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Civil Engineering
Civil Engineering is a profession of designing and executing structural works that serve the general public, like houses, buildings, roads, etc. A Civil Engineer is an engineer trained in the design and construction of public works, such as bridges or dams, and other large facilities.
4,921 Questions
How does torsion effect a bridge?
There are 3 ways to prevent rusting
A. Plate the metal with another metal, expensive.
B. Paint or coat the metal with a chemical that prevents the metal from getting wet.
C. Chemically treat the metal so it can only rust a little and it cannot rust through.
Depending on what you are working with would determines the method you use.
What is the BS concrete design mix for class 20?
40 20 concrete design mix is the water to cementitious materials ratio. This is what determines the class of the design mix.
When was the humber bridge built?
The Humber Bridge, spanning The Humber Estuary between Yorkshire and Lincolnshire had been planned since the 1930's.
Construction began on 26 July 1972 and the bridge was opened to traffic on 24 June 1981.
There was an official opening ceremony, conducted by Her Majesty Queen Elizabeth II, on 17 July 1981.
Work began in 1973 and the bridge finally opened in 1981, so it took 8 years to build.
How is a roller-bug used to lay concrete?
for sure it affects the surface to a certain limit as you increase the paste on the surface and decrease the aggregat amount which may lead to surface abbraision...using surface hardner will help to strenghten the surface.
Can you calculate pipe diameter if you have pressure head and discharge flow?
Static pressure is .434 X height Example 10 ft x .434 4.34 PSI to prove take 2.31 PSI x 4.34 To find FORCE to need to calculate the diameter of the piping and the height and then the weight of the water inside the pipe
The mass of polystyrene is easily estimated looking at its mass spectrum. The spectrum has the shape of a comb with a large number of teeth. Teeth are equally spaced. In the region between 1000 and 3000, the spacing is 104.12 g/mol. In the region between 3000 and 6000, the spacing is 104.18 g/mol. If the and the spacing is approximately 104.12 g/mol. The spacing changes
Which is weaker shear strength or tensile strength or compressive strength?
That all depends on the material
For most all metals, tensile strength is stronger by about factor of 1.7
For most metals tensile strength is equal to compression strength
For concrete, both comppression strength and shear strength are higher than tensile strength
For many composites, tensile strenght is higherthan compression strength
What is the minimum cover required for steel in concrete?
The cover required is a function of the serviceability required for the building, meaning if you need longer fire protection then the cove becomes more... at the moment i don't know the calculations(still studying) but the minimum cover is 25mm(acording to the South African code) or 1inch Also at coastal regions the cover should be more to prevent rust of the steel
If your mix will require some amount of "man-handling" to properly place, a slightly wetter mix will make that easier. A drier mix is nice when forming curbs and inclined surfaces, or if you need to get the surface finished and nicely troweled in a hurry.
A standard size wheelbarrow will hold a manageable size mix using 2:4:6 (simply doubling the formula.) This is enough concrete to fill a large post hole
For a very small batch, use a 3/8" minus gravel. For a larger batch you could use 3/4" or even 1" minus if you need to stretch your sand and cement.
Answer16 shovels of sand,7shovels aggragate(small rock),and on 90lb.bag Portland cement,4 to 7 gal. clean water.
AnswerPlace above dry mix in suitable mixing conatainer (such as a wheelbarrow), add water slowly while turning the dry mix with a shovel or hoe. Continue adding water until mix has desired consistancy. Slightly 'dryer' than pancake batter is my preference.
Answera small child's swimming pool is what i have used for a long time their cheap and disposable ( I take mine to the recycling drop off after they crack)
AnswerThe old Italian way is to place the cement and sand mixture in a pile on a flat surface. Using a shovel make a hole in the center, creating a ring. Pour water in the center and start bringing the dry material into the center. Keep doing this until the material has become completely wet. Continue to turn the mixture over with the shovel combining everything into a firm but moist consistency. To test if your mixture has enough cement in it, pull some out with your index finger and turn it upside down. If it sticks then you're good; if it falls off you have too much sand. Please note that cement WILL burn through your skin, so make sure you wash your hands.
you can also use a 5 gallon pail. add about 2 quarts of water to the pail , add approx. 40 # of concrete mix, than add about 2 quarts more water, than mix with a landscape shovel by by twisting in the bucket, till you have a pancake thickness.
AnswerA classic concrete recipe is one shovelful of Portland cement to two shovelsful of sand to three of small rock. You want ROCK, not gravel--gravel is graded for size, and using rock of varying sizes gives the concrete more strength since the little rocks interlock with the bigger ones. Anyway, you want a wheelbarrow to mix it in, a mortar hoe (it's got two holes in the blade) to mix it with and forms to put it in.
Can you used other type of capacitor instead of electrolytic?
depends, there are nonelectrolytic capacitors but it might not work for your circuit. research what kind you need and then use the right ine :D xx
What are the risks of telecommunication masts?
In general microwave frequencies are electromagnetic waves with frequencies in the range of 300 MHz to 300 GHz. In this range is the 2.4GHz is used in microwave ovens to heat food where water, sugar and fats absorb this radiation. This method is called dielectric heating. This is what is harmful to humans and what cooks the food in a microwave oven.
I have heard many rumors of concerned parents claiming cell phone towers at schools are harmful to their children.
A cellular beacon or tower, known as a cell-site, actually controls and limits it's RF output power for the sake of interference in reusable RF channels. This means they specially limit the output power so that the output does not range to far and interfere with other "cells". The best way to bring insight to this phenomena which is very hard to quantify for non-technical individuals who seems to makeup the largest part of the concerned community, is to use relative measures which can be better understood.
