Seismic Zones in India

In the field of seismology, seismic zones are, areas divided based on the frequency and intensity of expected earthquake. Indian subcontinent comprises of four seismic zones those are- II, III, IV and V. These zones are categorized based on scientific research related to seismicity and earthquake occurrence in the past years.

Earlier India was divided into five zones, but then, The Bureau of Indian Standards [IS 1893 (Part I):2002] decided to group the country into four seismic zones, where, the first and second zone being unified.

The Bureau of Indian Standards is responsible for publishing seismic activities in terms of seismic hazard maps and codes. They brought out a total of three versions of seismic zones; a six zone map in 1962, a seven zone map in 1966 and a five zone map in 1970/1984.

Seismic Active Zone:

Seismic Zone II: This is the area that suffers least damage of the other three zones. Intensity of earthquake lies between intensities V to VI of MM scale (MM – Modified Mercalli Intensity scale).

Zone II covers those areas which are not covered by the other zones listed below.

Seismic Zone III: Zone III receives moderate damage. This damage corresponds to intensity VII of MM scale.

States that lie under this zone are- Tamil Nadu, Orissa, Andhra Pradesh, Maharashtra, Chhattisgarh, Bihar, Jharkhand, Bihar, Madhya Pradesh, Kerala, Gujarat, Goa, Lakshadweep islands, West Bengal, Karnataka, parts of Punjab and some remaining parts of Uttar Pradesh.

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Rajib Dey
www.constructioncost.co
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Porotherm Bricks : Properties, Advantages and Applications

Porotherm clay bricks are special type of bricks made using natural clay, coal ash, rice husk, and granite slurry. Apart from the common size 400x200x200mm, they come in various sizes. They help in providing walling system which aids in thermal insulation resulting in cooler interiors in hot summer and warm interior in cold seasons. These clays apart from being environmentally friendly, they are economical and easy to use.

Properties:

a. The compressive strength is greater than 3.5MPa.
b. High thermal and sound insulation.
c. Low weight.
d. High fire resistance.
e. Density range from 694 to 783 kg/m3.
f. Large size but light in weight.
g. Water absorption is around 15.

Advantages:

1. Environmental Friendly: Porotherm bricks are made up of recycled materials hence, they’re eco friendly.
2. Cost Effective: Porotherm bricks save lot of energy by cutting operation and construction cost.
3. Speed of Construction: Due to its lightweight nature and ease of handling, it increases the speed of construction.
4. High Durability: They’re highly durable and can easily resist fire and carbonation, thus possess long life.
5. Thermal Insulation: Perforation of these bricks results in great thermal insulation.
6. Good Strength: Porotherm bricks are manufactured at high temperatures. It’s composition includes teeracotta which adds strength to the brick. Compressive strength of porotherm brick is greater than 3.5MPa.

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Case Study: Vista Tower, Chicago

The construction business in Chicago has always been successful, to say the least. The city hosts major buildings and modern landmarks, as well as widespread infrastructure expansions and land developments in the outskirts of the prestigious city. By analyzing and understanding some of the biggest projects in the city, completed or ongoing, we can realize the technology and the efforts that went into developing them. This is called case studies, which are one of the best ways to understand the construction industry overall.

Today we will look into the construction of the Vista Tower in Chicago. Located at 363 East Wacker Drive, Chicago, Illinois, the construction of this megaproject is still going on and is scheduled to finish by 2020. This is going to be the third tallest building in Chicago after the Willis and Trump Towers.

The official name of the complex is Lakeshore East, and it will host a mixed-use building with both residential and hotel usage. The Vista Tower is supposed to be 101 stories tall at 1198 feet (365 meters), and it will be divided into three buildings respectively of 47, 71, and 93 stories. The building was designed to contain 406 condos and 210 hotel rooms under the Wanda Vista five-star hotel.

Designed by Jeanne Gang, the Vista Tower is being constructed by the Magellan Development Group and the Wanda Group, who are going to pump in nearly a billion dollars into the project. Point to note here that when completed, the Vista Tower will become the world's tallest structure designed by a female architect.

