Types of Walls used in Building Construction

Wall is an auxiliary component which partitions the space (room) into two spaces (rooms) and furthermore gives security and a safe house. For the most part, the walls are separated as two sorts: external walls and inward walls. External walls give a fenced in area to the house for cover and internal walls assists with apportioning the nook into the necessary number of rooms. Internal walls are additionally called as Partition walls or Interior Walls and Outer walls are likewise called as Exterior walls.

In the specialized perspective the walls are isolated into the accompanying kinds:

Load Bearing Wall: As the name itself proposes, the entire structure is laid on walls rather than segments. When all is said in done, the loads from chunk moves to the bars, from bars to the sections and afterward spread to the establishment.

The structure has bars and sections however not segments. In basic words, regardless of whether it's outside or inside walls, the wall which is bearing the entire load of the structure, including self-weight of basic components is called Load bearing wall. Strip establishment is embraced for the load-bearing sort of wall.

Non-load Bearing wall or Drop Wall: This kind of wall doesn't bolster floor or rooftop loads above them which implies it wont convey any of the heaviness of the structure above it. Segment walls inside the structure are its best case, where these are developed uniquely to partition the rooms and these walls don't have any auxiliary respectability. The non-load bearing wall can be evacuated or abbreviated without influencing the structure.

Non-Load bearing walls are likewise called Drop walls or Filling walls. The thickness of on Load bearing wall for the most part lies in the middle of 100mm to 125mm.


~~~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~~~

The four types of Shallow Foundation

Shallow foundation is applied in cases where we can find good load-bearing soil at a rather low depth. The foundation depth must meet the safety requirements of the breakdown. That is, after the application of load, the complete structure settlement will be within acceptable limits.

We can use the following four types of shallow foundations: Spread Footing, Combined Footing, Raft Foundation and Ring Foundation.

1. Spread Foundation: You need to spread the load from the column or wall to a larger area, you should use Spread Foundation. The width of the footing area is much wider than the wall or column.

The spread footing that is used to support a wall is called a wall footing or continuous footing. The top of the footing may be stepped or tapered, increasing the width gradually from wall or column to the base. They are of the following types:

a) Strip Footing: This primitive type of footing has been conventionally used in most constructions historically, before more modern inventions. They are mostly made of stones, masonry or concrete. The strip footing that is constructed of stone blocks generally has a stepped top. In modern days, however, the use of strip footing has become next to obsolete. Only in some light loading residential construction is strip footing still used.

b) Isolated Footing: When you provide footings under columns separately in a framed structure, it is called Isolated footing, pad footing or column footing.

In most cases, square footings are used under columns. However, space restrictions may force you to use rectangular footings. In case of circular columns, circular footings may be used, though it is not common. It may be used in special circumstances where construction work is difficult, or the load has to be dispersed very equally.

2. Combined Footing: When two columns are too close to make separate footings for each, then their footings are combined. These may be of the following three types:

a) Rectangular footing: These are the most common types of combined footing. It’s basically two square footings constructed together. This is used when each column is bearing the same load and of the same size.

~~~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~~~

Construct Earthquake Resistant Buildings by Simple Means

The engineering science is continuing to advance in response to seismic threats. There have been significant breakthroughs in the field. However, most of them are very complex and require exceptional machinery. Not to mention, expensive as well. However, there are some simple ways to build a structure that will be resistant to earthquake damages up to a certain level.

In areas where seismic activity is not too harsh, we can utilize these techniques to same money and complexity but make the building resistant to seismic activities.

Structure Stiffness: The most traditional way to fight quakes is to use stronger materials to construct the building. Stiffer or heavier members can be used to fight the lateral forces generated during seismic activities. For special quake-proof structures, ACI codes prescribe at least 10” thick members.

Geometrical Absorption: The building can be planned in such a regular and special geometrical shape that it disperses the seismic forces evenly so that no particular member experiences excessive force. This naturally fares much better than a poorly-planned unsymmetrical building.

