Kinds of Bonds used in Brick Masonry

Bonds are like the arrangement or bricks to strong the imaginable interlocking and stop the flow of the vertical joints that can be done in various ways.

About Bond

Bond is the arrangement of either bricks or stones in every course, so to ensure the greatest imaginable interlocking and to escape the flow of vertical joints in two successive courses; both on the face and in the body of a wall. Generally brick bonds are used in masonry work and these bonds are like patterns in which bricks are laid and it can be applied in both brick walls and paving; besides that it also used to concrete block and other kinds of masonry construction.

Objectives of Bonds

A bond is given to achieve the following objectives-

• The main objective is to provide a bond is to break the flow of the vertical joints in the serial courses both in length and thickness on masonry framework which will act as a bounded mass and its weight will be transformed uniformly to the foundations.
• Secondly it can ensure lengthwise and sidelong strength of the structure.
• It also provides comfortable appearance by laying bricks regularly.
• It can do the masonry stuffs fast by captivating more masons on a job at a time.

Types of Bonds

The types are divided as per laying and bonding style of bricks in walls and the bonds in brick masonry is increased by the mortar filling between layers of bricks and in channels when bricks are laid near to each other and in layers in walls. In brick masonry the most used material is cement mortar; line and mud mortars are also used sometime. Here is the list of the types of bonds which are used in brick masonry:

• Stretcher Bond

longer narrow faced brick is called as stretcher and this bond is known also as running bond which is created in the time when the bricks are laid with only their stretches, overlapping midway with the courses of bricks below and above. They come with the simplest repeating pattern but the limitation can’t make effective bonding with near bricks in full width thick brick walls. These bonds are generally used in the steel or reinforced concrete framed structures as outer facing and in cavity walls, boundary walls, gardens etc. Walls built with stretcher bonds are not enough strong to stand alone in longer span and height and need supporting structure like brick masonry columns at normal intervals.

• Header bond

Header is the shorter square face of the brick measuring 9cm * 9cm and the header bond is known as heading bond where all the bricks in every course are placed as headers on the faces of the walls. This bond is used for the construction of walls with full brick thickness measuring 18cm and the overlap is similar to half width of the brick.

• English bond

It has only one course of stretcher and a course of header above it where headers are laid centered on the stretches in course below and every alternate row is vertically aligned. Quoin closer is used in the beginning and the end of a wall after first header to break the flow of vertical joints and a quoin close is a brick cut lengthwise into two halves and used at corners in brick walls.

• Flemish bond

it is also known as Dutch bond and is created by laying alternate headers and stretchers in a single course and the next course of brick is laid such that harder lies in the middle of the stretcher in the course below. The thickness is minimum one full brick but the problem of using it is that it need to be aligned vertically for best effects and they are weaker than English bonds for load bearing wall construction.

• Facing bond

in this bond, the bricks are arranged for thick walls where facing and backing are needed to be constructed with bricks of different thickness and the bond has heading and stretching corners nicely arranged.

• Dutch bond

it is a change of the old English cross bond and has alternate courses of headers and stretchers; here the bricks are arranged in a form where every stretching course start at the quoin with a three-quarter bat and the alternate stretching courses has headers placed next to the three-quarter brick bat given at the quoin.

• English cross bond

it is like English bond and is very strong to bear a good elevation where queen closer are beside the quoin headers.

• Brick on edge bond

It is like English bond but the stretcher courses are replaced by laying the brick on the edges and header courses lay on the beds.

• Raking bond

The bonding bricks are arranged in any angle which helps to improve the longitudinal strengthens of thick walls made in English bond.

• Zigzag bond

It is like herring bone bond but the difference is that the bricks are laid in a zigzag style that used in brick paved flooring.

• Garden wall bond

it is very much adopted for one brick thick that can act as a garden wall or a boundary wall and for garden wall bond; it is possible to build uniform faces for a wall without much labor or expense and is very strong also.