The Tower's proximity to the Chicago River and Lake Michigan's lakefront park system will allow the building to define the skyline with a high level of prominence. The brilliantly imagined vertically stacked frustums (pyramids with the tops cut off) made of reinforced concrete will be adorned with a flowing glass facade, colored in gradients. The building will have 19 such frustums (at most) with spandrel covered floor slab edges, which is expected to create a unique visual texture for the outer skin.

The tower being so tall, may fall victim to wind-induced swaying. To prevent this, seven water-filled tanks are placed atop the tower. When the building is pressed by the wind to sway is a certain direction, the water in the tanks will slosh in the opposite direction which in turn will offset the swaying effect. Also, since this is not enough to prevent high powerful winds exerting more power on the building sides, there will be a large "blow-through floor", the first of its kind in Chicago, near the top of the tower which will let these winds through.

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Top Ten Construction Projects in World

The Construction industry is something that never stops. To achieve more living space, better infrastructure, production facility, and development, we need to be building some stuff all the time, expanding our concrete footprint everywhere. These construction projects can range from small residential houses to giant skyscrapers or miles-long bridges.

Today, we will discuss ten of these construction projects in the world, which we consider as the largest of them all. These projects not only take up huge ground area, but they are also gigantic in scope, manpower and resource usage, economic and geographical impact, and they take quite some time to build. Some of these require very different kinds of technologies to construct, as you will see below. Our list of the top ten largest construction projects includes infrastructures, industrial, and entertainment complexes.

Al Maktoum International Airport, Dubai

Spreading over 21 square miles, the Al Maktoum International Airport is the largest airport under construction ever. While the construction has been scheduled to finish in 2018, it has been delayed indefinitely. The monstrous project will eat up $32 billion in the second phase only. When finished, the airport will be able to accommodate the movements and servicing of two hundred wide-body airplanes and other assorted aircraft at one time.

Jubail II, Saudi Arabia

One of the longest-running industrial projects in the world is Jubail II, running for over 22 years. It is an industrial city, comprising of over a hundred industrial plants, a desalination plant sized eight hundred thousand cubic meters, and an oil refinery capable of producing 350,000 barrels of oil every day. The grounds of this project will be crisscrossed with miles and miles of highways, railroads, and streets to connect it with the rest of the country. It has started the second phase of expansion worth $11 billion back in 2014 is scheduled to continue building till 2024.

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What is Self-Compacting Concrete and How is it used

Self-compacting Concrete, or Self-Consolidating Concrete, generally called SCC, is a fresh concrete that runs under its own weight and does not want external oscillation to undergo compaction. Constructors use SCC in the building structures where it is troublesome to use vibrators for the consolidation of concrete.

Why is Compaction Needed?

After the liquid or paste concrete is poured in place and should be left to set, it should undergo the compaction process before it starts to harden. Compaction or Consolidation significantly enhances the final strength of concrete and improves bonding with reinforcement. It also increases the abrasion resistance and overall sturdiness of the concrete. Moreover, this process decreases the permeability of concrete and helps to minimize its shrinkage and creep characteristics.

What is SCC?

The SCC or Self-compacting concrete is a form of concrete that can flow under its weight, and that does not need to go through a separate compaction process to fill and flow through heavy reinforcement areas.

SCC has more or less equivalent cement binders and water ratios as the standard concrete mix. However, the variations in the mix cause the SCC to produce a higher strength without vibrating the concrete by forming better bonds between the hardened paste and the aggregates and reinforcements. You can pour SCC into structures more than five meters tall because due to its characteristics the aggregates will not get segregated. The self-compacting concrete can also be poured faster than the regular mix.

What are the Materials in SCC Mix?

To give the concrete paste diverse properties, somewhat different materials ratios are used in the SCC mix. These are as follows.

Cement: Grade 43 cement is used in self-compacting concrete, which must meet the physical properties according to IS:8112 code. The following table will give a better understanding of the cement used in SCC

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Types and Uses of Bulldozers in Construction

Most construction projects need moving of a large amount of earth, soil, sand, rubble, and debris all the time, especially at the beginning of the project. For this purpose, bulldozers come in very handy in land-based construction projects. Today we will see what these powerful machines are and how they are used in the construction industry.