For existing buildings that are structurally asymmetrical, you can use seismic joints and expansion points in places where the forces are dispersed unevenly. Providing extra columns, shear walls, and framing can make the weaker section withstand the extra forces to a good level. Parking levels should have extra reinforced columns in order to negate the soft story effect.

Lateral Force Resistance: Using three types of lateral force resisting systems, we can try to negate much of the seismic forces. These are:

1. Moment Resisting Frame System: it is designed to resist all types of earthquake generated forces acting on the structure. They can be customized to fit the seismic activity scale of the region.

2. Building Frame System: these are designed to resist gravitational loads only, but they function excellently in that. A shear wall is added to resist the lateral forces acting on structure.

3. Dual Frame System: this is a combination of the above two systems. Shear walls along with moment resisting frames work excellently to fight off the vibrations and displacements from an earthquake. But, of course, they are more complex and costlier to build.

~~~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~~~

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.

~~~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~~~

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.

Read more

~~~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~~~

Pier foundation and their types, advantages

A pier is kind of a big brother to a column. It is a support structure holding up great loads, and can take a lot of tensile strains as well. Piers are constructed in a dry place by digging out the soil in a large diameter hole and then filling it with reinforcements and concrete. A pile greater than 0.6 meter in diameter becomes a pier.

The pier foundation transfers the load on the pier to the ground via the bearing. It is generally a shallow structure placed on top of sound rock layer. Hard soil is also good for pier foundation construction provided they can take the load.

Types of Pier Foundation

There are two main types of pier foundations, namely:

1. Masonry or concrete pier
2. Drilled caisson

Which type of pier foundation will be used depends upon the depth of the hard bed, nature of soil, and the superimposed load.

Masonry or Concrete Pier Foundation

The name comes from the pier being made of concrete. Precast sections are manufactured in-situ or in facility. Then they are driven into the ground at location. The sections are generally reinforced with steel wires. At the bottom, a cast steel shoe is provided to hold the structure better and to transfer the load well. The cross sections of these piers are generally no more than 30-50 centimeters and they are no taller than 20 meters.

Drilled Caisson Pier Foundation

A drilled caisson is a large compressed member subjected to an axial load. The load is at the top and the reaction is at the bottom. These can be concrete caisson with enlarged bottom, a steel pipe caisson with concrete filled in it, or a concrete body caisson with a steel pipe core.

Read more

~~~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~~~

Relocation of Structures

Sometimes, it is required to move a building from one place to another location. This can be required for a number of reasons, like change of land, replanning of facility or even natural causes. In such situations, a process called Structure Relocation comes into play.

Relocation of a structure essentially involves three steps. The first is to disassemble the existing structure - you need to tear the building down systematically, preserving as much material and objects as you can. The second step is transporting the disassembled building blocks to the intended target location.

This may need the involvement of heavy transport support if the location is far away. Of course, if the location is within the same property then this step reduces next to zero. The last and the most important step is to reassemble the building back again at the target location using the same building blocks from the previous structure and maybe some extra materials.

Sometimes if the building is small enough and light enough, it can be picked up as a whole and transported to the new location with minimal disassembly and reconstruction necessary. If the move is within the same piece of property, the move can be done by rolling it on temporary rails or rollers. For long distance moves, generally heavy-duty flatbed trucks are used. Though in that case many complications may arise on the way, like roadside obstacles like narrow zones, and overhead obstacles like low-hanging branches and cables.

Read more

~~~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~~~

Standards of Reinforcements Detailing in Slabs and Beams

Reinforcement Detailing in Slabs and Beams performs a vital role in a construction process to provide durability and strength to the structure. It also helps out in the cost optimization for the project. A structure’s cover to reinforcement, length of the reinforcement, it’s curtailment, number and diameter should all be clearly defined by the detailing of the reinforcement of the concrete beams and slabs.

Consider a generic concrete slab or beam, supported via simple means. This structure would experience the maximum bending moment at the center of the span. The shear force will come at a distance of d/2 from the face of the support (where d = effective depth of the slab or the beam).

This indicates clearly that the bending reinforcement is required at the center of the span, where the bending moment occurs, not at the support. Whereas the support should be reinforced to withhold the shearing forces.

Therefore, it would not be necessary to cover the full length of the structure in tension reinforcement. In fact, as much as 50% of the reinforcement can be curtailed at suitable locations. They can also be repurposed as shear reinforcements by bending them upwords.

Read more

