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Friday, September 22, 2017

How to find out the required amount of concrete for construction work

To find out the exact quantities of concrete for a construction project is very crucial. Given below, some useful tips for computing the quantities of concrete mix for any construction project.
How to work out the amount of concrete necessary for Slabs(along with odd shapes)
Rule of thumb: Include 1/4" to the density of your slab for your slab concrete budget. It supposes that the job is uniformly graded to the exact depth, and the grade is properly compacted.
While examining your grade, if it is found that one spot is 4" and other spots are 4.5" to 5" then it is recommended ion to settle the grade for both the job quality and your concrete budget.
Odd shapes: Convert odd shapes into rectangles and odd shapes can be located easily.
Build driveway 14' x 20' and your estimate will be perfect. It will be done in this way - The driveway is 16' at the top and 12' at the bottom. Throughout the center the width averages 14'.
Working out the Amount of Concrete Essential For Footings
Footings will seldom pursue the drawing accurately. In the soil where there are lots of gravels, the footings may fall down if big rocks are excavated.
It is assumed as a 12"*12" footing, but check how the left side of the footing has fallen down. Compute the exact width.
The digging is too deep by the excavator, or there may be raining and the digging for footings should be deeper to get to solid soil. Therefore, it is vatal to examine different types of spots on your footing and obtain an average size. Then with the help of a calculator, works out the required amount of concrete.
House slabs on grade that are 8" out of grade containing a 4" slab also arranged some of the footing over the grade too.
This 12" x 12" footing should be computed as 12" x 16" so the footing is built to go over grade to attain the 4" slab thickness.
To make calculation online, click on the following link
How to find out the required amount of concrete for construction work

Published By
Rajib Dey

Thursday, September 21, 2017

5 Methods of Calculating Quantities of Materials

There are many methods used for calculating quantities of materials. Which one goes with your plan depends on the design and shape of the building. Each method is characteristically different from other.

Calculation of quantities of material needs a proper technical understanding of materials and construction. The five major methods are described here for you and they come up with the right measurement of materials you need.

1. Centre Line Method: Centre line method is applicable to the square building with symmetrical offsets. To calculate the quantities of materials, you need to multiply the total centre line length with breadth and depth of the construction.

The centre line length will be reduced by half of breadth of every junction where the main wall is joined with the cross walls, partitions or verandah. The junctions must be taken into consideration while calculating the centre line length of a wall. The quantity estimation brought out by this method is accurate and fast.

2. Crossing method: Crossing method is designed for calculating materials needed for masonry walls. In this method, the lengths and breadths of walls at plinth level (the base on which a column is raised) are included. The internal dimension of the room and the thickness of the walls are also important to calculate the quantities. Symmetrical offsets should be counted as they play a major role in the calculation of quantity of materials.

3. Out to out and in to in method: This method follows P.W.D system for computing materials and this seems to be the most accurate method among all.

4. Bay method: This bay method is applicable in garages, factory, and railway platform where identical structures are visible. Bay in a construction term means a compartment of a building. The cost of one room is calculated first and it is multiplied by the number of bays.

5. Service unit method: The term service unit method is designed for building with identical rooms. This method is applicable in the construction of college, hospital, cinemas, prison, and more. When it is a construction of a hospital, the service unit will be a bed. Likewise, for cinema/stadium, it is seats.

Calculating quantities of materials follow the above-mentioned methods. Each of which shows a different perspective of calculation and they are also concentrated on different construction types.

5 Methods of Calculating Quantities of Materials

Published By
Rajib Dey

Wednesday, September 20, 2017

How to choose pile foundation on the basis of cost versus other foundations for construction project

Get detailed information on how to choose the pile foundations on the basis of cost vs. other foundations for construction projects and factors which impact the cost of pile foundation.

Sometimes, it becomes difficult for structural designer to take stable decision to select types of foundations like pile foundation or ordinary strip or mat foundation to be used for the structure.

The problem becomes acute while going to choose among pile foundation and traditional mat or strip foundation developed in a deeper level to fit a soil layer having desirable bearing strength.
There should be an indicator for all construction conditions under which the use of pile foundation is considered as inexpensive with reference to traditional strip and mat foundations.
This article will focus on the variations through which the decision for choosing of pile foundation over other foundation types can be taken without difficulty. This condition line is formed on the reasonably detailed cost appraisal of the foundation. The foundation cost is impacted by the following factors :-
Factors impacting the cost of Pile Foundation
Evidently, final decision for employing the type of foundation, cannot be taken on the basis of the calculation of excavation volume and concrete quantity of deep mat or strip foundation with regard to cost of piles that support the same load.

A cap is needed for Pile foundation. The density of the cap should be approx 45cm for two piles and 60cm to 120cm for two pair of piles. Plan dimensions of piling cap should be up to 2100mm2 for pile having diameter of 550mm.
With tie beams provided over one direction, the Pile caps are joined together using tie beams in more than one direction.
It is found that, the excavation cost of pile cap along with capping beams and tie beams is two times the cost of machine excavation in moderately large column bases. With the advancement of construction, the perfect structural design as well as stringent supervision is required for pile foundation.

