Sunday, 28 December 2014

Basic civil Engineering Q & A Part 11

The surface joining the static levels in several non-pumping wells penetrating a continuous confined aquifer represents
Water-table surface
Capillary fringe
Piezometric surface of the aquifer
Physical top surface of the aquifer
Answer –Piezometric surface of the aquifer

Critical shear stress of cohesive sediment
Decreases with the void ratio for a given plasticity index
Increases with the plasticity index for a given void ratio
Increases with shear strength for a given clay content
All of the above
Answer –All of the above

EDTA titration method of hardness determination of water sample uses an indicator which combines with hardness-causing divalent cations and forms a coloured complex.The name of the indicator and the colour of the formed complex respectively are
Ferroin and dark blue
Ferroin and wine red
Eriochrome Black T and dark blue
Eriochrome Black T and wine red
Answer — Eriochrome Black T and wine red

The porosity of a soil sample having its void ratio equal to unity would be
33.33%
60.0%
66.66%
75.0%
Answer –60.0%

The porosity of a certain soil sample was found to be 80% and its specific gravity was 2.7 the critical hydraulic gradient will be estimated as
0.34
0.92
1.0
1.5
Answer –0.34

For the determination of shear strength parameters, a and b, of soil in the laboratory,the test to be conducted will be
Triaxial compression test
Sieve analysis
Compaction test
Relative density test
Answer –Triaxial compression test

The field density and field moisture content of a soil can be determined by 1.Core cutter method
2.Sand replacement method
3.Proctor compaction test
4.Modified proctor compaction test
1, 2,3 and 4
1 and 2 only
2 and 3 only
2 and 4 only
Answer — 1 and 2 only

If the whole circle bearing is 315°20′, its quadrantal bearing would be
S 36° 30′ W
N44°40’W
N 57° 24′ W
S 60° 40′ W
Answer –N44°40’W

If the observed fore-bearing of a line xy is 16° 26′, the back bearing of this line is
103° 26′
118° 36′
196° 26′
206° 26′
Answer — 196° 26′

The sub-tense tacheometry method is adopted when the ground is
Flat
Inclined
Undulating
A water-body
Answer — A water-body

In an instrument, the bubble tube with divisions of 1mm and a radius of 0.9m has the sensitivity of
1/2
1/70
1/90
1/900
Answer — 1/900

A contour may be defined as an imaginary line passing through
Points on the longitudinal section
Points of equal elevation
Point of equal local ground slope
Points of transverse section surveys
Answer — Points of equal elevation

A closed contour line with two or more higher contours inside it will represent a
Depression
Hill
Cave
Well
Answer — Hill

Concrete Recycling

The CSI hopes that raising awareness of concrete recycling will promote discussion among all relevant stakeholders and lead to an increase in recycling of concrete. Cement producers can indirectly support this through the work of subsidiaries in the concrete, aggregates and construction industry.
In its report “Recycling Concrete” the CSI argues that the recycling of concrete can reduce natural resource exploitation and waste going to landfill. The report asks for an ultimate goal of “zero landfill” of concrete.
The recovery of concrete falls between standard definitions of reuse and recycling: concrete is broken down into aggregates (granular material), generally to be used in road works, but also as aggregates in new concrete. Recovering concrete has two main advantages: it reduces the use of new virgin aggregate and the associated environmental costs of exploitation and transportation, and it reduces landfill of valuable materials.
While in some countries near full recovery of concrete is achieved, in most parts of the world the potential to recover concrete is overlooked and it ends up as unnecessary waste in landfill. This is generally the result of low public concern, as the waste poses relatively low hazard risks compared to other materials.
The CSI recommends that governments and key stakeholders publicize data on construction and demolition waste and develop reliable and consistent statistics; that they develop economic incentives and legislation to allow infrastructure that promotes concrete recycling (particularly green building schemes); and that they set targets for the use of recycled concrete in both road construction and building industries.