~~~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~~~

Basic differences among foundation & footing

Foundation: It is the portion of a building that is built up underneath the ground level and keeps direct contact with sub-strata. It transfers the complete load of the building to the subsoil in which it stands in such a manner that settlement of the soil is not collapsed in shear.

Footing: It is the bottom most part of a vertical structure (column, wall) that finally transmits the weight from walls and columns to the soil or bedrock.

Footing is mainly the segment of foundation of any modern structure.

Variation among footing and foundation

Given below, the basic variations among Footing and Foundation:

1
The footing is a formation that is in touch with the ground.

Foundation belongs to a structure that transfers its gravity loads to earth from superstructure.

2
Footing is analogized with the feet of the leg.
Foundation is compared with legs.

3
The footing refers to a type of shallow foundation.
Foundation is both shallow and deep.

4
Footing comprises of slab, rebar which are made of brickwork, masonry or concrete.
Foundation types comprise piles, caissons, footings, piers, the lateral supports, and anchors.

5
Footing reinforces support to a separate column.
Foundation stands for an extensive support since it provides support to a group of footings as a whole building.

6
A number of footings rest on a foundation.
Foundation is the support that sustains different types of loadings.

7
A footing remains under the foundation wall.
Foundations stand for the basement walls.

8
Footing directly transfers loads to the soil.
Foundation is directly related with the soil and passes it on the ground.

9
All footings are foundations.
Not all foundations are footings.

Read more

~~~~~~~~~~~~~~~~~~~~~~~~~~

Published By

Rajib Dey

www.constructioncost.co

~~~~~~~~~~~~~~~~~~~~~~~~~~

Factor of safety for soil bearing capacity

Factors of safety for bearing capacity refers to a value that is based on the basis of the type of soil, method of exploration, level of uncertainty in soil, significance of structure and outcomes of failure, and probability of design load proceeding.

So, it creates adequate space to adapt uncertainties and potential over loading throughout the duration of the structure and its foundation through the cutback of ultimate bearing capacity of soil to permissible bearing capacity.

The permissible bearing capacity is measured by dividing ultimate bearing capacity with factor of safety. Normally, a factor of safety of (3) is presumed for bearing capacity calculations, if not mentioned for bearing capacity problems.

Bearing capacity means the strength of soil to bear the pressure securely that is provided on the soil from any engineered structure devoid of experience a shear failure with accompanying large settlements. Applying a bearing pressure that is secured with regards to failure does not guarantee that settlement of the foundation will remain inside tolerable ranges.

So, settlement analysis should normally be accomplished since most structures are sensitive to extreme settlement.

In the following table, you will get the standard factor of safety for bearing capacity calculation in different conditions. These factors of safeties are conservative and normally limit settlement to suitable values, but economy may be abandoned in some cases.

Factor of safety chosen for design is based on the extent of information obtainable on subsoil characteristics and their variability. A detailed and wide-ranging subsoil investigation may allow use of smaller factor of safety.

Read more

~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~

Some useful construction tips to provide clear cover for reinforced concrete structure

This construction video tutorial will provide detailed guidelines on how to provide perfect clear cover in reinforcement concrete structure.

With the intension of safeguarding the reinforcement from corrosion as well as arranging fire resistance to bars implanted in concrete, clear cover is set for Reinforced Concrete Structures.

Clear cover stands for the distance among C.G of reinforcement bars and bottom most point of concrete.

The thickness of cover is dependent on ecological conditions and nature of structural member.

The depth of concrete cover is calculated by applying a cover meter.

The clear cover that should be provided is determined by Indian Standards. IS 456:2000.