To get more details, click on the following link

How to choose pile foundation on the basis of cost versus other foundations for construction project

Published By
Rajib Dey

Tuesday, September 19, 2017

The role of a quantity surveyor in construction sector

Liabilities of a Quantity Surveyor: A Quantity Surveyor (QS) is a professional who mainly deals with construction costs and contracts associated with the Construction Industry. The role of a quantity surveyor is to recognize and compile the related costs with the purpose of creating a complete budget for any project.

A quantity surveyor can then accept cost planning to facilitate all the members of the design team to find out the practical solutions and maintain the budget of the project.

The Quantity Surveyors along with the project architect produce this final detailed estimate to make a basis on which consequent tenders are examined. With schedules of quantities, it becomes easier to translate the drawing, plans and specifications submitted by the design team to facilitate the each contractor to work out the tender prices reasonably. Once tenders are approved, the Quantity Surveyor arranges cash flow data for the client to outline his resources sufficiently to fulfill contract commitments. Alternatively, the Quantity Surveyor has to settle on how much of a job should have been paid for at any one time.
Duties of Professional Quantity Surveyor - A Professional Quantity Surveyor (PQS) should accomplish the following works:
Produce and assess construction and development tenders out of information submitted by the architects, engineers and other design consultants as well as settle and reward contracts to successful proponents..
Handle, supervise and organize all types of construction and development projects, along with the contracts and sub-contracts, construction progress schedules, cost control systems, and work measurements.
Arrange, submit and control progress invoices, valuation of changes and settle contracts. Give suggestion on construction cost and strategic planning to potential owners, architects, engineers and public authorities.
Arrange and interpret tender documents, specifications, general conditions, and other parts and forms of contracts.
Create and deliver estimates for construction and development work.
Give suggestion commercially and support to construction and development project works.
Perform or take part in arbitration and court hearings. Research, negotiate and support dispute resolution operations. Function of a Construction Estimator Certified professional.
A Professional Quantity Surveyor contains a thorough knowledge of construction and construction methods together with the laws regarding construction projects and accounting, with the intention of providing cost and financial advice.

A Professional Quantity Surveyor should have specialty in mechanical or electrical disciplines, but all Professional Quantity Surveyors should possess working knowledge of the practical facets and design features of both fields.

Published By
Rajib Dey

Monday, September 18, 2017

Benefits of Engineered Cementitious Composite (ECC) in Concrete Construction

The objective of engineered cementitious composites is to develop a robust and flexible material that can be utilized in various purpose where fiber reinforced concrete can’t be used. It is the newest concept.
The formation of cementitious materials with high ductility is useful for structural applications. The engineered cementitious composites contain properties of high strength concrete having improved tensile strain capacity.
Definition of Engineered Cementitious Composite
The components of engineered cementitious composite are identical to fiber reinforced concrete along with cement, sand, water, fiber, and a few chemical additives. Contrasting to the fiber reinforced concrete, the engineered cementitious composites do not contain huge volume of fiber.
The method for blending engineered cementitious composites is equivalent to that utilized for the normal concrete. The engineered cementitious composites are cost-effective as less fiber is applied and they retain the desired characteristics of strength and ductility.
The main variance in the properties of engineered cementitious composite and fiber reinforced concrete is that as soon as the engineered cementitious composite is cracked strain is solidified whereas the fiber reinforced concrete does not demonstrate such a behavior.
In fiber reinforced concrete, the crack forms with the crack of the fibers because of that the bearing strength of the stress is reduced. Besides, the engineered cementitious composites contain a high fracture toughness that has similarity with aluminium alloys, and the damage tolerance is tremendously high.
Usage Of Engineered Cementitious Composite
Engineered cementitious composites are utilized in shear elements which are dependent on a cyclic loading, in the mechanical components of the beam and column coalition, and for general structural repairs.
These composites are generally applied in structures which contain a high energy absorption, along with dampers, steel element joints and for hybrid steel connections.
Beside, structural applications, these compounds can be utilized as a shielding layer for enhancing the corrosive resistance of structures. Other probable targets of engineered cementitious composites contain underground structures, highway pavements, and bridge decks.
To learn more click on the following link

Published By
Rajib Dey

Friday, September 15, 2017

Curtain Wall Design Tips For Water Penetration & Condensation

Designing curtain walls to water penetration brings huge benefits for maintaining the security, thermal performance and comfort of the structure and residents.
The rain caused by wind and condensation create huge issue and it becomes complicated to handle when curtain wall is designed together with gravity, kinetic energy, capillary action and surface tension and the chances are enhanced for water ingression.
Get the detailed information on the design of curtain wall against the infiltration of water and condensation.
Design of Curtain wall for Water Infiltration and Condensation
• Wind driven rain and the possibility of water ingression
• Design of curtain wall to control water penetration
• Design of curtain walls to control condensation
Wind driven rain and possibility of water ingression
There are five different types of forces such as that contribute either partially or as a whole to the ingression of water may occur due to existence of five various types of forces like gravity, kinetic energy, capillary action, surface tension and air pressure difference.
The curtain wall is capable of resisting forces that enhances the chance of water penetration. It is dependent on glazing details, drainage details, frame construction, weather stripping and frame gaskets, perimeter flashings and sealings and interior sealants.
Wind loads create differentials pressure that may cause windblown rain. It exceeds gravity force and as a result forces water to stir ascending.
Surface tension properties and capillary effect of curtain wall elements are significantly impacted with thermal expansion of various building materials.
As for example, expansion or contraction of materials because of temperatures may tight expansion joints extremely and ultimately raise capillary action among different components of the curtain wall.
The surface tension properties of curtain wall may fluctuate because of contraction and expansion and bring about unwanted results. So, it is necessary to design movable joints, seals and gaskets to accommodate differential movements among various members.