Source: www.slideshare.net

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Published By

Rajib Dey

www.constructioncost.co

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Some information about Floor Screed

Floor screed is a type of building material used in construction to make the floors smooth and flat, the screed made with right quantity of cement and sand.

Introduction

It is a building material that is made from a 1:3 or 1:4.5 ratio of cement with sharp sand and can be applied in both solid-in-situ concrete ground floor slab and onto a formed concrete floor unit. This screed can be directly mixed to the base or laid uncombined onto a fitting damp proof coating which is laid over the slab and also be applied as a floating finish over a layer of firm padding of material. It is best to use with cast-in water pipes to give underfloor heating; they sometime left unfinished or floated to create a smooth surface upon which the specified flooring will be done later.

Some factory mixed the sand and cement to create the screeds and then deliver it to the site with additional quality assurance over site mixed screeds with more firm material. There are some manufacturers in the market, who made pumpable flowing screeds that flows to the last level of finishes and they are anhydrite compounds based on a calcium sulphate binder which can be applied faster than normal screeds in a minimum thickness.

So mainly floor scared is the foundation of the floor finish and immensely influences the work of floor finish; this article will show the different types of floor screed depending on some points that are:

• Type
• Material
• Requirements
• Procedure
• Construction

Types of Floor Screed

There are many types of floor screed which are based on the needs, applications and the functionality of the floor like

• Unbounded screed floor
• Bonded screed floor
• Floating screed floor
• Heated screed floor

Materials for Floor Screed

The screed is dependent of some materials which are used in the time of mixing and they are- Cement, Clean and Sharp sand, Water and sometime accessories are added to know some properties like Polymer materials or metal mesh or glass. All these components are sufficiently mixed as per the prepared material proportions and if the thickness doesn’t match then the proportions will be changed; it is important to know that after drying the proportions will be reduced.

Requirements that a Floor Screed should meet

The floor screeds must have right thickness as per the screed type and application rates and the thickness is dependent on the type of the screed floor and the provided construction conditions.

• The strength of the floor screed has to be 20MPa for domestic application and 30MPa for industrial usage.
• The screeds have to firm and thick enough to provide right base to the floor finish.
• It also e curried well to avoid shrinking and fast drying that causes cracks; that’s why it must be tested under all the shrinkage to prevent the cracks.
• Beside all the above qualities, the surface of the floor screed has to be flat and smooth.

Procedure of Floor Screeding

• Judging the surface of the base
• Calculate materials that are used for screeding
• Create the base and floor screed mixture
• Using bonding agents
• Place the floor screed mixture
• Also properly cure the placed materials

Constructing a successful screed floor

• Always select right and adjustable floor screed mixture
• Then select right screed floor type
• Now make right and fitted floor screed mixture
• Then construct the floor screed with appropriate screed placement process
• Choose right ways for floor screed protection

Source: www.theconstructor.org

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Published By

Rajib Dey

www.constructioncost.co

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The causes affecting the Degree of Earthquake damages to buildings

High rising buildings generally fall when the earthquake hits them and cause utmost destruction or damage with a loss of lives and the fall depends on several reasons.

Earthquake is really a destructive natural destroyer that is destroying some towns and cities continuously over the centuries and damaging them. This destruction for earthquakes can happen upon some conditions of ground or construction based mostly on sediments in flood plains, converted land or former landfill grows the effect of the vibrations though the harder rocks prevent the shaking amount. The result of the effect can be seen in a huge devastated way like damaging of lives and buildings and animals etc. in some cases the land may even dissolve like quicksand and make buildings sink.

Poor construction can make buildings more vulnerable for the earthquake damage and where the bricks have been held in place with the right mortar will survive long. Besides the construction, there are various other factors that are responsible for the damage of building for earthquake and they are breakable columns, stiffness elements, expandable ground floor, short columns, shapes, sizes, numbers of storeys, kind of foundation, location of the buildings, structural layouts etc.

Here all the above cause of damages is being discussed to give a clear overview of the problems and damages and the factors are also stated those can improve the degree of earthquake that damages the buildings. The factors are:

Difference between design and actual response range

Wrong measurement of excepted earthquake characteristics are used in the earthquake design of the form is both popular and difficult reason for the damage of the buildings.

