Permanent and Temporary Works at Construction Sites

Every day, millions of people work in various construction sites in our Country. By its very nature, a building or heavy construction site is not a safe place. There is always the danger of some accidents, dust and dirt, contamination, burning, hearing damage, and many other issues. So, let us see today how you can maintain your personal safety and hygiene in a construction site.

A. Eye Protection: There are lots of dust and small particles floating on air in a construction site. Some of them are quite damaging to your eye and retina. Therefore, you should always wear protective eyewear in a construction site. I mean actually wear them - not just hang them on your neck just because it’s a regulation!

Additionally, you have to wear special eyewear where welding is going on in a building site. The light of the welding is extremely bright. Looking directly at it can substantially damage your cornea.

Furthermore, you should take proper care of your eyewear. The eyes are a very vulnerable area of your body and they can get infected easily. For this reason, always clean your eyewear thoroughly before and after wearing it. Also, make sure the device is in proper working condition. Replace a damaged eyewear immediately.

B. Ear Protection: A construction site is always full of noises. There are cranes and other heavy machinery working, pumps and generators running, saws cutting steel, welding going on, and whatnot. For this reason, proper noise suppressing headphones are supplied to workers in such situations. Wear them! They are not just for show.

Many times, in widespread large construction projects, communication headsets double as protective earphones. This serves the team to stay in contact with the supervisors at all times and be protected from harsh, loud noise as well.

Sometimes, instead of using noise-suppressing earmuffs, the company supplies disposable earplugs. Do not reuse these! They get very dirty with all the earwax and they also absorb the oil. So, washing them is futile - they will still be dirty.

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Published By
Rajib Dey
www.constructioncost.co
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Some important terminologies in surveying and leveling

Leveling stands for the method of finding out the relative elevations of several objects or points on the earth's surface. It is performed by picking up measurements in the vertical plane. A leveling instrument known as ?Level? and ?Staff? is appointed for this purpose along with other equipments.

Given below, some vital terms in Surveying and Leveling :-

Level Surface: It refers to a surface that is normal to the direction of gravity at all points as stated by a plumb line. As for instance, the surface of a still lake can be a level surface.

Since the earth is an oblique spheroid, a level surface should not belong to a plane but should be a cursed one. The distance of each point on a level surface is equal from the center of the earth.

Level Line: A level line belongs to a line that is laid on a level surface. It is normal to the plumb line at all points.

Horizontal Plane: A horizontal plane through a point refers to a plane peripheral to the level surface at the point. It is normal to the direction of gravity at that point.

Horizontal Line: A line that remains at a 90 degree angle to the plumb line and tangent to a level surface is called a horizontal line.

Vertical Plane: A vertical plane belongs to any plane with a vertical line. A vertical line at any point stands for a line normal to the level surface at that point.

A plumb line is an instance of a vertical line.

Datum Surface: A datum or datum surface is the level of a point or the surface relating to which levels of other points or planes are measured.

Elevation of a Point: Elevation of a point is the vertical distance above or below the datum. This is usually called the reduced level (R.L) of the point. This may be positive or negative accordingly as the point is above or below the datum.

Line of Collimation: The line of collimation or the line of sight stands for the line that connects the junction of cross-hairs to the optical center of the object glass and its continuation.

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Published By
Rajib Dey
www.constructioncost.co
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Nature of Ground Movement Due to Earthquakes

Earthquakes are terrible natural disasters that occur due to movements in the tectonic plates. The ground moves due to the earthquakes. Since earthquakes can be gentle to violent, the ground movement can be marginal to devastating as a result. This moves the building vertically and horizontally, both of which creates considerable strain on the structure.

Of course, the exact magnitude of the shaking and shifting that a building experiences depends upon how far it is from the epicenter the the quake. Earthquakes create seismic waves that carry through the ground, and they weaken in power as they traverse the distance, finally getting completely absorbed.

The seismic waves travel faster through hard rock and slower through soft soil. However, when it transits from rock to soil, the strength of the wave increases. So, it really doesn’t matter whether you are on soft ground or hard - you will still be hit with considerable power, if you’re close to the center.

Understanding the nature of the waves generally occurring in a location gives rise to plans of how to combat it properly. This gives us knowledge and ways to construct a building properly so that common earthquakes cannot topple it.

There are different types of seismic waves, and they impact a structure differently. In general, they are broadly categorized into two seperate groups - body waves and surface waves.

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Published By
Rajib Dey
www.constructioncost.co
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Types of Foundations in Construction Industry

Today, we shall talk about the common sorts of foundations in buildings. Generally, all foundations are divided into 2 categories: shallow and deep. The words ‘shallow’ and ‘deep’ check with the depth of soil during which the inspiration is created.

