Saturday 18 October 2014

Syllabus for Civil Engineering (CE) == >

 GATE 2015 paper Pattern for Civil Engineering
 Engineering Mathematics Engineering Mathematics will have 13% of total marks weigh
 General Aptitude  General Aptitude will have 15% of total marks weigh
 Subject questions Subject questions will have rest 72% of total marks weigh


           Syllabus for Civil Engineering (CE)  == >



ENGINEERING MATHEMATICS = =>

Linear Algebra: Matrix algebra, Systems of linear equations, Eigen values and eigenvectors. 
Calculus: Functions of single variable, Limit, continuity and differentiability, Mean value 
theorems, Evaluation of definite and improper integrals, Partial derivatives, Total derivative, 
Maxima and minima, Gradient, Divergence and Curl, Vector identities, Directional derivatives, 
Line, Surface and Volume integrals, Stokes, Gauss and Green’s theorems. 
Differential equations: First order equations (linear and nonlinear), Higher order linear 
differential equations with constant coefficients, Cauchy’s and Euler’s equations, Initial and 
boundary value problems, Laplace transforms, Solutions of one dimensional heat and wave 
equations and Laplace equation. 
Complex variables: Analytic functions, Cauchy’s integral theorem, Taylor and Laurent series. 
Probability and Statistics: Definitions of probability and sampling theorems, Conditional 
probability, Mean, median, mode and standard deviation, Random variables, Poisson, Normal 
and Binomial distributions. 
Numerical Methods: Numerical solutions of linear and non-linear algebraic equations 
Integration by trapezoidal and Simpson’s rule, single and multi-step methods for differential 
equations. 

STRUCTURAL ENGINEERING = =>

Mechanics: == >

Bending moment and shear force in statically determinate beams. Simple stress and 
strain relationship: Stress and strain in two dimensions, principal stresses, stress transformation, 
Mohr’s circle. Simple bending theory, flexural and shear stresses, unsymmetrical bending, shear 
centre. Thin walled pressure vessels, uniform torsion, buckling of column, combined and direct 
bending stresses. 

Structural Analysis: = =>

Analysis of statically determinate trusses, arches, beams, cables and 
frames, displacements in statically determinate structures and analysis of statically indeterminate 
structures by force/ energy methods, analysis by displacement methods (slope deflection and 
moment distribution methods), influence lines for determinate and indeterminate structures. 
Basic concepts of matrix methods of structural analysis. 

Concrete Structures == >

 Concrete Technology- properties of concrete, basics of mix design. 
Concrete design- basic working stress and limit state design concepts, analysis of ultimate load 
capacity and design of members subjected to flexure, shear, compression and torsion by limit 
state methods. Basic elements of prestressed concrete, analysis of beam sections at transfer and 
service loads. Steel Structures: Analysis and design of tension and compression members, beams and beam- 
columns, column bases. Connections- simple and eccentric, beam–column connections, plate 
girders and trusses. Plastic analysis of beams and frames. 

GEOTECHNICAL ENGINEERING = =>

Soil Mechanics: == >

Origin of soils, soil classification, three-phase system, fundamental definitions, 
relationship and interrelationships, permeability &seepage, effective stress principle, 
consolidation, compaction, shear strength. 


Foundation Engineering:  == >

Sub-surface investigations- scope, drilling bore holes, sampling, 
penetration tests, plate load test. Earth pressure theories, effect of water table, layered soils. 
Stability of slopes-infinite slopes, finite slopes. Foundation types-foundation design 
requirements. Shallow foundations-bearing capacity, effect of shape, water table and other 
factors, stress distribution, settlement analysis in sands & clays. Deep foundations–pile types, 
dynamic & static formulae, load capacity of piles in sands & clays, negative skin friction. 

WATER RESOURCES ENGINEERING  = =>

Fluid Mechanics and Hydraulics:= = = > 

Properties of fluids, principle of conservation of mass, 
momentum, energy and corresponding equations, potential flow, applications of momentum and 
Bernoulli’s equation, laminar and turbulent flow, flow in pipes, pipe networks. Concept of 
boundary layer and its growth. Uniform flow, critical flow and gradually varied flow in channels, 
specific energy concept, hydraulic jump. Forces on immersed bodies, flow measurements in 
channels, tanks and pipes. Dimensional analysis and hydraulic modeling. Kinematics of flow, 
velocity triangles and specific speed of pumps and turbines. 

