Civil Engineering Notebook (CEN)

NEXT QUIZ Today at 2 PM TOPIC👇 INDEX PROPERTIES UNIT,CLASSIFICATION OF SOIL be ready👍👍

Tomorrow Quiz At 11 AM be ready Topic👇 ✅ INTRODUCTION ✅BASIC DEFINITION & RELATIONSHIP 📝😊👍

🔰CEN FACT 📝Bitumen is a non-crystalline solid or viscous material derived from petroleum, by natural or refinery process.The main constituent is petrolene a yellowish oily substance, an excess of which makes bitumen to melt at low temperature and, asphaltene hard black substance, an excess of which makes bitumen brittle and non-plastic. 📝Bitumen is not affected by light, air or water individually, but in combination they can make it brittle, porous and susceptible to oxidation forming blisters and cracks. 📌Characteristics of Bitumen: 👉It is asphalt in solid state and mineral tar in semi fluid state. 👉Bitumen is brown or black in color. 👉Their composition is carbon 87 per cent, hydrogen 11 per cent and oxygen 2 per cent. 👉It becomes soft at temperatures between 30°–100° C and therefore, must be protected from exposure to heat. 👉It is insoluble in water and fairly resistant to most acids. 👉It is soluble in carbon disulphide.  #building

❄️CEN FACT❄️ ✅Transverse Stiffeners are provided to increase buckling resistance of the web due to shear, It is provided vertically along the span. ✅Horizontal Stiffener / Longitudinal Stiffener is designed to prevent web buckling due to bending compression. ✅End Bearing Stiffeners are provided at the supports & Load Bearing Stiffeners are provided at the points of concentrated loads. #steel

❄️CEN FACT❄️ The initial setting of Portland cement is mainly due to tricalcium aluminate. 📌Tricalcium aluminate (C3A): 👉This is also called Celite. 👉It is the quickest one to react when water is added to the cement. It is responsible for the flash setting.  📌​​Tricalcium silicate (C3S): 👉This is also called Alite. 👉Tricalcium silicate hydrates quickly and contributes more to the early strength 📌​Tricalcium silicate (C2S): 👉This is also called as Belite.  👉The contribution of dicalcium silicate takes place after 7 days and may continue for up to 1 year. 📌​Tetra calcium Alumino ferrite (C4AF): 👉This is called as Felite. 👉Tetracalcium alumino-ferrite is comparatively inactive.​ #building

❄️CEN FACT❄️ Cavity wall 👉Cavity wall is constructed with two separate walls for a single wall purpose with some space or cavity between them. These two separate walls are called leaves of cavity walls. The inner wall is called an internal leaf and the outer wall is called an external leaf. 👉Cavity wall is also called a Hollow wall. Advantages of Cavity Walls 👉Cavity walls give better thermal insulation than solid walls. It is because the space provided between two leaves of cavity walls is full of air and reduces heat transmission into the building from outside. 👉Economically they are cheaper than solid walls. 👉Moisture content in the outer atmosphere is not allowed to enter because of the hollow space between leaves. So, they also prevent dampness. 👉They also act as good sound insulators. 👉They also reduce the weight on the foundation because of their lesser thickness. 👉Outer Efflorescence is also prevented. #building

The following are some of the general guidelines to be considered while planning a staircase: 1. The respective dimensions of tread and riser for all the parallel steps should be the same on the consecutive floor of a building. 2. The minimum width of stairs should be 850 mm, though it is desirable to have a width between 1.1 to 1.6 m. In a public building, cinema halls, etc., large widths of the stair should be provided. 3. Generally, the number of risers in a flight should be restricted to twelve. 4. The minimum vertical headroom above any step should be 2 m. 5. The size of the tread generally ranges from 270 mm for residential buildings and 300 mm for public buildings. 6. The size of the riser generally ranges from 150 mm for public buildings to 190 mm for residential buildings. 7.The minimum width of landing shall be equal to the staircase width. #bcm

#bcm

Solution: 1 Explanation: Staircase: Stairs are a set of steps that give access from floor to floor. The room or enclosure of the building, in which stair is located is known as the staircase. A staircase provides access & communication between floors in multi-story buildings. #bcm

Q41)The maximum number of steps in a flight should NOT be more than 1 12 2 15 3 10 4 8

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OBC 13 परसेंट HOLD I MP SUB ENGINEER JOINING LETTER INFO II क्या क्या निर्देश मिले हैं विभागों को II https://youtu.be/p55Ob2MqSyY

Day after tomorrow we will solved UPPSC Polytechnic Lecturer civil paper1 with detailed explanation on CEN+, Hurry up & join https://rigipay.com/g/0Uloe5mSEi

Calculations: Given,   LL =  40%  and   PI  =  28%     Equation of A-line- 👉Plasticity index PI = 0.73 ( LL-20) = 0.73(40 - 20)  = 14.6 👉IP of soil  > IP of  A-line 👉It will lie above A-line and also 35 < WL < 50 So it is CI. Additional Information Equation of U- line IP  =  0.9 (WL - 8)  #soil

CL- clay of low plasticity CI - clay of medium plasticity CH - clay of high plasticity ML - silt of low compressibility MI - clay of medium compressibility MH - clay of high compressibility #soil

Solution: 2 Concept : It is adopted by IS code. It was given by A-line Casagrande. It uses particle size distribution for coarse and plasticity for fine soils. Equation of A-line Ip = 0.73(Wl - 20 ) Soil classification as per Indian standards: #soil

Q24)As per Indian standard soil classification system, a sample of silty clay with liquid limit of 40% and plasticity Index of 28% is classified as 1 CH 2 Cl 3 CL 4 CL-ML