Breakable columns

Most of the structures have been failed in earthquake as per the failure of column and the column may fail for decline of concrete that made cyclic loading and less number of ties fixed in the column at the important locations.

Irregular arrangement of hardness element in plan

Cores in structures are the main stiffness element and its location as building would influence the behavior of the structures when earthquake affects and make damage.

Adjustable ground floor

If the stiffness is decreased heavily of a structure then the stress falls on the structural elements of increased story may increase and fail.

Short columns

This reason is not very much familiar in comparison of ordinary column failure yet short column may fail in cutting in heavy manner and also make the structure fall.

Shape of the floor plan

It is said that the square shaped floor plan is the best insecure behavior than other shapes so the extent of building insecure damage is made by the floor shape plan.

Shape of the building in height

The normal upper storey have most insecure response capered with buildings which have upper storyes in the form.

Slabs support columns without beams

Flat slab system is the weakest structural system which does not have any good resistance against seismic effects and those system is very flexible and has low flexibility

Damages happen by previous earthquake

There are many buildings that have faced earthquakes previously and can face earthquakes again and will fail if the repairing had not done well. It is also seen that repairing a long ago can cause same damage though the methods have improved and the effects are also.

Strong concrete building with a frame structural system

this system is actually a base of weakness in buildings as it goes through many inter-storey drift by seismic excitation which needed more cost to repair.

Number of storyes

When the storeys number increases the chance of affected by earthquake gets high, high rises buildings’ storeys don’t have the strength to bear the capacity of the building.

Foundation types

The types of foundation raises the degree of earthquake damages in two forms – direct and indirect; for direct effect of foundation form it clear itself in number of characteristics and the failure of foundation member is rarely happening but leaves effect. On the other hand, the indirect one has out of plane movements of individual columns based in the case of isolated foundations.

Place of the connected buildings in the block

The location of the connected buildings on block affects on the structure and increases the fail of the buildings.

Slab levels of near structure

The impulse loading from adjacent buildings have a significant influence on the increment of the damages ; the increase of damages in structures with various floor level slabs are significantly greater than buildings with the same floor slab level.

Bad structural layout

The poor adjustment between architectural engineer and structural engineer at conceptual design phase can make bad structural layout.

Source: www.theconstructor.org/




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Published By
Rajib Dey
www.constructioncost.co
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Designs with raised Foundations in the flood likely area

Building plans are most important for creating a worth dream house that will be flood resistant and beautiful, but also have open spaces and areas for everyone.

Construction Industry is a difficult and risky area to perform the jobs on time, as while making buildings the contractors or builders have to face various kinds of problems like weather problem, natural disaster and the problem created by men or law etc. It becomes more difficult when any area deals with various kind of natural disaster such as flood or earthquake related areas where the buildings have to be more stable.

Architects and designers are continuously trying to find a kind of structure for home that will be firm enough to handle every kind of natural calamity. Here are some examples of the building designs that are made for the flood related area:

Easy does it

The Chatham Home Planning, Inc. has made a design of a simple and open costal cottage that has outdoor living options on the two levels including a veranda, deck downstairs and a private balcony for the upstair master suit; besides that there are private bathrooms, dual walk-in closets and two lavish bedrooms. The other level also has walk-in closets as downstairs and on the main floor there is a big kitchen nearby the open dining room with a beautiful fireplace in the living room. In addition of the two bedrooms, there are two more bedrooms sharing a hall bath attached with laundry.

The Suite Life

Visbeen Architects has designed a unique drawing where every bedroom is a suite in a breezy gateway and the main level has a large open dining room with a large table and entrances a deck on the one side. The big suite lodges on the same level and also has two decks and one of them is private; the upper one has a big space for family and friends get together. There is a sitting area on the landing that offers the great view which is the peace of mind.