Hydrology: == >

Hydrologic cycle, rainfall, evaporation, infiltration, stage discharge relationships, 
unit hydrographs, flood estimation, reservoir capacity, reservoir and channel routing. Well 
hydraulics. 
Irrigation: == >

Duty, delta, estimation of evapo-transpiration. Crop water requirements. Design of: 
lined and unlined canals, waterways, head works, gravity dams and spillways. Design of weirs 
on permeable foundation. Types of irrigation system, irrigation methods. Water logging and 
drainage, sodic soils. 

ENVIRONMENTAL ENGINEERING  = =>

Water requirements:= = =>

Quality standards, basic unit processes and operations for water 
treatment. Drinking water standards, water requirements, basic unit operations and unit processes 
for surface water treatment, distribution of water. Sewage and sewerage treatment, quantity and 
characteristics of wastewater. Primary, secondary and tertiary treatment of wastewater, sludge 
disposal, effluent discharge standards. Domestic wastewater treatment, quantity of characteristics 
of domestic wastewater, primary and secondary treatment Unit operations and unit processes of 
domestic wastewater, sludge disposal. Air Pollution: Types of pollutants, their sources and impacts, air pollution meteorology, air 
pollution control, air quality standards and limits. 

Municipal Solid Wastes:= =>
 Characteristics, generation, collection and transportation of solid 
wastes, engineered systems for solid waste management (reuse/ recycle, energy recovery, 
treatment and disposal). 
Noise Pollution: Impacts of noise, permissible limits of noise pollution, measurement of noise 
and control of noise pollution. 


TRANSPORTATION ENGINEERING  = =>

Highway Planning: Geometric design of highways, testing and specifications of paving 
materials, design of flexible and rigid pavements. 
Traffic Engineering: Traffic characteristics, theory of traffic flow, intersection design, traffic 
signs and signal design, highway capacity. 

SURVEYING  = =>
Importance of surveying, principles and classifications, mapping concepts, coordinate system, 
map projections, measurements of distance and directions, leveling, theodolite traversing, plane 
table surveying, errors and adjustments, curves. 
 

WATERPROOFING MEMBRANES

A waterproofing membrane is a thin layer of water-tight material that is laid over a surface. This layer is continuous and does not allow water to pass through it. For example, on a flat terrace, a waterproofing membrane could be laid above the structural slab and below the finish tiles. This will ensure that water does not seep into the structural slab. The tiles and membrane must be laid over a filler material that is sloped to ensure that water flows into sumps and drains. Any water that remains as puddles over the tiles is likely to seep into the slab over time, so puddles are to be avoided at all costs.

These membranes are composed of thin layers of waterproof material. Most are about 2 to 4mm thick. There are essentially 2 types of membranes, sheet based membranes and liquid applied membranes.

Ideally, a waterproofing membrane should be strong, flexible, tear-resistant and elastic so that it can stretch to cover cracks and also move with the building. If the membrane is to be exposed to the sun, then it should be UV stable. The membrane should be flexible enough to take any shape it is laid over, and be capable of turning up and over walls and other construction features.

waterproofing membrane being installed
A bituminous membrane being installed.

SHEET BASED WATERPROOFING MEMBRANES

PictureA blowtorch is used to heat the bottom of the membrane.
As the name implies, these are membranes that arrive at the site in the form of rolls. These are then unfurled and laid on a firm surface. The most common type of sheet based membrane is a bituminous waterproofing membrane. This type of membrane is stuck to the substrate with a hot tar based adhesive using blowtorches. 

Joints between adjacent membranes are also made with the same hot adhesive. The sheets are overlapped by about 100mm (4") to form a waterproof joint. Some membranes are even joined by melting them with a hot air gun and then overlapping them on the previously laid sheet.

With this type of membrane, joints between sheets are critical, and must be done perfectly to avoid leakage.

Other types of sheet based membranes are PVC membranes and composite membranes. The latter have a fabric base that provides strength and tear resistance, and a chemical that coats the fabric to provide resistance.