Full Report : http://www.wbcsdcement.org/index.php/key-issues/sustainability-with-concrete/concrete-recycling

Wednesday, 24 December 2014

Properties of Concrete

Concrete’s properties make it the building material of choice for most purposes. The most important features are:
  • Strength and Durability
  • Versatility
  • Low maintenance
  • Affordability
  • Fire-resistance
  • Thermal mass
  • Locally produced and used
  • Albedo effect
  • Low life-cycle CO2 emissions

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Characteristics of Concrete
1
Strength and Durability
  • Used in the majority of buildings, bridges, tunnels and dams for its strength
  • Gains strength over time
  • Not weakened by moisture, mould or pests
  • Concrete structures can withstand natural disasters such as earthquakes and hurricanes
  • Roman buildings over 1,500 years old such as the Coliseum are living examples of the strength and durability of concrete
2
Versatility
  • Concrete is used in buildings, bridges, dams, tunnels, sewerage systems pavements, runways and even roads
3
Low maintenance
  • Concrete, being inert, compact and non-porous, does not attract mould or lose its key properties over time
4
Affordability
  • Compared to other comparable building materials, concrete is less costly to produce and remains extremely affordable
5
Fire-resistance
  • Being naturally fire-resistant concrete forms a highly effective barrier to fire spread



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6
Thermal mass
  • Concrete walls and floors slow the passage of heat moving through, reducing temperature swings
  • This reduces energy needs from heating or air-conditioning, offering year-round energy savings over the life-time of the building
7
Locally produced and used
  • The weight of the material limits concrete sales to within 300km of a plant site
  • Very little cement and concrete is traded and transported internationally
  • This saves significantly on transport emissions of CO2 that would otherwise occur
8
Albedo effect
  • The high "albedo" (reflective qualities) of concrete used in pavements and building walls means more light is reflected and less heat is absorbed, resulting in cooler temperatures
  • This reduces the "urban heat island" effect prevalent in cities today, and hence reduces energy use for e.g. air-conditioning
9
Low life-cycle CO2emissions

  • 80% of a buildings CO2 emissions are generated not by the production of the materials used in its construction, but in the electric utilities of the building over its life-cycle (e.g. lighting, heating, air-conditioning

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Tuesday, 23 December 2014

Basic Civil Q&A Part 10

Here are the next set of Basic Civil Engineering Questions and Answers - 10 .

All these questions and answers are taken from various online sources, to share informations .

If there is any uncertainty/Correction, You can let us know the same .

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The maximum number of unknown forces that can be determined in a concurrent coplanar force system under equilibrium is
2
3
6
1
Answer –2

A uniformly distributed load of length 8 m crosses a simply supported girder of span 20 m. The maximum bending moment at the left quarter-span point occurs when the distance between the point of CG of the total load and mid-span is
2 m
3 m
4 m
0 m
Answer — 2m

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A suspension bridge with a two-hinged stiffening girder is statically
determinate
indeterminate to 1 degree
indeterminate to 2 degree
indeterminate to 3 degree
Answer –determinate


The moment required to rotate the near end of a prismatic beam through unit angle without translation, when the far end is fixed, is
EI/L
2EI/L
3EI/L
4EI/L
Answer –4EI/L

The Muller-Breslau principle in structural analysis is used for
drawing influence line diagram for any force function
superimposition of load effects
writing virtual work equation
None of the above
Answer — drawing influence line diagram for any force function
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The effective throat thickness of a fillet weld depends upon
angle between fusion faces
length of weld
permissible shear stress
type of weld
Answer — angle between fusion faces

When the load line coincides with the centroid of the rivet group, the rivets are subjected to
shear only
tension only
bending only
shear as well as tension
Answer — shear only

A column member of length I which cannot sway has a rigid foundation at its bottom. Its top is held with heavy beams. The effective length of the column is
1.51
1.01
0.81
0.651
Answer — 0.651

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An ISMB 500 is used as a beam in a multistorey construction. From the viewpoint of structural design,it can be considered to be laterally restrained when
the tension flange is laterally restrained
the compression flange is laterally restrained
the web is adequately stiffened
the conditions in both (a) and (c) are met
Answer — the compression flange is laterally restrained

A steel column pinned at both ends has a buckling load of 200 M. If the column is restrained against lateral movement at its mid-height,its buckling load will be
200 kN
283 kN
400 kN
800 kN
Answer –800 kN

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Deflection limitations over beams are imposed because excessive deflection may cause
undesirable twisting and distortion of end connections
problems in drainage system
psychological effect on users
All of the above
Answer –All of the above

For a hydraulically efficient rectangular channel of bed width 4.0 m, the depth of flow is
4 m
0.5 m
1m
2 m
Answer — 2 m