The phrase "bulldozer" comes from an amalgamation of the words 'bull' and 'dose'. The first word implies power, while the latter indicates a will to force something to happen. The first proper bulldozer in history was produced in 1923 by farmer James Cummings and draftsman J. E. Mcleod. But this was used for farming purposes only. Bulldozers saw construction uses by the 1940’s.

What are Bulldozers?

Bulldozers, or dozers, in short, are essentially tractors with a large blade mounted in front of them. The tractor helps push the blade around the ground. Perpendicular to the ground, the blade is a thick plate of metal, wider than the tractor behind it and sometimes even half as tall. Sometimes the dozers come equipped with a claw-like device attached in the rear called a ripper to loosen up the ground before pushing it around.

Mobility

The vehicles are generally mounted on tracks, which gives them excellent ground traction and mobility on rough unstable terrain. Some versions of bulldozers come with extra-wide "swamp tracks" to handle soft ground. Though in uneven terrain, the use of wheeled bulldozers is common too. These dozers are mounted on four articulated hydraulics-operated large rubber wheels, which gives the vehicle the ability to work on uneven terrain and also much better speed than the tracked versions.

The engines of bulldozers need to be very high-powered since they need to create a huge amount of energy to push heavy objects. Also, the same engine needs to power the often-used hydraulics system. Depending on tasks the engines of dozers can vary from 70 to 1000 horsepower.

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Best Calculators Construction Engineers are Using

The construction industry is near the top of the most math-heavy fields of work. Each project starts guzzling out numerical data right from the very beginning of the process. All that information needs to be calculated using the proper tools to produce the desired result.

Chances are, you have been using some basic calculator to help in this work. A standard engineering calculator can be found in most civil engineers’ bags. Worse, we see that in modern days people are using the calculators in their mobiles in this task. However, if you are a construction manager worth your salt, you would know that these generalized tools are pathetic when it comes to handling complicated building-related data. Wouldn’t you wish there were calculators custom-built for construction jobs?

Fortunately, there are. Today, we will look into a few gadgets built specifically to handle the computational needs in a construction project. These calculators support custom functions, fractional computing, unit conversion, and a lot of other stuff specifically needed for building construction managers and civil engineers. Some of these are portable devices and some again are mobile apps. The 5 most popular construction calculators are:

1. Construction Master Pro
2. Construction Calculator-Building Material Estimate
3. Jobber 6
4. C-Calc Pro
5. Materials Estimating Calculator

Construction Master Pro: The flagship of Calculated Industries general construction calculation tools line, Construction Master Pro looks like any standard scientific calculator in a nice solid shockproof casing at first glance. Look closer, however, and you will see a myriad of custom functions and tools ornamenting the keypad.

Covering a wide range of constructional computation activities, this device can calculate details of building to framing to concrete work. Not only measurements, but you can also use this device to calculate how much material you need for building a given structure, the volume in excavations as well as fillings, and even go as far as counting the number of transports and their costs for your project.

The Construction Master Pro covers unit conversion needs as well, and unlike a scientific converter it will not needlessly bog you down into unnecessary unit lists. It can convert to and from all building standard units like foot, meter, inch, centimetre and so on. Another advantage this device offers is the conversion of not only lengths but also areas and volumes.

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Types of Cranes Used in the Construction Industry

From as far back as the Mesopotamian civilization, cranes have been used for lifting objects that are too heavy or too repetitive to be done manually. Since this type of work is very much used in the construction industry, the use of cranes in it has been invaluable and indispensable since the ancient era. From the ancient Shadouf to roman Polyspastos to modern mobile telescopic cranes, they were used pretty much everywhere on earth.

What is a Crane?

A crane is a machine, comprised of beams, cables, and pullies, which is used to lift or lower heavy objects. An appropriately equipped crane may also move objects horizontally as well as vertically. The mechanism can be supported by a tower or a derrick.

Most cranes used in construction are temporary structures or even mounted on mobile platforms so that they can be moved around the construction site as necessary. They can be taken away when construction finishes in order to leave the site for normal usage. In some cases, where the building in question requires constant maintenance, the engineers may choose to rig a permanent crane with the building.