Shallow foundations may be created in depths of as very little as 3 feet, whereas deep foundations may be created at depths of sixty – 200 feet. Shallow foundations are used for little, lightweight buildings, while deep ones are for giant, serious buildings. The following sorts of Foundations In Building Construction may be elaborated below.

Raft or Mat Foundations: Raft Foundations, conjointly referred to as Mat Foundations, are most frequently used once basements are to be made. In a raft, the complete basement floor block serves as the foundation; the burden of the building is unfold equally over the entire footprint of the building. it's referred to as a raft as a result of the building is sort of a vessel that ‘floats’ in an exceedingly ocean of soil.

Mat Foundations are used wherever the soil is weak, and thus building hundreds have to be compelled to meet an oversized space, or wherever columns are closely spaced, which suggests that if individual footings were used, they might hit one another.

Shallow Foundations: Shallow foundations are referred to as unfold footings or open footings. The ‘open’ refers to the very fact that the foundations are created by 1st excavating all the planet until all-time low of the footing, so constructing the footing. Throughout the first stages of labor, the complete footing is visible to the attention, associated is so referred to as an open foundation.

The concept is that every footing takes the focused load of the column and spreads it out over an oversized space,so that the particular weight on the soil doesn't exceed the safe bearing capability of the soil.

There are many forms of shallow footings: individual footings, strip footings and raft foundations.

In cold climates, shallow foundations should be protected against freezing. This can be as a result of water within the soil round the foundation can freeze and expand, thereby damaging the inspiration. These foundations ought to be engineered below the frost line, that is that the level within the ground higher than which freeze happens.

If they can't be engineered below the frost line, they must be protected by insulation: commonly a touch heat from the building can permeate into the soil and forestall freeze.

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Published By
Rajib Dey
www.constructioncost.co
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How to work out cutting length for column circular stirrups

This construction video is recorded to provide you some useful tips for estimating the cutting length of the circular column stirrups.

Here the radius of the column is taken as 400 mm.

Dia of stirrup is taken as 8 mm

Concrete Cover is taken as 40 mm

Stirrups are also known as Links or Rings or Transverse Reinforcement. Stirrups are applied in Beams and Columns. The stirrups remain vertical in a beam and horizontal in a column.

Benefits of column stirrups :
To settle and withstand the longitudinal (main) steel bars in columns to bulging below the vertical forces (compression force) particularly in the middle of the column prior to get to the concrete.

Increase the quantities (diameter or by spacing) of stirrups at both ends of the column with the intension of combating the horizontal forces which produce horizontal shear forces on both ends of the column.

Go through the following video, to get the detailed process.

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Published By
Rajib Dey
www.constructioncost.co
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Building Construction Work Sequence

A constructor needs to follow the work sequence carefully. Otherwise, the whole process of building construction might crash. Thus it is very important to maintain and follow the work sequence in building construction carefully. Let us see how it should be done properly.

1. Paper Work: The paperwork for the building needs to be finished even before the work actually begins. This includes:-

a. Preparation of drawings and diagrams
b. Material and construction cost estimation
c. Labor costs and contingency measures
d. Approval of design from local development authority
e. Any other legal work that may be necessary

2. Layout Marking: The plan boundaries need to be marked on the ground. Only the approved plan should be marked down. The ground inside and outside the site should be cleaned of any undesirable elements. Accurate dimensions and orientations must be followed while marking down the layout.

3. Excavation Work: The foundations of the building need to be placed under the ground level, onto a solid bed. For this, much excavation work needs to be done on site according to design. The wall foundations and column foundations may require different types of foundations. For this reason, different amounts of excavation may need to be done.Suitable machinery like dozers need to be used for large scale excavation. Not only that, you need to carry off the excavated earth to a suitable location as well.

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Published By
Rajib Dey
www.constructioncost.co
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What is Caisson Foundation and How is it Used in Construction

A Caisson Foundation is basically a watertight box with the top open. It is sunk into water to gain access to the bed of the stream. It is generally made of wood, steel or concrete depending upon project requirement.

Through this boxlike chamber, the workmen can make construction work at the bottom of water bodies without being hampered by the water. Accordingly, this is mainly used to place foundations at river beds.

Caissons are generally made on shore first. Then, They are launched into the water body. The caisson is then floated to the designated spot. Then they are sunk vertically to the bottom. After ensuring that the caisson is waterproof, the water inside is pumped out to dry.

Types of Caisson Foundation:

1. Box Caisson: This is the most basic type of caisson. It is made of timber, concrete or steel. It is built on shore and floated to the foundation location and sunk to the bottom. It is basically a box without the top.

2. Open Caisson: This type of caisson has neither the top nor the bottom. When made in a cylindrical shape, it looks like a well without top or bottom. It can be built in many shapes - vertical, over, or any other option.

In case of building large bridges, a bathtub-like shape is preferred. Usually open caissons are made of steel plates welded together. RCC can be also used here, as the situation requires.