Watch following youtube video to learn the complete process :-

Read more

~~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~~

How to study column footing drawing for a structure

This construction video offers detailed guidelines on how to check column footing drawing.

Footings stand for structural elements which deliver the loads of column or wall to the elementary soil underneath the structure. Footings are built up to disperse these loads to the soil devoid of surpassing its safe bearing capacity, to resist enormous settlement of the structure to an acceptable limit with the purpose of reducing differential settlement as well as withstanding sliding and overturning.

The settlement is dependent on the depth of the load, nature of soil, and foundation level. If there is differential settlement, the different footings have to be designed in such a manner to settle self-reliantly of each other.

Foundation design comprises of a soil study to set up the most suitable type of foundation and a structural design to find out footing dimensions and necessary amount of reinforcement. As the compressive strength of the soil is normally much weaker as compared to the concrete, the contact area among the soil and the footing is much bigger with regard to that of the columns and walls.

Read Continue

~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co

~~~~~~~~~~~~~~~~~~~~~~~~

Some useful construction tips to provide clear cover for reinforced concrete structure

This construction video tutorial will provide detailed guidelines on how to provide perfect clear cover in reinforcement concrete structure.

With the intension of safeguarding the reinforcement from corrosion as well as arranging fire resistance to bars implanted in concrete, clear cover is set for Reinforced Concrete Structures.

Clear cover stands for the distance among C.G of reinforcement bars and bottom most point of concrete.

The thickness of cover is dependent on ecological conditions and nature of structural member.

The depth of concrete cover is calculated by applying a cover meter.

The clear cover that should be provided is determined by Indian Standards. IS 456:2000.

Watch following youtube video to learn the complete process :-

Read more

~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co

~~~~~~~~~~~~~~~~~~~~~~~~

Reasons for failure of bearing capacity on foundation

Foundation failure occurs due to variation on the load:

There exist three types of shear failure, i.e. General, Local and Punching shear failures which happened due to the compactness of soil and depth of footing with regard to its breadth (i.e D/B Ratio). When the utmost capacitybearing  of the soil is attained, it may fail in one of the following three failure type on the basis of the type of soil and depth to width ratio of the footing. A foundation can collapse in the following three diverse ways under loads :

Punching shear failure of foundation

General Shear Failure of foundation

Local shear failure of foundation

The above three types of foundation failure should be examined throughout design phase of concrete foundation for the specified load. Directives obtained through standard codes of practice should be obeyed so that foundation does not fail in any of the failure types as stated under any probable load combinations when structure is in use.

1.General Shear Failure

• Under this type, the footing moves downward slightly and thus forms completely plastic zones and a sudden failure occurs with a significant bulging of the ground surface alongside the footing
• It is based on clear-cut failure pattern, that comprised of a wedge and slip surface and bulging (heaving) of soil surface alongside the footing
• Sudden collapse happens, together with tilting of the footing
• This type of failure happens provided that dense sand or stiff cohesive soil support the footing
• Failure load is apparent
• The load-settlement diagram is equivalent to stress-strain for solid sand or over-consolidated clay
• The ultimate load is apparent on this curve.

2. Local shear Failure:

Failure pattern comprises of wedge and slip surface but is transparent only under the footing. Slight bulging of soil surface takes place. Tilting of footing is not necessary.

• In this mode a large deformation takes place under the footing prior to the formation of failure zones, i.e. large vertical settlement occurs prior to slight bulging of the ground surface
• Tilting of footing is not necessary
• Ultimate load is not clear
• It occurs in moderately compressible soils or loose sand i.e occurs in soil of high compactness
• Yielding occurs adjacent to the lower edges of the footing
• Various yield developments may happen together with settlement in a series of jerks
• The bearing pressure at which the first yield occurs is assigned as the first-failure pressure or first failure load

Read more

~~~~~~~~~~~~~~~~~~~~~~~~

Published By

Rajib Dey

www.constructioncost.co

~~~~~~~~~~~~~~~~~~~~~~~~

How to measure the quantity of asphalt in road construction

This construction video shows the detailed process for measuring the quantity of Asphalt in road.