In this article we will use mW per square meter as a measure of microwave (harmful) radiation.
The ground-level power densities near typical cellular towers are on the order of 10 mW per sq meter or less while the sun radiates about 250 000 mW per sq meter average per 24 hour day which means, that during the day it's even much more. The radiation from the sun on the earth is about 25 000 times more than the radiation under a cell-site(cell phone tower) per sq meter.
The microwave oven in the kitchen have a magnetron (source of microwave radiation) that can produce in the order of 800W or 800 000mW microwave power, the shielding in the microwave oven will ensure a leakage at 5cm distance of radiation less than 10 000mW per sq meter.
So lets compare electromagnetic radiation magnitudes.
1) Sun average radiation on the earth = 250 000mW per sq meter (full electromagnetic spectrum)
2) Microwave oven leakage (5cm distance) = 10 000mW per sq meter (microwave)
3) Directly under cell site = 10mW per sq meter (microwave)
The safe standard for Specific absorption rate (SAR)is about 2000 mW/kg body tissue for cell phones. Although generally for other devices up to 10 000mW/kg can still be seen as safe.
The amount of radiation may vary according to position and distance, cell-sites are not isotropic radiators, this means that they are directional. The power they produce in front of them in the direction they are focused is much more than the power behind or below them. The antennas are often mounted three on tower to form hexagon cell and to produce a near omni-directional coverage. They appear to be harmless.
A single kilogram equals around 2.2 grams. That means when calculating 50 kilograms, the equivalent in pounds is around 110.
Whats the difference between a bridge and a viaduct?
A viaduct is a type of bridge, but it has several spans, usually of equal length. Bridges and viaducts can span land or water.
In Romance languages they differentiate between viaduct (bridge over land) and 'ponte' (bridge over water).
In highway engineering what is the difference between a grade separator and a flyover bridge?
There is no point of difference between grade separator or a flyover bridge.The point is that a grade separator can either be a flyover or an under pass, that is any structure which separates the uniform grade of a running highway into two different grades.
Also considering the cost fact grade saperator is more cost effective as far as my knowledge.Who gets paid more a civil engineer or a mechanical engineer?
Depends on where you are. In California entry engineers make $50-60k, decent engineers with 10 yrs exp make 70k, and PHDs/experts usually don't make more than $120k. If you're in industrial salaries are $20k higher for same yrs experience usually. But if you are working on oil&gas projects in offshore areas such as northern Canada you can top $200k. If you are project manager you make $180-250k and engineer lead managing 40-100 ppl = $400k, over 200 ppl makes over $500k in Canada.
How do you calculate shear strength?
Yield strength is not a characteristic that can be calculated. It must be derived through experiment. You need to measure yield strength experimentally. Through experiment you'll measure about a hundred specimens, and then calculate the average and the standard deviation. For performing design work, subtract 2 times the standard deviation from the mean and use the resulting value for your design calculations. Yield strength is usually found in design tables and charts for a given material. Thus, if you have a given material with which you are working and wish to discover the yield strength, you're best bet is to see what the supplier or (better yet) the manufacturer has to say about it. Unless, that is, you have a well-equipped laboratory handy so you can conduct your own experiments.
How do you determine shear center for any section?
the sum of all vertical forces is called shear force
Who made the first paper air plane?
Historians believe that the first paper airplanes were made by the Ancient Chinese, though exactly when and where is not known. The Ancient Chinese were producing paper on a large scale in 500 BCE, and between the years 460-390 BCE, the art of paper folding and origami were common and popular activities in China.
What is formula to calculate steel rod weight per inch?
Steel rod weight per inch.... this depends on the thickness and shape of the steel rod.
The density of steel is around 500 pounds per cubit foot, so, for example:
If the rod is cylindrical and has a diameter of 1/2 inch, each "inch" of the rod is a cylinder with length L=1. The volume of this cylinder is found with pi*r^2*L.
Since diameter = .5in, radius = .25in.
pi*.25^2*1 = about .2in^3 or 1/5 cubic inch.
Now, a cubic inch is about 5.8*10^-4 cubic feet, so...
500lb/ft^3 * 5.8*10^-4 in^3/ft^3 = .28935 pounds per cubic inch.
We have one fifth cubic inch, so multiply that by .2...
and each inch of our rod weighs .05787 pounds, which is pretty much 3/50 pounds.
Coincidentally, 3/50 of a pound is just about an ounce, so our cylindrical steel rod of diameter 1/2 inch pretty much weighs one ounce per inch!
What is the meaning of civil in civil engineering?
Historically, the term civil engineering was introduced to differentiate the peace time non military form of engineering intended to improve the natural and built environment for the benefit of mankind from military engineering (which is intended to support offensive, defensive or logistical operations in time of war).
How do you calculate load on steel beams?
try this website it might help - http://www.engineeringtoolbox.com/beams-support-forces-d_1311.html first off the calculations are based on beam size (example w14x26 [14=14" x26=lbs. ) which is around 5 3/16" wide x 13 7/8" high the flange thickness is around 3/8" thick and the web would be 1/4" wide you also must check the span and application (concrete Pier's, or schedule 40 columns (1/4" thick steel column) there are other factors which are involved in other words consult your engineer
What is the density of mild steel bar?
The density of mild steel typically ranges from about 7,750 to 8,050 kg/m³ (or 7.75 to 8.05 g/cm³). This variation can depend on the specific composition and processing of the steel. Mild steel, primarily composed of iron with a small percentage of carbon, is known for its durability and versatility in construction and manufacturing applications.