Elevated Living

The design of Donald A. Gardner, Inc. provides an elevator in the house providing more comfortable to the people, the elevator starts with the storage level and goes all the way up to the top level where the two bedrooms give with a beautiful view. The main gathering space has a latest open layout with a seamless flow outside the balcony. The placement of the cooktop on the island makes it easier to talk with everyone while cooking, while the master suite includes a private balcony and a super-handy connection to the laundry room.

Relaxing on the Porch

A simple home design with separate bedroom layout that keeps all the living spaces on an equal level and has an elevator to go everywhere. The kitchen space has seating area for three people with close presence to the big room and open dining area; people can have their work in the studio or can step out to the back porch stretching straight from the beautiful master bedroom.

Source: www.builderonline.com

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Published By

Rajib Dey

www.constructioncost.co

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Virtual Construction Monitoring with NavVis

The Construction industry is a slow adapter of technology now needed a huge speed in the process to get faster improvement and NavVis has many upgraded products.

About Virtual construction Monitoring

Construction industry is the slowest of all the technologies to adopt any kind of technology especially in Indian background and today’s construction work is much different from the previous ways. So the problems are also happen for various reasons such as lack of need, innovations, aptness of new local conditions, no cost advantage, less awareness about the work process, obstruction to change and many more. All over India, the speed of work technology has been taking the place and it is necessary to accept new inventions and technology to make sure cost upgradation, high quality standards and timely end of projects with the reduction of time wastage with limited resources used in construction.

So to fulfill all these demands using a tool is important which will be a big discovery in the construction industry in recent times which can provide lots of advantages to all the parties in the project such as project owners, investors, consultants, contractors, vendors or end users. Basically Virtual construction is nothing more than completing a construction project in a computer with every kind of material and information as like it is done in reality on the ground. So this type of virtually constructed model is available in most of the problems that can be faced in construction project would now be done in advance that will save both time and cost.

Besides the above benefits other benefits that can get form the virtual construction is:

• Right bill of quantities estimation
• Well arranged and clash free shop drawing production for construction
• Automated input to CNC machines
• Project monitoring as per cost and time

NavVis has developed a 3D scanning and imaging solution that is beneficial for the clients and builders in any construction project and any where they work and for the 3D scanning of interiors. The device has three wheels, six cameras, there laser scanners and sensors for capturing the point clouds, panoramic images and location data. The device can be handled easily, user just need to push the M3 Trolley into the spaces where it is need to scan and then the system will do the rest process. It is shown that with this device a man can scan up to 30000 square meters of spaces per day and can get a perfect, deep visual model of the interior of the building.

About NavVis

The NavVis company was established in the year of 2013 and was a research project in the past time and after that the workers worked a lot of on the technology to make it solid and capable to be the future helper of the construction industry. Besides the M3 Trolley, there are two other NavVis products named 3D visualization software and vision-based indoor positioning technology which make the big amount of special usable data. The newest NavVis product has appeared as a navigation technology that can be added into any previous or new developed app to navigate large or complicated building and can be used in Wi-Fi, Bluetooth, image recognition or locating the user’s position indoors. It is building an ecosystem of building owners, mapping partners and solution partners. NavVis provide open interfaces for application development and is a member of SAP PartnerEdgeecosystem. They have many partnerships also like Zynca BIM from Sweden, Allthings from Switzerland and Clove Technologies from India.

Visual Construction Management

IndoorView is a browser based user interface to the point clod of NavVis which can read the point- cloud data not only from the M3 Trolley but also takes data from other devices like drones or hand scanners. With the help of this NavVis product, a contractor and scan the site on a daily basis and edit the visual models with either comments or other information which is called upgraded feature of the IndoorViewer. In addition of that, it can also integrate the model data with project management or other software; contractors can track project progress every time and share images with exact location in the building. Basically it gives an exact visual record of a project that helps the contractor to do changes or rectify the problems.

To gather more information, go through the following construction Software aec-business.com

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Published By

Rajib Dey

www.constructioncost.co

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Detail lists of useful construction tools

Given below, the detailed lists of various useful construction tools and their applications :-

Hoe – It is effective for digging and arranging concrete, cement mortar in head pan. Hoe is also useful for excavating the soil but here the metal plate is set with acute angle to the wooden handle.

