-2
A-1, B-3, C-2
A-3, B-2, C-1
ASSIGNMENT-10
1. Hot working technique of metal forming involves in the contraction of dimensions on
cooling. True/False
a) True
b) False
2. Which of the following statement/statements is/are incorrect regarding metal forming
and joining techniques
a. Exposure of hot metal to air because heavy oxidation film on surface
b. Cold working creates large amounts of dislocations
c. In poly-crystalline metals, cold working produces isotropy
d. Joining material for welding should have properties better than parent metal
e. Filler material melts at lower temperatures in brazing than in soldering
a)
b)
c)
d)
b&d
c&e
b&e
only b
3. Match the following in the context of Dry oxidation
a. Oxide occupies lesser volume than metal
i. Prevents further oxidation
b. Oxide occupies more volume than metal
ii. Shrinkage & cracking
c. Insignificant volume change
iii. Fall off
a) a-i, b-ii, c-iii
b) a-ii, biii, c-i
c) a-i, b-iii, c-ii
d) a-ii, b-i, c-iii
4. In the absence of O2 and presence H2O corrosion occurs. True/False
a) True
b) False
5. The following figure shows the elevation of a RC beam whose bottom surface is
subjected to chloride attack. In this context, identify the four components (C-cathode,
A-anode,
E-electric conductor and I-ionic conductor) of wet corrosion
a)
b)
c)
d)
C-top rebar, A-bottom rebar, E-surrounding concrete, I-stirrups
C-bottom rebar, A-top rebar, E-surrounding concrete, I-stirrups
C-top rebar, A-bottom rebar, E-stirrups, I-surrounding concrete
C-top rebar, A-stirrups, E-surrounding concrete, I-bottom rebar
6. Which of the following statement/statements is/are correct regarding corrosion
prevention
a. Ni, Ti are mostly selected for corrosion resistance as they produce protective oxide films
b. Sacrificial anode can serve large areas
c. Non-cathodic coatings leads to formation of corrosion cells with high anode to cathode
ratio
d. Insufficient dosage of inhibitors results in enhanced corrosion
a)
b)
c)
d)
a, c & d
a, b & d
a&d
b&c
7. Two compositions A & B of pearlitic grey cast iron are given below. Among these two
which composition represents "Ductile iron" and which component is responsible for
ductility?
A - 3.4 wt % of C, 2.5 wt % of Si, 0.01 wt % of P
B - 3.4 wt % of C, 2.5 wt % of Si, 0.01 wt % of P and 0.03 wt % of Mg
a) B and P
b) A and P
c) B and Mg
d) A and C
8. Match the following
a. Carbon steel
i. Carbon content up to 0.25%
b. Mild steel
ii. Presence of elements other than Mn& Si
c. Stainless steel
iii. Carbon content between 0.3% to 0.6%
d. Alloy steel
iv. Ferrite & Fe3C phases
v. Contains Cr & Ni
a)
b)
c)
d)
a-ii, b-i, c-v, d-iii
a-iii, b-i, c-v, d-ii
a-ii, b-i, c-v, d-ii
a-iii, b-i, c-ii, d-v
9. High carbon contents in steel results in good toughness. True/False?
a) True
b) False
10. Which of the following statement is wrong in relation to the micro structure of TMT
bar in Tampering stage?
a)
b)
c)
d)
Core transforms to ferrite & Pearlite
Surface is of tampered matensite
Core is composed of Austenite before this stage
This tampering happens after quenching stage
11. Match the following
a. External Al layers with alternate Bituminous layers i. Sacrificial anode
b. Copper
ii. High strength to weight ratio
c. zinc
iii. Insulated roof
d Titanium
iv. Anti-microbial in nature
v. Anodizing
a)
b)
c)
d)
a-v, b-iv, c-ii, d-i
a-iii, b-iv, c-ii, d-v
a-iii, b-iv, c-i, d-ii
a-v, b-iv, c-i, d-ii
ASSIGNMENT-11
1. Match the following
1 Emusified bitumen A. used as binder in cold mix asphalt
2 Zeolite
B. has high air void content
3 Foamed bitumen
C. reduces the temperature required in hot mix asphalt
4 Cold mix asphalt
D. uses two binders - soft & hard bitumen
5 Warm mix asphalt E. used to increase fluidity in warm mix asphalt
a) 1-C; 2-E; 3-A; 4-B; 5-D
b) 1-C; 2-A; 3-E; 4-D; 5-B
c) 1-E; 2-A; 3-C; 4-B; 5-D
d) 1-A; 2-C; 3-E; 4-D; 5-B
2. Denser grading of aggregates ensures
A. Better stability
B. Better flexibility
C. Better fatigue resistance
D. Prevents rutting
a)
b)
c)
d)
e)
Only A & D are true
Only A & B are true
Only A & C are true
A, C & D are true
All are true
3. Which of the following statements is incorrect?
I Cracking occurs at high temperatures
II Rutting occurs at high viscosity
III Rutting is identified by ditches formed perpendicular to the direction of traffic
IV Cracking can lead to pattern type cracking
a) All of the above
b) I & III only
c) I only
d) II & III only
e) III only
4. Two samples of bitumen, Sample A and Sample B are tested for penetration grade.
Sample A has a penetration value of 10 mm and Sample B has a penetration value of 7
mm. Which sample has better potential for resisting cracking at low temperature?
a) Sample A
b) Sample B
5. Bitumen can be represented as a colloid where _____ are the solid particles in the
form of micelles, dispelled in _____, with _____ forming the interface.