Modern cranes are powered by means of hydraulics that are driven by an electric motor or a combustion engine driven by fossil fuel. Operating (and driving, in case of mobile cranes) the crane is possible from an operators cabin that may be mounted on crane vehicle or rig itself, or a control station beside the crane, or by means of portable radio-operated controllers that gives the crane operator the freedom to move around and see the loading and unloading operation from any reasonable point of view. Taking that flexibility to a newer level, there are some modern cranes available that can even be controlled via mobile phone apps.

Types of Cranes in Building

Depending upon their usage, flexibility, and mobility, there can be several types of cranes to choose from to use in a construction site. The varieties of choices enable the constructor to adapt to any load-lifting requirements on site. Let us see what they are.

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November 2019 Brings Eight Top Construction Projects in US

This winter is snowing new building projects all over the US of A. From small houses and shops to major residential, offices, and retail we are seeing a lot of developments starting in the last couple of months. Especially, the last month, November 2019, has seen the start of a few major and important building projects.

We will highlight eight of the most important such projects today. These large projects are not only creating a lot of jobs, but also they are by their very nature can influence the market greatly. Their large volume and the need for sustainable enterprises mean they can and do seriously sway the total dollar and square footage volumes. Not to mention the amount of supporting industries that are required to make the project come about will see a major uptick for each of these projects.

Let us move on to the list of the most important 8 American construction projects starting in late 2019 without further ado.

1. Bankside Development Phase 1

On 21st November 2019, Brookfield Properties announced their opening of a mixed-use construction project along the waterfront in the South Bronx’s Mott Haven neighborhood. The project, named Bankside Development, is construed to be built in two phases, and this is the first phase only.

Spreading over the expensive 4.3-acre New York site, the project is designed to provide 1350 apartments. Though the area is for the higher-income parties, 30% of the total residentials will be under the Affordable New York program targeted for the lower-income bands. The apartments will have a permanently unobstructed view of the Manhattan area.

Divisionally located at 2401 Third Avenue and 101 Lincoln Avenue, the project is expected to end by late 2021. Hill West Architect designed seven towers in the project interconnected by low-rise elements. A new public waterfront park of more than 34000 sqft will frame the entire complex on the Harlem river shoreline, seeking to create a naturalized landscape with varieties of custom seating and an abundance of greenery.

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Five Reasons Why Off-site Modular Construction is the New Favorite

What is Off-site Modular Construction

Up until the last decade, we have always known construction business is to be conducted on project site. However, with the advent of technology, a new method of building has come up. This is called Off-site Modular Construction, and it is shaking the construction industry at the roots.

In this process, portions of a building are constructed in remote factories or fields that are specifically set up for that purpose. They are built using the same design and materials - but since they are being built in a factory for that express purpose, the construction takes about half the time. These “modules” are then carried off to the project site and are assembled there to reflect the original design of the entire project.

Growth in Modular Construction Business

There has been an increased demand for off-site modular construction, ever since the construction industry has rebounded up since 2013. Experts project that the market has progressed by 26% between 2014 to 2017.

An estimate is that the projected growth for the period 2018 to 2020 is by 4% every year. Such promising verticals can be associated with the resurgence in sectors such as education, offices, and retail. It is also a gift from with increased market for locality accommodation on infrastructure projects.

Architects, developers, and constructors are all gradually becoming aware of the plethora of benefits offered by technological innovations associated with the modular construction industry. From hotels, retail, offices, public buildings, apartment blocs to simple homes - all sorts of construction projects can be assembled with offsite modular structures.

This method of building is a favorable alternative to regular on-site construction, and it is durable and cost-effective. The main reason for that is the offsite modular building offers great quality and flexibility. It is also faster to finish the project with fewer expenses. Also, when it comes to counting the environmental impact and guaranteeing sustainability, there is no match for off-site construction methods.

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The Future of Construction with Robots

Robots make everything better, don’t they? Sure they do. The engineers and architects related to the construction industry think so as well. Construct-o-bots (or similar) have existed in science fiction forever. However, construction and architecture have been the least automated industries until recently. The nature of the work required to build a structure has always required a human mind to drive it, and the sheer number of steps to construct a simple thing and the varieties of tasks to be undertaken for a building translates into doing it manually. Over time, we have started to use machines for each step or task that can be automated or had to be mechanized, for example, concrete mixing, or pumping it far away. But to actually use Artificial Intelligence to make a simple wall has been impossible due to its intricacies. Well, up until now.