Head Pan – It is utilized to transmit materials. Head pan is built with iron to uprise the excavated soil or cement or concrete to the construction site etc. it is mostly found in construction sites.

Masonry trowel – The objective of this tool is to organize cement mortar. It refers to a hand trowel that is applied in brickwork or stonework for the purpose of leveling, dispersion and shaping mortar or concrete.

Measurement Tape – It is employed to examine the thickness, length, widths of masonry walls, foundation beds, excavated trenches etc.

Plumb Bob - It is applicable for verifying the vertical alignment of the structures. It comprises of a solid metal bob attached with the end of a thread. It can also be applied in surveying to level the instrument position.

Wheel Barrow – It is useful for carrying out cement mortar or any materials. Often, it is utilized to estimate the quantities of materials for site level concrete mixing.

Concrete Mixer – It is a machine that is used for blending the concrete perfectly with water, fine aggregate, coarse aggregate and cement at construction site.

Vibrator - It is utilized to vibrate the concrete when pouring is started. For the purpose of workability, water is added to concrete. To get rid of that, vibrators are applied.

Bump Cutter/Screed – The objective of this tool is to level fresh concrete surface particularly in slab concrete.

Wooden Float/wooden rendering float - This tool is useful for providing a flat finish to the plastered area.

Crow Bar - This tool is found in formwork to eliminate nails from boards. Crow bar is also applied for digging the ground and taking out the roots of trees in the ground, nails etc.

Framing Square - This tool is mostly found in Brickwork, Plastering to verify exact angle.

Line Level - This tool is required to verify horizontal level in brickwork, plastering , flooring and tile works.

Flat Pry Bar - This tool is found in shuttering and often utilized to modify the column formwork to align.

Digging bar - This tool is used to divide and unloose the compacted / hard surface area. Digging bar refers to a solid metal rod having pin shape at the bottom. It is also utilized to dig the hard surfaces of ground.

For more information, go through the following link www.civilology.com



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Published By
Rajib Dey
www.constructioncost.co
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Specific Gravity & Water Absorption of Coarse Aggregate

This construction video tutorial is useful for concrete mix design. This video tutorial is based on specific gravity and water absorption of course aggregate.

Different types of apparatus like weighing balance, thermostatically controlled oven, glass vessel, enamel tray, air tight container, 10 mm IS sieve, sample are required for this purpose.

The following methods are used :-

Sieve the sample with the help of 10 mm sieve to eliminate thinner particles and then select 1 kg sample. Set the sample in a glass vessel and load the vessel partially with water.

Retain the sample for 24 hours in order that these are fully soaked.

After completion of 24 hours, load the vessel entirely and cover the vessel by disc to resist entrapping of air into vessel. Dehydrate the vessel from outside. Now measure the weight.

Weight of vessel with disc + water + sample (A) = 3372 gms.

Discharge the water of vessel. Now aggregates are set on a dry cloth unless it comes in SSD (surface saturated dry) condition. Now take the weight as C = 990 gms.

Now load the vessel fully with water. Cover the vessel with disc so that no air can enter into it. Now, again take the weight.

Weight of vessel together with disc and water (B) = 2574 gms.

Now, put the SSD sample in a tray made of enamel and retain it in oven at 1000C for 24 hours. Once 24 hours are completed, let the sample cool in air tight container.

Now, take the weight of the oven dry sample as D = 982 gms.

The following formula is used to determine the specific gravity :-

D/C-(A-B), here, A denotes weight of vessel with disc + water + sample = 3372 gms
B denotes weight of vessel with disc + water = 2754 gms

C denotes weight of SSD sample = 990 gms
D denotes weight of oven dry sample = 982 gms

To determine water absorption, use the following formula :-
C-D/D x 100 = 990 – 982/982 x 100 = 0.81%

To get more detail information, go through the following video tutorial.



Read more

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Published By
Rajib Dey
www.constructioncost.co
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