Asphalt belongs to a blend of aggregates, binder and filler. It is mainly applied for developing and preserving all kind of roads, parking areas as well as play and sport areas. Various types of aggregates like crushed rock, sand, gravel or slags are utilized as mixtures of Asphalt. A binder is applied with the purpose of fastening the aggregates into a solid mixture. Generally, bitumen is utilized as a binder. An average asphalt pavement comprises of the road structure over the formation level that contains unbound and bituminous-bound materials. So, the loads of the traffic are dispersed through the pavement earlier it reaches to the formation level. Generally, pavements are formed with different layers.

Here, the dimensions of the road are given as follow :-

Breadth = 8 meter
Depth of the road = 15 centimeter
Length = 2 km = 2000 meter
Therefore, the volume of asphalt = L x B x W = 2000 x 8 x 0.15 (15 cm = 0.15 m) = 2400 m3

Here, density of asphalt is taken as 2330 kg/m3
Therefore, quantity of asphalt = volume of road section x density of asphalt
= 2400 x 2330 = 559200 kg = 5592 tons (dividing by 1000)

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

~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~

Details of Deep Foundation

A deep foundation means a type of foundation that disperse building loads to the earth more distant down from the surface, what a shallow foundation perform, to a subsurface layer or a range of depths. A pile refers to a perpendicular structural element of a deep foundation, directed or drilled deep into the ground on the building site.

Deep foundations are set up too intensely under the finished ground surface because of their base bearing capability that can be influenced with surface conditions. It is generally remained at depths >3 m under finished ground level.

Deep foundation is designed to bear loads from a structure via frail compressible soils or fills on to robust and less flexible soils or rocks at depth, or for functional reasons.

If, the strata of good bearing capability does not exist adjacent to the ground, the foundation of the structure should be rooted deep to facilitate obtaining a bearing stratum that is appropriate in all respects.

Besides, there are other conditions for which deep foundations are essential for the consistency and longevity of a structure. Generally, the deep foundations are essential for the various types of constructions like piles, caissons and basement or hollow box foundation.

Piles

A pile refers to a long cylinder of a solid material like concrete that is digged into the ground to provide a strong support for structures constructed on top of it.

Pile foundation is useful when the structure can’t resist load due to low & insufficient bearing capacity of soil. This happens because of the soil condition or the order of bottom layers, type of loads on foundations, conditions at site and operational conditions. Pile foundations are formed with wood, concrete or steel and can be either precast or cast on site in case of concrete.

To gather more information, visit civilengineeringdaily.com

~~~~~~~~~~~~~~~~~~~~~

Published By

Rajib Dey

www.constructioncost.co

~~~~~~~~~~~~~~~~~~~~~

Use of Excel Spread Sheet by a Quantity Surveyor for Material Stock Taking

This video will provide you use of Excel Spread Sheet by a Quantity Surveyor for Material Stock Taking On-Site.wmv.

We provides accurate material takeoffs for some or all phases of Construction including elevation plan, concrete foundation, site concrete and cast-in-place concrete both for private and public biddings. We generate accurate quantity take-off from plan sheets on any structure in spite of size.

~~~~~~~~~~~~~~~~~~~~~

Published By

Rajib Dey

www.constructioncost.co

~~~~~~~~~~~~~~~~~~~~~

Watch The Live Demonstration Of SEMA Timber Construction Software

SEMA timber construction software is created on the basis of a modular structure and it is useful for small tradesman, carpenters and joiners, as well as by large-scale wood-working centres and manufacturers of pre-fabricated houses.

SEMA timber construction software can be applied for creating superior quality roofs and houses. It includes free floor layout plans and roof input options to simplify the process for creating the design of any timber construction.

There are an extensive database comprising interchangeable dynamic component libraries for generally applied timber and steel components together with several constructional details.

It is possible to generate company or project specific standards all through the design phase and save & use them for other projects.