Asphaltenes, oils, resins
6. Which of the following is least favourable condition for asphalt-bitumen bond?
a) Complete wetting of surface of the aggregates by bitumen
b) A thin layer of bitumen surrounds the aggregates
c) Aggregates are moist when bitumen is added
d) Aggregates having rough surfaces are used
ASSIGNMENT-12
1. The following pie chart shows the cement composition. Identify the components A, B,
C, D& E.
a)
b)
c)
d)
A-SiO2, B- CaO, C-Al2O3, D-MgO& E-Fe2O3
A-SiO2, B- CaO, C-Al2O3, D-Fe2O3 & E-MgO
A-CaO, B-SiO2 , C-Al2O3, D-MgO& E-Fe2O3
A-CaO, B-SiO2 , C-Al2O3, D-Fe2O3 & E-MgO
2. With the help of following figure, match the following.
a) Peak I
b) Peak II
c) Peak III
d) T
a)
b)
c)
d)
i. Rapid dissolution of C3S
ii. Ettringite to Monosulfoaluminite transition
iii. Heat of wetting
iv. Dormant period
a-ii, b-i, c-iii, d-iv
a-iii, b-ii, c-i, d-iv
a-iii, b-i, c-ii, d-iv
a-ii, b-iii, c-i, d-iv
3. What is the ascending order of the following parameters related to Hydrated Cement
Paste according to their dimensional range?
A - Aggregation of CSH particles
B - Entrapped air void
C- Spacing between CSH sheets
D- Entrained air void
a)
b)
c)
d)
C-D-B-A
D-C-A-B
D-B-A-C
C-A-D-B
4. For a deck in metro rail project, contractor used M60 concrete. After the
construction, an investigation was carried out under the deck. The investigation
revealed that there are shrinkage cracks. Which of the following might be the problem
related to mix design?
Use of fibres @ dosage of 15kg/m3
Mass replacement of cement with silicafume
Mass replacement of cement with slag
Mass replacement of cement with flyash
5. Every 1% additional air entrainment into the concrete will leads to 10% reduction in
its strength. True/False?
a) True
b) False
6. Which of the following effects are not common between flyash concrete and
silicafume concrete.
A. Increased setting time
B. Reduction in bleeding
C. More requirement of air-entrained admixture for entraining air into concrete
D. Increased water demand
E. Bad fire performance
F. Higher amounts of creep & shrinkage than normal concretes
a)
b)
c)
d)
C, B & D
A, D & E
A, C & F
A, C & E
7. Assertion (A) : Corrosion of steel in concrete results in cracks and spalling.
Reason (R) : Rust has a volume of 2-6 times that of steel and creates expansion in the
concrete.
a) A is false, but R is correct
b) Both A and R are correct, but R is not correct explanation
c) A is correct, but R is false
d) Both A and R are correct, R is correct explanation
8. Which of the following statements are correct in relation to creep and shrinkage of
concrete?
a) Shrkage strains are different in different directions
b) Under the conditions of restrained shrinkage and creep, there will be a reduction in
cracking
c) Creep and shrinkage strains are recoverable
d) To determine the autogeneous shrinkage, the samle should be sealed
a)
b)
c)
d)
a&d
b&d
a, b & c
c, b & d
9. Match the following.
a) Water reducers
i. Early removal of formwork
b) Set-accelerators
ii. Lowers the surface tension of capillary water
c) Steel fibres
iii. Dispersion effect
d) Shrinkage reducing admixtures iv. Anti- washout agent for concretes under water
e) Viscosity Modifying Agent (VMA) v. Improved post peak behaviour
a)
b)
c)
d)
a-iii, b-i, c-v, d-ii, e-iv
a-ii, b-iii, c-iv, d-v, e-i
a-iii, b-iv, c-v, d-ii, e-i
a-ii, b-i, c-v, d-iii, e-iv
10. Match the following in the context of materials used special concretes?
a) Propylene fibres
i. Geopolymer concrete
b) More fines content
ii. High strength concrete
c) Sodium Hydroxide
iii. Aerated concrete
d) Aluminium powder iv.Self compacting concrete
a)
b)
c)
d)