3. Pneumatic Caisson: This odd type of caisson has an open bottom but closed top. This has to be forced down to the bottom of the water by means of compressed air. Thus the name is derived. A pneumatic caisson consists of a working chamber, a shaft, and an airlock. The caisson is made of inner and outer layer of steel skins. Trusses and girders join them to form a boxlike structure.

The working chamber in pneumatic caissons is 3-4 meters tall only. It is made airtight with a special seal on top. The caisson’s bottom edge has a steel edge that cuts into the riverbed. All this facilitates working within the chamber while the caisson is being sunk. People can access the caison via the airlock.

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Published By
Rajib Dey
www.constructioncost.co
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What are Shear Keys and How to Use Them

A building and structure has to bear not only vertical loads, but also lateral loads. This can occur due to many design or natural reasons. To counteract this lateral load, Shear Keys are used. Let us see today what exactly are shear keys and how can you use them in your construction.

A building can face a lot of lateral load due to many reasons. Some of these include earthquake loads, sliding forces, water pressure, wind pressure etc. This often occurs with bridges, retaining walls, basements, extremely tall buildings, precast buildings and culverts, masonry walls where seismic activity is stronger, and steel columns and piers.

Shear keys can be constructed by concrete in precast buildings, and of steel in steel structures. Sometimes, steel reinforcements are made to play the part of shear keys as well. They improve the lateral stability of a building.

Placement of Shear Keys: Where the shear keys will be placed differs a lot depending upon the structure they need to support. Let us discuss them below.

Bridges: In small to medium bridge structures, shear keys are placed in the abutments of the bridge. This provides lateral transverse support to the structure above during sidewise movement.

During an earthquake or similar strong lateral force application, the shear keys act as a sacrifice. Therefore, the strong seismic forces are prevented from entering the abutment piles.

They act better when they are placed on the outer side of the bridge. However, this makes them difficult to inspect or repair.

Retaining Walls: You should place shear keys at the base of retaining walls, just beneath the stem. This prevents sliding of the base during strong lateral force application.

The shear keys placed beneath the wall must be nearly twice in width than their depth for the best performance. Generally, they are 508mm by 381 mm, respectively.

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Published By
Rajib Dey
www.constructioncost.co
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What is Plane Table Surveying

Plane Table Surveying is used in ad-hoc surveying and designing situations. In this, survey fieldwork and plotting work is done simultaneously. Therefore, there is no need for office work. This is best adapted to situations where high precision is not required. Thereby, it is greatly useful for small-scale mapping operations.

Instruments used in Plane Table Surveying - The Plane Table survey method uses very simple instruments. These are available everywhere.

1. Drawing Board: It is a board made of seasoned wood. They are available in many sizes. Generally, the field work is done in 40 cm by 30 cm boards. They also use the 75 cm by 60 cm boards, for larger work. In the field, a tripod is placed under the board with a ball socket in it. This enables the surveyor to draw on the board from any angle.

2. Alidade: An alidade is basically a ruler with a telescope. This is used on the drawing board to draw lines and rays according to the field. The alidade may also have a spirit level on it.

3. Compass: A tough compass is used to find the magnetic meridian of the place. Generally, the compass used in survey work also has two bubble tubes at right angles to each other.

4. Plumbing Fork: It is a rod with a plumbob attached to one end. This is used to ensure that other equipment is aligned perfectly vertically, when needed.

5. Spirit Level: It is a tube of liquid with a bubble inside it. The tube is slightly bulging in the middle. This lets the bubble stay in the middle of the tube when the level is perfectly horizontal. This is used to make sure the drawing board, or other equipment are placed horizontally.

6. Waterproof cover: A waterproof cover is used to cover up the paper on the drawing board from rain or other splashes and dust. This is generally made of soft polythene.

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Published By
Rajib Dey
www.constructioncost.co
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Download some crucial civil engineering journals with most updated information

Go through the huge lists of civil engineering journals which are very useful for civil engineers to be updated with the most recent advancement in civil engineering fields.

The journals include original papers inside the extensive field of civil engineering which focus on the following topics :-

1. New triplet visions on sustainable building
2. Optimization of ground improvement techniques in tunnelling
3. Optimum mix for the geopolymer concrete
4. Partial replacement of sand with quarry dust in concrete
5. Performance of lightweight foamed concrete using laterite as sand replacement
6. Piezoresistive cement based materials for strain sensing
7. Properties of concrete by replacement of natural sand with artificial sand

8. Properties of concrete contain ultra fine ash
9. Properties of concrete with coconut shells as aggregate
10. Properties of concretes produced with waste ceramic tile aggregate
11. Properties of fiber reinforced polymer concrete
12. Properties of high-volume fly ash concrete incorporating nano-sio 2

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Published By
Rajib Dey
www.constructioncost.co
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Using Light Gauge Steel Frames in Construction

There is a new construction method on the market, and it is quite cool. Called the Light Gauge Steel Frame Construction, it is successfully replacing the standard wood frame construction method. This innovative method is being widely accepted in many building designs and construction aspects.

