Posts Tagged design of steel structures
Building Materials | Use of Carbon-negative Cement in Building Construction
Posted by BenzuJK in Building Construction on December 13, 2011
Carbon-negative cement | New revolutionary Building material
Carbon-negative cement…?? Sound different, doesn’t it?
Have you ever realized how much carbon is emitted because of using concrete in the construction of buildings, highways, dams, bridges etc?
Well, here’s an answer to that. It is found that out of the 100% carbon dioxide emissions, 5% of the emissions are caused by human activities. Majority of the carbon emission is caused by usage of concrete in the constructions. How? Cement is an indispensible ingredient used for making concrete. Cement is made by baking limestone and clay powders under intense temperatures (high temperature). The intense heat which is required for the production of cement is achieved by burning of fossil fuels which in turn release large amount of carbon dioxide into the atmosphere.
Building Construction | We can just imagine to what extent the carbon dioxide would be released into the atmosphere.
Carbon dioxide is also released when the conversion of limestone takes place in the kilns. This conversion is called “Calcination”. It has been observed that the amount of carbon dioxide emitted during calcination is much higher than that which is released due to burning of fossil fuels.
Recently, a British company called “Novacem” came up with this concept of manufacturing ‘carbon-negative’ cement that absorbs more carbon-dioxide than it emits over its entire life cycle.
Guide to Design of Simple Beam | Design of Steel Structures
Posted by BenzuJK in Building Construction on October 29, 2011
Design of Simple Beam
A member carrying loads perpendicular to its axis is defined as a beam.
For a simple floor beam, I-sections are used.
M/I = (sigma) /y
M = (I/y)(sigma)
I/y = Z (section modulus)
Therefore, M = z(sigma)
When beams are loaded, bending stresses are developed at all sections.
The bending stresses developed in beams can be determined by the equation theory of simple bending.
For laterally supported beams, the permissible bending stress in tension as well as in compression should not exceed (sigma)bc or (sigma)bt = 0.66fy
For laterally unsupported beams, the permissible stress in bending compression is calculated by using tables from the the IS code book (IS:800).
Load carrying capacity of the Beam
From structural steel tables for the given beam, the section modulus (Zxx) is obtained.
Depending upon whether the beam is laterally restrained or unrestrained; the value of permissible stress in bending compression ((sigma)bc) is calculated.
The moment of resistance of the beam is found out.
MR = Zxx .(sigma)bc
Equating the moment of resistance to the maximum bending moment equation, the total load (w) the beam can carry is calculated.
Guide to Design of Built-up Beams
Posted by BenzuJK in Civil Projects on October 28, 2011
Design Procedure of the Built-up Beams design
In my earlier articles, we discussed in detail about the “Theory of Built-up Beams“. In this article, we will move a step ahead and understand the concept of the design of Built-up beams.
Here are the simple steps that are to be followed for the design of Built-up Beams.
Step one
The effective span and load required to be carried by the built-up beam are known.
Maximum bending moment and shear force in built-up beams are calculated.
Step two
Value of yield stress (fy) for structural steel is to be assumed.
The permissible bending stress (sigma bc) is calculated.
Step three
The required section modulus (Z) for the given beam section is calculated.
Guide to designing a Rolled Steel Beam
Posted by BenzuJK in Building Construction on October 20, 2010
Six Step Guide to Designing a Rolled Steel Beam
Here are a few simple steps that are to be followed for the design of Rolled Steel Beam:
Step one
Calculate the maximum Bending Moment and Shear Force
Step two
Depending upon whether the beam is laterally restrained or unrestrained, calculate the permissible stress in bending compression (sigma bc) using the equation;
sigma bc = 0.66fy
Step three
Find the required Section Modulus (Zreq)
Zreq = M/sigma bc
Step four
From the structural tables, choose a suitable section such that the section modulus is slightly more than the required section modulus.
Step five
Check for shear.
Calculate the maximum Shear force in the beam. Calculate the average shear stress in the web and this should be less than 0.4fy.
Tv = (Shear Force)/HLw
where = H = height of the web
Lw = length of the web
Step six
Check for deflection
Ymax < 1/325 of span
Structures and Classification of Structures | Design of Steel Structures
Posted by BenzuJK in Building Construction on September 7, 2010
What are Structures?
When any body is subjected to a system of loads and deformation takes place and the resistance is set up against the deformation, then, the body is known as structure. The structure are means of transferring forces and moments. The structures may be classified as statistically determinate structures and statistically indeterminate structures. When the equations of statistics are enough to determine all the forces acting on the structures, in the structures, then, the structures are known as statistically determinate structures.
Design of Steel Structures
When the equations of statistical equilibrium are not sufficient to determine all forces acting on the structure and in the structures, then the structures are known as Statistically Indeterminate Structures. The equations of consistent deformations are added to the equations of equilibrium inorder to analyse the Statistically Indeterminate Structures.
Classification of Structures
The structures are categorised by their supporting systems. There are one dimensional, two dimensional and three dimensional supporting systems.
- When a supporting system is subjected to only one type of stresses, then, it is known as basic system.
- When a system is subjected to simultaneously several types of stresses, then it is known as mixed system.