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Showing posts from October, 2020

Civil Engineering Softwares

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                           As a civil engineer, we need to have knowledge of different software according to the field we choose. We have different software in different fields of engineering such as in hydropower we have some software whereas in fields like road we have others. What we must understand is that having knowledge of all the software is not necessary for a civil engineer but we must have knowledge of the software which are related to our field of interest. Nowadays the concept of Building Information Modelling (BIM) is being practiced and is in an early stage.  Building information modeling  ( BIM ) is a process supported by various tools, technologies, and contracts involving the generation and management of digital representations of physical and functional characteristics of places. BIM is actually a concept that is being practiced widely abroad. During design as well of construction BIM software are used which gives wide varieties of function and multi taskings. BIM s

Bar Bending Schedule (BBS)

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            Bar Bending Schedule is a very important knowledge an engineer should have and it is even more important for the site engineers. Basically, Bar bending schedule is used to obtain the quantity of rebar in a construction.  BBS includes the cutting length of rebar, size of rebar, bending of rebar and total quantity of rebar.          BBS is a very important document which needs to be included in the Running Bill (Interim Payment certificate) prepared by the contractor. Hence BBS is generally prepared by the contractors engineer and approved by the consultants. However in big projects such as hydropower the BBS is prepared by the District Resident Engineer from consultant. It is better to prepare BBS during the site is running and when needed.  BBS provides the total quantity of rebar used and it is updated in every IPC. BBS also helps the barbenders to prepare the rebar which needs to be installed. It is very user friendly and can be understood easily.                 Basicall

Thumb Rules on Rebars in Civil Engineering

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                                                As a civil engineer it is better to have knowledge about the thumb rules. These rules are quite useful in sites. However, the values obtained from these thumb rules might not be correct so calculation must be done for proper estimation.  Thumb rule only helps to get an idea about the result. Below are some of the practised thumb rules in civil engineering: - 1)      Thumb rule for Steel quantity required for Slab, Beams, Footings & Columns: -                Steel required in Residential buildings = 4.5 Kgs to 4.75 Kgs / Sq. Ft.                Steel required For Commercial buildings = 5.0 Kgs to 5.50 Kgs/Sq. Ft. 2)      Percentage of Steel in Structural Members:               a ) Slab – 1% of the total volume of concrete               b ) Beam – 2% of the total volume of concrete               c ) Column – 2.5% of total volume of concrete               d ) Footings – 0.8% of the total volume of concrete Example: How to calc

Development Lengths

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  Development length? It is a term we hear in RCC subject in engineering while we talk about rebar.  So what actually is development length? It is very important for a fresh site engineer to know about the development length. The definition of development length is “ A  development length  can be  defined  as the amount of reinforcement(bar)  length  needed to be embedded or projected into the column to establish the desired bond strength between the concrete and steel  .” This definition can easily be found in google. What we need to learn is how to calculate the development length. Development length is denoted by Ld. Development length depends upon following:- 1)       Diameter of rebar 2)       Grade of steel 3)       Grade of concrete As per IS 456:2000 clause 26.2.1 Development length= (Día of bar *grade of steel) /(  4* Design bond  stress  (ζbd)  )                                                    *Value of Design bond stress is given on code which differs fr

Specification of construction material in building

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 Construction material code: -            Construction material is the materials used in the construction process of any kind of structure. The selection of construction material is very much important in construction in order to ensure the quality of the work. Some of the materials in building construction are shown below: - 1) Cement: -            Cements stored more than two months from the date of receipt should either be avoided or tested in the lab. Cement should be ordinary Portland cement meeting the requirement of NS049-2041. 2) Coarse Aggregate: -            Shall consist of crushed or broken stones, shall be hard, strong, dense, and durable. Should be angular in shape, flankey elongated pieces shall be avoided. Aggregate should confirm the requirement if IS 383-1970 and IS515-1959. Sizes: -           a) Normal cement concrete with a thickness of 100mm and above graded from 20mm downward.           b) Cement concrete from 40mm to 100mm thickness is graded from 12mm downward.

Notes on building

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      1)       Horizontal formwork is called centering and vertical is called shuttering.       2)       In slabs bars parallel to the shorter span are main bars. They are laid below distribution bars.       3)       In slabs bars parallel to longer span are called distribution bars. They are laid above main bars.       4)       In the slabs bar is cranked at one side then the bar is straight at the other side in slabs.       5)       At the corner of each slab what happens is that the crank and the straight bars from both the sides merge at the point and make a mesh like formation of rebars.        6)       The thumb rule is rebar size in slab should not be greater than 1/8 th of the depth of slab and the minimum diameter for slab rebar is 8mm.       7)       In discontinuous end bars are bent U-turn after providing upto end of slab and extended upto (L/4) length from the face of the beam where L is the span of the slab on the direction of the rebar . For continuous end

Water Supply Part-1

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                                Let's talk about a topic in which currently I am working on which is pipeline work. I am working currently as a contractor in a water supply project. Basically, in a water supply system, there are two parts which are: - Structure Part Pipeline Part Structure Part: -                           The starting of the structural part consists of an intake structure. Then from there, raw water is taken to another structure called a grit chamber and sedimentation tank. From the sedimentation tank, the raw water is taken to another structure called the water treatment plant where the raw water is purified. Then the purified clear water is taken to different storage structures such as reservoirs and overhead tanks. This is a very brief introduction to the structure portion of a water supply system. Here we are going to discuss the pipeline part. Pipeline Part: -                         We all know what is a pipeline. It is laying of pipe for the flowing of flui

Torsion in building

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  What is torsion? Today we will talk about the effects of torsion in the civil engineering field. Torsional force affects not only the civil engineering structures but also other mechanical structures too. What causes the torsion? Basically, torsion is caused by the force called torque on the free end of the structure when the other end is fixed. In buildings, torsion is created when the center of mass and center of stiffness (rigidity) doesn’t coincide. The distance between these two points is referred as torsion eccentricity. The lateral load acts on the centre of mass and the opposing force acts through centre of stiffness. Due to this a couple is developed which tries to twist the building. Hence whenever we design a building either manually or using software we must check the torsional eccentricity. Center of mass is generally the geometric center of the floor or building. Location of the center of stiffness depends upon characteristics of the components of the lateral