The Light Gauge Steel Frames offer several advantages. Some of them are design flexibility, strength, sustainability, buildability, etc. This makes Light Gauge Steel Frames easier to build and much safer too. Not only that, it is also faster to build. Word to the wise, though - the light steel frame is susceptible to fire, so fire protection coating needs to be provided.

Based on ASTM standard A1003, Light Gauge Steel Frames are manufactured from structural steel sheets. These sheets are formed into ‘C’ ‘Z’ and ‘S’ shapes. This makes the structure strong and able to support heavy loads. It is also called cold formed steel. This is because of the process by which it is manufactured.

This added strength and flexibility leads Light Gauge Steel Frames to support increased spans. They can be shaped into custom openings. Moreover, they can support many different types of external facade treatments. This sheer versatility is making the Light Gauge Steel Frames very popular among modern constructors.

One thing to be noted about Light Gauge Steel Frames is they are much more susceptible to corrosion effects than standard wooden frames. For this reason, they have to be provided with zinc, aluminum or combo coatings to make them corrosion-resistant over long periods.

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Published By
Rajib Dey
www.constructioncost.co
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External Plastering Work Checklist - To follow in Building Construction

The external plastering work in a building project is a pretty important work because it provides the outer finish of the building. Not only that, it is the foundation for the building’s aesthetics. For these reasons, every constructor should keep in mind some basic steps in order to do it right. As such, the following checklist can be very helpful in external plastering work in building construction.

1. Clean the surface: Make sure that the external surface of the building is clean. That means the block or brick masonry and concrete surface. These should be clear of dust, oil grease, loose materials, mortar dropping, nails, wood, metal strips, etc. You should have an even, smooth surface to work on. Otherwise the bonding will not work.

2. Make scaffoldings: You need to erect a scaffolding in order to reach the entire outside surface. Conversely, you might be needing a double scaffolding as well. You have to do this without making a hole in the wall. Since in this phase you must not damage the wall in any way. However, if authorities permit, you can take support from other parts of the building.

3. Mortar and socketing: The gaps between the masonry and the beams that show on the outside needs to be filled with rich mortar. Also, you need to finish out the socketing works.

4. Chicken mesh: Then, fix a chicken mesh on the joint of RCC and masonry wall. The mesh should be 6 inches wide. Nail this mesh at 230mm intervals only.

5. Plumb measure: Use the plumb (also the line) from top to bottom to ensure the accuracy of the plastering.

The plastering here should be of a single coat of 10-12mm only. Also, you must check all the edges.

6. Handle jutting out stuff: Sometimes, a beam or a column, or other parts of construction may be budging out of the plastering. In this case, first take approval of the designer to see if you can break it off. If you can, then use a sharp chisel or hammer to break off the jutting-out portion. Also, you can use a concrete breaker in this. Do take care that it doesn’t hurt any other part of the building.

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Published By
Rajib Dey
www.constructioncost.co
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How to avoid Honeycombing in RCC Structures

Definition of a honeycombing: Honeycombing refers to a structural fault in a RCC Structure. Honeycombed surface is the areas of the concrete surface where the coarse aggregate are eminently observable.

If precaution is not taken for honeycombed surface, the RCC structure fails to achieve optimal performance according to its design (structurally weak). Besides, it also lets damaging agents like contaminated water and air entering through the produced voids which can impact the strength of structure considerably.

Causes for Honeycombing: Honeycombing in RCC Structure is happened because of the following reasons -

1. Concrete mix is not homogenous.
2. The applicability of concrete is inadequate and not matched with its placement need.
3. Inadequate compaction to concrete.
4. Concrete flow is not dispersed to all corner due to steel congestion.

5. Concrete is set afore time prior to placing.
6. High free fall of concrete, at the time of pouring
7. Form work is not waterproof or inflexible.
8. Incorrect detailing and/or fixing of steel

How Honeycombing in Concrete can be avoided?

Check concrete production/cohesiveness from time to time to organize all concrete batches.

Tip: If it is possible to create ?ball? from the fresh concrete, a cohesive concrete mix is produced.

Concrete workability should tally with the placement need. As for example, a lightly reinforced column should contain 75mm slump, a heavily reinforced column may require 150mm slump.

Make sure that the compaction of placed concrete is perfect, vibrators should have been detached as big air bubbles stops to come out (over vibration can lead to bleeding). Various sizes (25mm, 40mm, and 60mm) of vibrator needle should have been utilized according to RCC sections.

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Published By
Rajib Dey
www.constructioncost.co
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