It is not like that construction work does not have scope for robotics and automation in it. On the contrary, there are plenty of jobs in a building site that are repetitive but not complex. Also, there are many occasions in a building site where humans would be in great danger. However manual labor has always been plentiful and heavy robotics hasn’t been making much headway until the last decade.

But we have come far indeed. From using pullies and mixing drums, we are now using cranes and dozers operated by joysticks or even by remote. New technologies are opening up new doors in modern constructions. Only in the last decade, we have seen various prototypes like robots to carry stuff, drones to survey, autonomous vehicles for transport, 3D printing for modeling, exoskeletons to augment worker strength and much more. Recently shortages of manual labor and low unemployment in the country are driving modern constructors to consider more mechanized solutions than ever.

Many tasks in construction can be taken care of by robots, including bricklaying, painting, loading, carrying, and bulldozing. In fact, in the transportation field, there are already many AGV’s (Automated Guided Vehicles) and AMR’s (Autonomous Mobile Robots) hard at work, and we can expect to see their numbers multiply significantly in a short while. There are three key factors that are driving the need for more robots in the construction industry. One, that robots can protect or replace human workers in a hazardous work environment. Secondly, increased usage of robots will decrease workplace injuries drastically. Not to mention that a gap in the manpower left by labor shortage can be filled by work bots.

There are already some incredible examples of machines driven by set data taking over large portions in the building sites. Today let us look at a few of some awesome examples of using robots in construction.

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Concrete Sweating: What is it and How to Prevent it

Concrete is used for all kinds of construction works these days. It is the first choice for building supports and beams because of its excellent load-bearing capacity, tensile strength, and longevity. However, nothing is a hundred percent impervious to weather effects, and neither is concrete.

Concrete Sweating, or more technically known as SSS (Sweating Slab Syndrome) occurs when water droplets are accumulated on the surface of a concrete structure. The phenomena occur generally overnight and may look like the concrete structure is sweating, hence the name. This can be a potentially dangerous issue in some cases.

Reasons for Concrete Sweating

There can be two main reasons why a structure is showing the SSS - dew point and subsurface moisture. Let us discuss them below.

Dew Point

When you take a soda out of the fridge and keep it out for a while, the soda bottle or can starts sweating. The same thing happens with concrete as well, especially overnight. A concrete surface is rather cooler than the air in contact with it. When the concrete is cooler than the dew point (the temperature at which the water vapor in the air starts to condense into liquid), the moisture in air sticks to the concrete. This, in turn, starts forming the water droplets. Which, to uninformed eyes, looks like as if the concrete has started sweating.

Subsurface Moisture

A much rarer phenomenon, this occurs when the concrete itself retains some moisture inside it. When the concrete is formed, much water is used to set the cement. All that water gets absorbed to form the crystals that harden the concrete. But the issue is, this process can go on for a long time. Initially, most types of cement can set in a day, but they harden over a long time - over weeks, even months. While the composite is hardening, the hydrostatic pressure inside them rises a lot. This, in turn, pushes the water out of the concrete slabs or structures. In this case, you can say that the concrete really does sweat, in view that the water comes from inside, not outside.

There can be some secondary reasons for SSS. For example, if the concrete slab is adjacent to wetness (wet soil or water body), the capillaries in a porous concrete can suck up moisture from the wet surface to the dry surface. Also, if the concrete mix has salts in it then due to their hygroscopic nature the salts will attract water into the concrete. The material on top of the concrete can also be the culprit in attracting water, like dust or rubber.

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What is Portland Cement and How is it Used in Construction

What is Portland Cement

The Portland Cement is a particular type of cementing material used in building construction. It is essentially an amalgamation of clay and chalk. This blend, when subjected to water, hardens up and when it is hard, mimics the portland stone in color. The Portland Stone is found in quarries in Portland, Dorset in England initially. This type of hydraulic cement was patented in 1824.