a-ii, b-iv, c-iii, d-i
a-iii, b-iv, c-ii, d-i
a-ii, b-iv, c-i, d-iii
a-iii, b-iv, c-i, d-ii
ASSIGNMENT-13
1. Which of the following is the right sequence during the hydration process?
a) Dormant period, Heat evolution, Steady state, Rapid reaction of alite
b) Heat evolution, Dormant period, Rapid reaction of alite, Steady state
c) Steady state, Dormant period, Heat evolution, Rapid reaction of alite
d) Rapid reaction of alite, Heat evolution, Dormant period, Steady state
2. What happens in flash set reaction in hydration?
a) Aluminates in the absence of gypsum hydrate rapidly to produce calcium-aluminatehydrates
b) Silicates hydrate to produce Calcium-silicate-hydrate gel and calcium hydroxide
c) In the presence of gypsum, ettringite and monosulphate are produced
3. What leads to gel formation of Calcium-Silicate-Hydrate?
a) High covalent/ionic and Van der Waals forces
b) C/S ratio of 1.5 to 2
c) High surface area
4. Indicate what does A, B and C marked in the diagram indicate
a) Portland cement, Natural pozzolan, Class C fly ash
b) Natural pozzolan, Portland cement, Class C fly ash
c) Class C fly ash, Portland cement, Natural pozzolan
5. Which type of grading is ideal for a good concrete mix usually?
a) Gap grading
b) Uniform grading
c) Continuous grading
6. Match the following
A.
Silica
fume
B.
Fly Ash
a)
b)
c)
d)
1.Used as replacement to cement largely in India
2. By-product of iron or steel manufacturing
process
C.
Bentonite 3. Used in conjunction with a superplasticizer
D.
GGBS
4. Used in stabilizing sides of bore holes
A-3, B-1, C-4, D-2
A-2, B-3, C-4, D-1
A-4, B-1, C-2, D-3
A-1, B-4, C-2, D-3
7. Which of the following statements is true w.r.t Chemical admixtures
a) Chemical admixtures affect workability mostly
b) Set controlling chemicals are types of Chemical admixtures
c) Also called Supplementary Cementing materials
a)
b)
c)
d)
All are true
Only A and B are true
Only A and C are true
Only B and C are true
8. What type of shrinkage is the Concrete protected against when freshly laid concrete
is covered by polythene cover?
a) Autogenous shrinkage
b) Thermal shrinkage
c) Plastic shrinkage
d) Drying shrinkage
9. Match the following
A. Sulphate attack
B. Carbonation
C. Alkali-silicate reaction
1. Attacks pore fluid of Concrete
2. Results in formation of gel
3. Destroys cementing effect of Concrete
a) A-3, B-1, C-2
b) A-2, B-3, C-1
c) A-1, B-3, C-2
10. In sulphate attack, the primary products formed are gypsum and ettringite
a) True
b) False
11. Carbonation results in Increase of pH of concrete
a) True
b) False
12. Increase in addition of air entraining admixtures increases the concrete strength
a) True
b) False
13. Moisture and Oxygen both are required for corrosion sustenance
a) True
b) False
ASSIGNMENT-14
1. Damp-proofing is resistance to the passage of water under the hydrostatic pressure.
True/False?
a) True
b) False
2. Which of the following statement/statements is/are correct in relation to the water
proofing
1. Brick bat coba system is flexible
2. Leakage, Seepage and Dampness are distinguished baed on the quantum of flow
3. Seepage refers to continuous flow of water
4. Visible moisture which can be felt by palm is an indication of dampness
a)
b)
c)
d)
1, 2 & 3
2&3
2&4
2, 3 & 4
3. Match the following
1. External waterproofers
2. Internal waterproofers
3. PVC waterstops
4. Polyurethane injection
a. Pore blockers
b. Membranes and coatings
c. Water proofing material for construction joints
d. Arrests the crack
a) 1- a, 2-b, 3-c, 4-d
b) 1- b, 2-a, 3-c, 4-d
c) 1-d , 2-a, 3-c, 4-b
4. Match the following
1. Epoxy flooring
2. PU flooring
3. Densipolished flooring
4. Deck flooring
5. ESD flooring
a)
b)
c)
d)
a. Industrial applications
b. self-levelling
c. Use of Lithium Silicate
d. Dissipates eddy currents developed
e. Anticarbonation floor
1-b, 2-a, 3-c, 4-e, 5-d
1-b, 2-e, 3-a, 4-d, 5-c
1-a, 2-b, 3-c, 4-d, 5-e
1-a, 2-d, 3-c, 4-e, 5-d
5. Aromatic PU floors are used for exterior applications because they have high
resistance to UV radiation. True/False?
a) False
b) True
6. Failure of anchor system due to closely spaced anchors is called......?
a) Concrete breakage
b) Concrete Splitting
7. Identify the incorrect statement in relation to mechanism of anchors
a)
b)
c)
d)
The Bonding force decides the force T2
The diameter of anchor decides the force T2
As the nut gets tightened, the sleeve opens up and friction force develops
Friction decides the tension capacity T1
8. Which of the following is incorrectly matched
a) PROFIS Anchors - a software, which gives size of insert plate for connection between
RCC member and steel; Rebarring with splice - Load transfer by Strut & tie model
b) PROFIS Anchors - a software, which gives anchor force for connection between RCC
member and steel; Rebarring with splice - Load transfer by Strut & tie model
c) PROFIS Rebar - a software, which gives the dowel bars details for connection
between RCC members; Rebarring without splice - Load transferred is equal to
Concrete cone capacity