SEMA comes with quick and smooth component definition with special processing and all the essential automatic features to compute the walls aptly.

Intermediate walls can either be generated as cogged log walls or like conventional walls involving timber-framed walls, lightweight walls etc. The adaptable corner macros simply fit to such mingled constructions.

With our efficient master data technology and its sophisticated automatic features, All the layouts & drawings are instantly generated as per needs of the customer through superior master data technology and its automatic features.

SEMA provides a widespread collection of timber fasteners and brackets out of all eminent manufacturers with respect to the standard master data. All the related information for material evaluation is consolidated and the requisite processing of the components is automatically formed.

To deal with any complicated construction, there exist comprehensive libraries with adaptable 3D processing like cuts, notches, drillings and much more are accessible.

Your design gets better with pre-set plan layouts with separate title blocks. The printout is ’live’ from the 3D object as all the modifications are automatically updated in all views instantly.

View the following online demonstration

~~~~~~~~~~~~~~~~~~~~~

Published By

Rajib Dey

www.constructioncost.co

~~~~~~~~~~~~~~~~~~~~~

Mix Design On The Basis Of Dry Condition

Ascertain or Identify Slump Value

The initial step is to identify the lowest and highest limit for slump of concrete that has been utilized. Often the designer identify slump for concrete mix, this is correctly based on some conditions, otherwise if the value of slump is not indicated Table 1 is applied to find out the lowest and highest slump value on the basis of the type of structure.

Note: The value of (Table 1) is dependent on applying vibrator for compaction of concrete, if there is other method for compaction like a tamping by rods or other method add (2 cm) for every selected value from table 1.

Step 2: Ascertain or State Maximum Aggregate Size

Highest Aggregate Size is considered as the most vital data to be ascertained or identified for their mix design. This value is acquired from sieving analysis test result of coarse aggregate. Coarse aggregate must be examined prior to utilize in concrete mixture preparation. This value is accessible even for comprehensive mix design process.

Value of Maximum Aggregate Size must be examined with the following three equations:

(a): Highest Aggregate Size must be identical or lesser than 1/5 (lowest distance among form work side).

(b): Highest Aggregate Size must be identical or lesser than 1/3 (thickness of concrete member).

(c): Highest Aggregate Size must be identical or lesser than 3/4 (slightest distance among reinforcement).

Note: Point (c) is very vital in checking process as if the aggregate size exceeds the spacing of reinforcement while casting, concrete fails to pass the rebar cage. It signifies that passing ability of concrete is considerably reduced.

To read the complete article, visit ge4c.com

~~~~~~~~~~~~~~~~~~~~~

Published By

Rajib Dey

www.constructioncost.co

~~~~~~~~~~~~~~~~~~~~~

How to determine zero force members in truss structures

This construction video provides useful information on how to make solution for zero force members in a truss. The video is very useful for the students who will appear in PE exam.

Occasionally in truss structure, under specific loading configuration, there exist some members that do not bear the load. These members are defined as zero-force members and generally utilized to enhance the strength of truss as well as deliver future supports when the implemented loading configuration is modified. The method of inspection is applied to define these zero-force members. Under this method, every joint in a truss structure is analyzed one by one.

Given below some useful tips to determine the zero-force members in truss structures:

• If a joint contains only two members without any external load or support, then those two members belong to zero-force members.

• If a joint contains only two members and is loaded, then when the line of action of consequential force from applied loads at the joint lies in the same straight line with one of the members then the other member belongs to a zero-force member. If the consequential force at the joint is not lying in the same straight line with either member, then both members do not belong to zero-force members.

• If a joint contains members without any external load and/or support, then when two of the members are lying in the same straight line then the non-collinear member belongs to a zero-force member.

In brief, zero-force members are detectable at a joint containing two members with or without applied load(s) and at a joint containing three members in which there does not exit any applied load. The objective is to focus on the specific joint being examined.

~~~~~~~~~~~~~~~~~~~~~

Published By

Rajib Dey

www.constructioncost.co

~~~~~~~~~~~~~~~~~~~~~