The portland cement is exceptional in giving strength to structural properties. Most commonly, it is used in making concrete. However, the portland cement can also be directly used in creating stucco or be used as a mortar. Some non-specialty grout also uses this type of cement as one of the main ingredients.

ASTM 150 defines the Portland Cement as “hydraulic cement (cement that not only hardens by reacting with water but also forms a water-resistant product) produced by pulverizing clinkers which consist essentially of hydraulic calcium silicates, usually containing one or more of the forms of calcium sulfate as an inter ground addition.”

How is Portland Cement Made

Usually created from heating limestone and clay minerals in a kiln, portland cement needs a little bit of gypsum in it to give it the desired setting qualities and to prevent flash setting. The chemical constituents of portland cement and their ratio are as follows:

1. Calcium oxide (61-67%)
2. Silicon dioxide (19-23%)
3. Aluminum oxide (2.5–6%)
4. Ferric oxide (0–6%)
5. Sulfur oxide (1.5–4.5%)
6. Gypsum (2-10%)

The Mix is generally a thin, light powder. Depending upon the ratio of materials in the clinker and the cement, this powder can be gray, white or something in-between. The most common form, called the OPC, displays a soft gray color. After hardening, it resembles the portland stones found in Dorset.

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How to analyze rate for brick masonry work

While analyzing the rate of brickwork, it is essential to ascertain the quantities of materials (bricks and mortar) and labors. There are different types of ratios for mortar which range from 1:2, 1:4, 1:6, 1:8 etc. Go through the following like to determine the quantity of mortar.

Estimating the quantity of bricks is necessary for the rate analysis.

Quantity Estimation for Brick Masonry - To analyze the rate of brick masonry, 1m3 of brick masonry is taken:

1. Number of bricks for 1 cubic meter of brick masonry:
For 1m3 of brick masonry, the number of typical size of bricks must be 494.

2. Quantity of mortar for 1m3 of brick masonry:

For 1m3 of brickwork, the quantity of the mortar should be 25 – 30%, i.e. 0.25m3 – 0.3m3 of cement masonry. For this purpose, cement mortar is selected as 0.3m3 .

Labor Estimation for Brick Masonry:
Labors which are essential for brick masonry belong to mason for brick work, labours for transmitting materials (sand, cement, bricks, and water), mixing and transporting mortar.

The quantity of labor is provided as requirement of labour in longer period for 1m3 of brick masonry.

1. Mason: The quantity of mason necessary for 1m3 of brickwork is provided as 0.94 days.
2. Labor: The quantity of labor for different types of works like carriage of materials, blending of mortar, carrying of mortar etc. are amassed. The labour necessary for 1m3 of brick masonry is for 1.57 days.

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Some useful tips to work out the cutting Length of Bent Up Bar In Slab

For a site engineer, it is essential to work out the cutting length of bars based on the slab dimensions and provided instructions to the bar benders.

If the construction work is intended for the small area, the reinforcement detailing can be transferred to the bar benders. They will deal with the cutting length. But be careful that it may not be perfect as they do not consider the bends and cranks. They may provide some additional inches to the bars for the bends which are fully imperfect. Therefore, to get rid of this issue, a site engineer should try to compute calculate the cutting length independently.

In this article, detailed explanation is given for working out the length for reinforcement bars of slab.

The calculation is made on the following dimensions :-

Diameter of the bar = 12 mm
Clear Cover = 25 mm
Clear Span (L) = 8000
Slab Thickness = 200 mm
Development Length(Ld) = 40d

Process for computation

Cutting Length = Clear Span of Slab + (2 x Development Length) + (2 x inclined length) – (45° bend x 4) – (90° bend x 2)
Inclined length = D/(sin 45°) – dD/ (tan 45°) = (D/0.7071) – (D/1)= (1D – 0.7071D)/0.7071= 0.42 D
There exist four 45°bends at the inner side (1,2,3 & 4) and two 90° bends ( a,b ).
45 ° = 1d; 90 ° = 2d
Cutting Length = Clear Span of Slab + (2 X Ld) +(2 x 0.42D) – (1d x 4) – (2d x 2) [BBS Shape Codes]

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Some useful methods for estimating building works