Since these membranes are factory-produced excepting the joints, they are consistent in quality.

liquid applied waterproofing membrane
Spray-on membrane being applied. Image courtesy bridgepreservation.com

LIQUID APPLIED WATERPROOFING MEMBRANES

Liquid applied membranes come to the site in liquid form, which are then either sprayed or brush-applied on the surface. The liquid cures in the air to form a seamless, joint-free membrane. The thickness can be controlled by applying more of the liquid chemical per unit area.

Since the application procedure is very quick, a contractor will try and finish the entire area to be waterproofed in a single day to avoid cold joints. However, if a very large area is to be done on successive days, cold joints can easily be done by overlapping the new membrane over the old - the chemical will stick to itself readily.

These are generally considered to be superior to sheet based membranes as they are joint-free. However care must be taken in application to provide just the right thickness. The membrane can tear or break if it is too thin.

HOW TO SELECT A WATERPROOFING MEMBRANE = =>

Check for the following properties of the membrane:
  • UV Stability - if the membrane is to be exposed to the sun, than it must be UV stable or UV resistant, else it will degrade over time.
  • Elongation - this is the ability of the membrane to stretch. It is measured in percentages. An elongation of 150% means that the membrane can stretch to 1.5 times its length when pulled. Elongation is a must in buildings that will move, such as high-rise buildings, or buildings made with steel, which is flexible. This property will allow the membrane to stretch over cracks that may develop in the future. Membranes with elongation properties of over 200% are available.
  • Tear Resistance - this is an important property, as many membranes that have good elongation also can tear easily. Take a small sample of the material in your hand, and try and tear it into two pieces. This gives a fair idea of its tear resistance. You are looking for a membrane that will not tear even if a reasonable force is exerted on it.
  • Chemical stability - check that the membrane is chemically inert with respect to its environment in the building. Some membranes, especially outside basement walls, are exposed to the soil and rainwater outside.
  • Case Studies - ask the manufacturer or contractor to give you case studies where the membrane has been used. Ideally, it should have been in place for over eight years. Check with the building owners to see if any leakage or problems have occurred.

Sunday 17 August 2014

LOS ANGELES ABRASION TEST , HOW and WHY TO PERFORM

LOS ANGELES ABRASION TEST:



This is hardness test for aggregates, used in Laboratory  to determine the hardness value or abrasion value 
APPARATUS :

 Los Angeles Abrasion Testing Machine ,
Abrasive Charge – Cast iron or steel balls ,
Test sieve – 1.70 mm IS sieve ,
 Balance of capacity 10 kg , Oven , Tray

The aggregate used in surface course of the highway pavements are subjected to wearing due to movement of traffic. 

When vehicles move on the road, the soil particles present between the pneumatic tyres and road surface cause abrasion of road aggregates. 

The steel reamed wheels of animal driven vehicles also cause considerable abrasion of the road surface. 

Therefore, the road aggregates should be hard enough to resist abrasion. 

The principle of Los Angeles abrasion test is to produce abrasive action by use of standard steel balls which when mixed with aggregates and rotated in a drum for specific number of revolutions also causes impact on aggregates. 

The percentage wear of the aggregates due to rubbing with steel balls is determined and is known as Los Angeles Abrasion Value.



Key point of los angles test:

Rotate the machine at a speed of 30 – 33 revolutions per minute. The number of revolutions is 500 for grading A, B, C & D and 1000 for grading E, F & G. The machine should be

5 kg of sample for grading A, B, C & D and 10 kg for grading E, F & G

THE CALCULATION PART:

Original weight of aggregate sample = W1 g
Weight of aggregate sample retained = W2 g
Weight passing 1.7mm IS sieve = W1 - W2 g
Los Angeles Abrasion Value = (W1 - W2) / W1 X 100






Los angeles abrasion value should lies in below given range for different types of roads


Types of pavement layers                                         Max. Permissible Abrasion Value in %

1:WBM , SUB BASE COURSE                                                      60%

2:WBM BASE COURSE WITH BITUMEN SURFACE               50%

3: BITUMEN BOUND MACADAM                                             50%

4:WBM SURFACING COURSE                                                    40%

5: BITUMINOUS PENETRATION MACADAM                              40%

6:BITUMINOUS SURFACING DRESSING CEMENT
 CONCRETE SURFACING COURSE                                              35%

7:BITUMINOUS CONCRETE SURFACING COURSE                   30%

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