Civil Engineering

Main difference between local and overall buckling related to distortion of the overall system geometry. Local buckling does not cause distortion of the overall geometry, usually local buckling seems on short (channel or angle) compression members (excessive loaded and material related problem). On the other hand overall buckling causes distortion, we can give example as plastic ruler compressed by fingers . There is equation on buckling developed by Euler.

mores

concrete (cement) cures with age, well at least up to a point.

think of breaking up the concrete slab that was cast yesterday evening, versus a concrete slab that is a year old.

the optimum strenght of concrete (maximum strenght it is assumed to reach) is statistically reached after 28 days, if proper and adequate curing took place, and normal working / exposure conditions and control of quality took place. Curing is basically protection against severe exposures as draft winds that may cause cracking, and keeping the surface moist over the 7 days, by covering it with DPC plastic or regular sprinkling with water.

after only 7 days of curing, the 28 day strenght can be accurately predicted to determine if it will pass the requirements.

after 7 days (I have also seen 24hrs samples) a cube sample is crushed to determine the 7 day crushing strength. this sample was then cast at the same time as the structure being assessed.

the 7 day strenght is measured in Mega Pascals (Mpa) or equivalent units Kilo Newton per square millimeter (kN/mm2) and really depends on the application the concrete is used for:

walkways will probably be 10Mpa

single storey building footings and floor slabs, say 15Mpa

floor slabs where vehicles may drive could be even 35Mpa.

Suspended slabs, like first floor slabs etc, say 40Mpa.

precast concrete

manufactring the members of construction out site - using concret material-

3 KG / Meter

The ratios of cement to sand to aggregate for the different grades of concrete are as follows. M10 has a ratio of 1:3:6. M15 has a ratio of 1:2:4. M20 has a ratio of 1:1.5:3. M25 has a ratio of 1:1:2, but M30 has no set ratio. It is a designed mixture to achieve the stress tolerance desired.

It all depends on the type and sizes of the steel used. It also depends on the load that the concrete has to take at certain points. 7865kg is the weight of a cubic meter of steel.

Typical examples;

A pile cap could contain 400kg/m3

A heavy duty industrial slab or structure could contain 200kg-400kg/m3

A footpath could contain 40kg/m3

(all depends on the design, but numbers above should give you a rough answer)

The Atterberg limits of a soil are used as an integral part of several engineering classification systems to characterize fine-grained soils. Also these limits are used directly in specifications for controlling soil for use in fills, and in semi-empirical methods of design. A wide variety of engineering properties of soils have also been correlated to the liquid limit, plastic limit, and plasticity index of soils (i.e. Compressibility, Permeability, and Strength).

Stiffness is defined as the ratio of load per unit deformation.

Silt is used to build bricks, grow crops, make sedimentary rocks and concrete.Silt is also very thin and can be mistaken by sand.

Apexvs.

The sewage system in a neighborhood

Deformed steel bar is more commonly known as reinforcing bar, or rebar. These steel bars are imbedded in concrete to provide tensile strength. Smooth bars are run through rollers which "deform" the bar thereby adding ribs. The ribs provide a mechanical bond between the steel bars and the surrounding concrete.

what do you mean by frost line frost will penetrate up to three feet in the dead of winter if that is what you are asking.

The only certain application of Bernoulli's Theorem I know is in the Bernoulli's Theorem experiment in college. All other examples are in my opinion a restatement of Newtons Laws, a missinterpretation of results or a failure to fully understand what is physically happening such as in the fallacy that lift in an aerofoil is due to BT. Bernoulli's Theorem is used by the Fire Brigade to calculate velocity and range of different types of fire-fighting equipment. Going hand-in-hand with the Venturi effect, it help to calculate reach and pressure required to obtain that reach during fire-fighting operations. Example: A pump supplies 6kW of energy to the water flowing thorugh a 45mm hose. If the water flows 25m vertically and through a 25mm branch at a rate of 480l/min, use Bernoulli's equation to find pressure at the branch.

GTS benchmark is called Great trigometical survey benchmark.

its position is decided by survey of India department.

it RL is decided with reference to MEAN SEA LEVEL.

no of benchmark, position and location is given in catalogue of survey of India department.

There is an old joke: "What's the difference between civil and mechanical engineers? Mechanical engineers build weapons -- civil engineers build targets." Yuck yuck. In reality civil engineering involves the design and construction of buildings, roadways, bridges, railroads, water supply, drainage, and sewers. Sometimes this is referred to as "infrastructure" Usually these are larger things that have a long service life. Mechanical engineering deals with machinery -- automobiles, trucks, machine tools, engines, pumps, and things of that nature -- including weapons. Typically it involves shorter service life, smaller size (although there are some Really Big machines out there!) and more precision.

A. You can study when it's convenient for you. B. You can interact with other students. C. You don't have any homework. D. You don't have to take any examinations.

as a civil engineer we should construct dams and pipelines across countries for transportation of oil,petrol,gases,etc.in these cases we should know the behaviour of fluids so that structures could be designed in such possible manner for ease of flow of fluids.fluid mechanics serves this purpose.

section modulus of any section is the ratio of the moment of inertia to the distance of extreem fibre from the neutral axis. plastic section modulus is the section modulus when the cross section is subjected to loading such that the whole section is under yield load. numerically it is equal to the pdoduct of the half the cross section area and the distance of center of gravity of tension and compression area from neutral axis

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The serviceability limit state is the point where a structure can no longer be used for it's intended purpose but would still be structurally sound. The tolerances for serviceability depend on the intended use of the structure and can vary significantly.

For example machine foundations often have extremely small tolerances for differential settlement which if it occurred would render the machines unusable (without causing any damage), whereas the same level of differential settlement on a road or embankment would have virtually no effect on its use.

The ultimate limit state is reached when the applied stresses actually exceed the strength of the structure or structural elements causing it to fail or collapse.

3 years