The design flood commonly adopted in India for barrages and minor dams is
Probable maximum flood
A flood of 50-100 years return period
Peak flood
Standard project flood or a 100-year flood, whichever is higher
Answer –Standard project flood or a 100-year flood, whichever is higher
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The Muskingum method of flood routing is a
Form of hydraulic routing of a flood
Form of reservoir routing
Complete numerical solution of St. Venant equations
Hydrological channel routing method
Answer –Hydrological channel routing method

What would be the volume of water stored in a saturated column with a porosity of 0.35 with a cross-sectional area of 1 m square and depth of 3 m ?
2.0 m cube
0.105 m cube
1.05 m cube
3.0 m cube

Answer –1.05 m cube

IS 456-2000 recognises several types of cement for RCC construction.


Wednesday, 17 December 2014

Illustrations of Civil Engineering

Check out some of the wonderful Illustrations of Civil Engineering 

Courtesy - shutterstock 












Tuesday, 16 December 2014

Basic Civil Engineering Q & A - Part 9

Here are the next set of Basic Civil Engineering Questions and Answers - 9 .

All these questions and answers are taken from various online sources, to share informations .

If there is any uncertainty/Correction, You can let us know the same .

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A suspension bridge with a two-hinged stiffening girder is statically
determinate
indeterminate to 1 degree
indeterminate to 2 degree
indeterminate to 3 degree
Answer –determinate

The Muller-Breslau principle in structural analysis is used for
drawing influence line diagram for any force function
superimposition of load effects
writing virtual work equation
None of the above
Answer — drawing influence line diagram for any force functionLIKE US NOW   Acivcrete   - Share it with your friends.

When the effect of wind or earthquake load is taken into account in the design of a riveted connection,the permissible stresses in rivets may be exceeded by
16.66%
33.33%
25%
50%
Answer –25%

The effective throat thickness of a fillet weld depends upon
angle between fusion faces
length of weld
permissible shear stress
type of weld
Answer — angle between fusion faces

When the load line coincides with the centroid of the rivet group, the rivets are subjected to
shear only
tension only
bending only
shear as well as tension
Answer — shear onlyLIKE US NOW   Acivcrete   - Share it with your friends.

A column member of length I which cannot sway has a rigid foundation at its bottom. Its top is held with heavy beams. The effective length of the column is
1.51
1.01
0.81
0.651

Answer — 0.651

What is a SLAB ??
A flat, monolithic piece of stone or concrete used for a floor or roof. There are various forms of reinforced-concrete slabs: one-way slabs cast with supporting beams, ribbed slabs cast with series of joists, two-way ribbed slabs (known as waffle slabs), flat plates reinforced in two or more directions without beams or girders, and flat slabs thickened at column supports with drop panels and/or column capitals. A waffle slab supports loads equally well along both axes and is thus most efficiently used to cover square modules . ( Courtesy - britannica )

Can you name this and when it is used ??



Monday, 1 December 2014

Basic Civil Engineering Q&A 8


Here are the next set of Basic Civil Engineering Questions and Answers - 8 .

All these questions and answers are taken from various online sources, to share informations .

If there is any uncertainty/Correction, You can let us know the same .

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1.The direct stress induces a shear stress of half its intensity on a plane inclined at ........ to the plane of direct stress.

(a) 30 degrees
(b) 45 degrees ( Answer )
(c) 75 degrees
2.What will be the value of maximum shear stress at a point if the major and minor principal stresses on it are 2 MPa and - 2 MPa respectively?

Type your Answer in Comments below 

3.The most suitable type of equipment for compaction of cohesive soils is
smooth-wheeled roller
vibratory roller
sheepsfoot roller
tamper

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4.  For excavating rocks, the most suitable equipment is

dragline
power shovel
clamshell
hoe
Answer — power shovel

5. For heavy vibrating loads in industrial buildings,the roof trusses are provided with

diagonal bracing in the plane of lower chord members
diagonal bracing in the plane of upper chord members
knee bracing
sway bracing
Answer — knee bracing 

6. Which of the following elements of a pitched roof industrial steel building primarily resists lateral load
parallel to the ridge?

Bracing
Purlin
Truss
Column
Answer — Purlin

M-Sand in trends now with degradation of Natural Sand - Your comments on this ??


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