The following method are useful for working out various building quantities like earth work, foundation concrete, brickwork in plinth and super structure etc.

a) Long wall – short wall method
b) Centre line method.
c) Partly centre line and short wall method.

a) Long wall-short wall method: Under this method, the wall along the length of room is treated as long wall whereas the wall that is situated vertically to long wall is called short wall. To find out the length of long wall or short wall, initially compute the length of centre line for separate walls. Then compute the length of long wall, (out to out) once half breadth at each end is added to its centre line length. Therefore, the length of short wall is calculated into in and is built by subtracting half breadth from its centre line length at each end. The length of long wall normally declines from earth work to brick work in super structure whereas the short wall enlarges. In order to obtain quantities, multiply these lengths with breadth and depth.

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Some useful tips to design a T-beam with the use of limit state method

This construction video briefly describes how to create the design of t-beam with the use of limit state method.

A T-beam (or tee beam) is applied in construction extensively. It is a structural element developed with reinforced concrete, wood or metal. It contains a t-shaped cross section that is formed by a stem and a flange of reinforced concrete or rolled metal.

The top of the t-shaped cross section acts as a flange or compression member in withstanding compressive stresses. The web (vertical section) of the beam underneath the compression flange contributes to withstand shear stress and offer better separation for the coupled forces of bending.

A T-beam has the capacity to tolerate large loads by providing resistance in the beam or by internal reinforcements. It operates similar to singly reinforced beam.

In order to enhance the structural strength of a T-beam, just utilize an inverted T-beam together with a floor slab or bridge deck linking the tops of the beams. If it is accomplished perfectly, the slab performs as the compression flange.

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How to prevent segregation of concrete

Definition of Segregation of Concrete?
Major components of concrete are cement, sand, aggregate, and water. Normally, a coating is made to concrete aggregate with cement and sand for developing the consistent mass disjointing of these constituent materials of concrete from each other. It is known as segregation of concrete.

Type of segregation:

1. Partition of course aggregate from the paste.
2. Partition of course agreement paste from the concrete.
3. Partition of water from the cement mix which is also known as bleeding.

The segregation contains unwanted properties in the hardened concrete. It also leads to honeycombing in concrete. Segregation also adversely impacts on stability, compressive strength and all other characteristics of concrete. It also results in forming cavities in the concrete surface.

Reasons for segregation:

The segregation mainly occurs due to the variation in specific gravity and size of its constituent material. Specific gravity of water is 1. Specific gravity of cement is approx 3.15 whereas that of aggregate is 2.6 to 2.7. Because of the variation in specific gravity, lighter particle goes upwards and heavier particle goes downwards and consequently the segregation of concrete occurs.

Other reasons range from greater water cement ratio in concrete. Besides, when excessive water is added at the time of mixing concrete, it results in segregation. Improper vibration for a long period on wet mix of concrete also causes heavy material to setting down and lighter cement sand paste to move upwards. Imperfectly proportioned mix and inappropriate placing on site may also lead to segregation.

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Top 4 apps for civil engineering students

Civil Sutra: Civil Sutra is specifically created for the benefits of site engineers, site supervisor, contractors and Architects to supply crucial and useful information.

The app can be used for the following purposes :-

1. Quantity of concrete
2. Bricks quantity
3. Paint quantity

4. Mortar calculation for plaster
5. Unit Conversion Etc.

Civil Sutra can simplify the calculation and designing work with the use of standard tables and formulas. The civil engineers get rid of tedious manual calculation process on site and start automatic calculation with some simple clicks of the mouse.

Downoad (play.google.com)

My Civil CalC: This calculator can be used for rapid & precise unit conversion and calculation for area, volume, conversion with meter cube to meter feet, inch to mm etc.

It contains a unique feature of assigning measurement units feet-inch/ M/mm also with calculator to the input numbers and obtain the desired result together with the unit.

It is also possible to convert the calculated results to alternative units with different accessible converters at the bottom. It is very time saving and user friendly calculator toward the builders, civil engineers, architects, interior designers, estimators, contractors, billing engineers, store keepers. It also facilitates to covert the value with calculator.

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Published By
Rajib Dey
www.constructioncost.co
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