WHY CONCRETE NEED REINFORCEMENT ??

Reinforced concrete is mostly used for construction on a large scale due to its desirable mechanical properties. Reinforced concrete, or RCC, is concrete that contains embedded steel bars, plates, or fibers that strengthen the material.

Why concrete is reinforced??

Concrete can be very strong when it comes to absorbing stress in the form of compression. However, it does not perform well against tensile strength and crumbles when up against forces that tries to pull it apart. Concrete always experiences both kinds of stress in construction and if weight is put on the concrete beam from the top, it will hold up but deforms when it experiences tensile stress.

Reinforced materials are embedded in the concrete in such a way that the two materials resist the applied forces together.Concrete consists of a cement and stone aggregate mixture that forms a rigid structure with the addition of water. When steel that has a high tensile strength is embedded in concrete, the composite material withstands compression, bending, and tensile stresses. Such a material can be used for making any size and shape, for utilization in the construction.

The main quality of reinforced concrete is similarity of its coefficient of thermal expansion with that of steel, due to which the internal stresses initiated due to variation in thermal expansion or contraction are eliminated.

TOP FIVE RECENT DEVELOPMENT IN MECHANICAL ENGINEERING !!

1.)First turbine-powered street legal motorcycle -MTT Y2K SUPERBIKE

It’s the Most powerful production bike in the world which runs on diesel with kerosene. It has Rolls Royce-Allison gas turbine engine which produces 420 HP with 678 NM torque. 2-speed automatic transmission transfers excellent power, the top speed is more than 440 kph, weighs 230 kg. The design is great and fabricated from solid billets. It obtained Guinness World Record as the most expensive production motorcycle.

2.)Car engine - most powerful up to now 

The Devel Sixteen V16 Hyper-car - The custom made the real most powerful engine in the world is Devel Sixteen V16 Hyper-car which has 5000-hp, Quad-Turbo, 12.3-Liter V16. this is craziest power ever which has red-line of 8000 - hp. It is first revealed in Dubai Motor show, it reaches PS 0-60 in 1.8 seconds, and a top speed nearing 350 mph.

3.)Toyota launches first mass-market fuel cell car - Mirai, which converts hydrogen into electricity and emits nothing but water drops. It’s going to be the breakthrough in future for other vehicles like Forklifts, trucks, buses.

4.)Self driving Car

Google’s self driving car is almost driver less(manual assist needs in some dangerous turns) with start and stop option and which uses chauffeur system. The LIDAR(combined SONAR and RADAR) technology with Google map works in a precision manner. It uses 64 typical laser beams to find the objects around the car (360 degree). Cost of this system is around US $ 1 lakh. Accuracy, precision is more in this system which enables pre safe. Top speed is 40 kph.

5.)3D printing Technology

3D- printed steam turbine turbo-machinery used to convert Seawater into drinking water which was developed by GE.

Miniaturized Turbine used to compress and stream a mixture of air, salt and water through a hyper-cooling loop that freezes seawater. By freezing the mixture, the salt naturally separates in solid form, leaving just the ice. The ice is then melted, leaving clean water.

MULTIPLE CHOICE QUESTIONS ON ENGINE LUBRICATION SYSTEM !!

1-Lubricating oil

(A) Minimizes wear in moving parts

(B) Helps in keeping the parts cool

(C) Washes away and carries away dirt

(D) All of the above

(Ans: D)

2-Viscosity index (VI) is a measure for the change of viscosity with change in

(A) Temperature

(B) Pressure

(C) Volume

(D) All of the above

(Ans: A)

3-The following type of Lubrication system is used in two stroke engines

(A) Petroil (mist) system

(B) Wet sump system

(C) Dry sump system

(D) All of the above

(Ans: D)

4-In the following system, lubricating oil is carried in separate tanks from where it is fed to the engine

(A) Mist lubrication system

(B) Wet sump system

(C) Dry sump system

(D) Splash system

(Ans: C)

5-The following type of Lubrication system is used in Aircraft Engines

(A) Mist lubrication system

(B) Wet sump system

(C) Dry sump system

(D) Splash system

(Ans: C)

6-The following type(s) of Oil pump(s) is (are) used in Engine Lubrication system

(A) Gear type

(B) Rotor type

(C) Plunger type

(D) All of the above

(Ans: D)

7-The following is (are) oil pressure gauge(s)

(A) Pressure expansion type

(B) Electric type

(C) both (A) and (B)

(D) None of the above

(Ans: C)

8-The purpose of crankcase ventilation is to

(A) remove harmful particles from the engine

(B) provide proper lubrication to the engine

(C) provide air for combustion to the engine

(D) all of the above

(Ans: A)

9-The following part(s) is(are) lubricated by splash system

(A) Piston and piston rings

(B) Tappets

(C) Cams on camshaft

(D) All of the above

(Ans: D)

10-The following part is not lubricated by Pressure feed system

(A) Timing gears

(B) Valve rods and Push rods

(C) Rocker arms

(D)  Main bearings of crankshaft

(Ans: B)