To learn how to make design of curtain walls to manage water penetration, click on the following link

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Published By
Rajib Dey

Thursday, September 14, 2017

Different types of bearings used in bridge structures

Bridge bearings stand for structural equipment or devices which are set up among bridge substructure and superstructure with the purpose of transmitting the functional load together with earthquake loads; wind loads; traffic loads; and superstructure self-weight.
Bridge bearings also allow for relative movements among superstructure and substructure, as for example, rotation movements and translational movements in horizontal and transverse direction.
Bearing is employed in building up the bridge structure. It is categorized as expansion bearings and fixed bearings. The first one allows for both translational and rotational movements while the second one allows for rotational and limited translational movements.
There are several types of bridge bearings which are frequently utilized in bridge construction. The details are given below :-
Various types of bearings for bridges: Sliding bearings, Rocker and pin bearings, Roller bearings, Elastomeric bearings, Curved bearings, Pot bearings, Disk bearings
Sliding Bearings for Bridges: Sliding bearing is made of two metal plates, generally stainless-steel plates, which slide corresponding to each other and therefore allows room for translational movement and lubricating material among them.
A friction force is produced in sliding bearing and it is enforced on substructure, superstructure and sliding bearing itself. So, it is necessary to arrange lubricant like polytetrafluoroethylene (PTFE) to reject generated friction.
As per guidelines by ASSHTO, the bridge span should be less than 15m to use sliding bearing in bridge structures. It is due to sliding bearing is not fully applicable if there is rotation movement in bridge.
While using sliding bearing, this span limitation can be avoided if it is employed in conjunction with other bearing types.
Rocker and Pin Bearings for Bridge Structures: Rocker stands for an expansion bearing that contains curved surface at the bottom. It adjusts translational movement and a pin at the top takes rotation movement into consideration.
Both rocker and pin bearings are vital parts of steel bridge structure. Rocker and pin bearing are taken into account when the bridge movement is suitably known and defined, because such bearings can allow for both translational and rotational movements in one direction only.
These bearings are susceptible to deterioration and corrosion, so inspection and maintenance should be performed on regular basis.

To get further details, go through the following article

Different types of bearings used in bridge structures

Published By
Rajib Dey

Wednesday, September 13, 2017

Some vital points a site civil engineer should abide by

Least density of the slab should be 125 mm.
Absorption of water should not be over 15%
Lapping is unaccepted for the bars which contain diameter over 36 mm.
Longitudinal reinforcement should be not under 0.8% and in excess of 6% of gross C/S.
At least 4 numbers of bars should be used for square column and 6 numbers of bars for circular column.
Minimum density of the slab should be 125 mm.
Lap slices are not recommended for the bar greater than 36 mm.
Water absorption of bricks should not surpass 15%.
PH value of the water should not be under 6.
Dimension tolerance for cubes should be +2 mm.
Densities of different types of construction materials :-
Steel = 7850 kg/Cum
Cement = 1440 kg/Cum
Brick = 1682 kg/Cum or 1920 kg/cum
Sand = 1100 to 1600 kg/cum

To get these information online, watch the following construction video.

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Published By
Rajib Dey


Tuesday, September 12, 2017

How selection of construction site is dependent on the various factors

Before starting the construction work of a residential building, the proper consideration should be given on the following factors to choose the exact site for the building.
Topography, Nature of sub-soil, Position of the ground water tablem, Facilities, Neighbourhood, Undesirable things near the site, Vegetation, Shape of the site, Availability of men and materials, Proximity to sea-shore, river or lake or the place of natural beauty
Topography: Plain Grounds : If the site is plain, the process for marking, excavation and construction becomes easier without any leveling. But the problem may arise for drainage. Besides, dull pools will be developed after a deep shower. In dry weather, outflow of septic tank develops pools and various diseases will be spread out due to mosquitoes and other insects.
Slopping Grounds : A bare at least of 1% (1 in 100)slope is essential for smooth drainage. At least 2% slope should be maintained for the drainage of lawns. Slope is easily visible, if it surpasses 5%.A ground that is properly leveled contains 0% slope but it is not perfect for construction whereas a slope among 3% and 10% is mostly recognized for constructions. Smooth erosion is possible along these slopes after a deep shower and creep (downward sliding of the subsoil)is generally occurred.
Undulating ground : After proper leveling, construction can be built up on undulating ground.
Low lying area : A low lying area is not recommended. Low lying area next to water body as a lake, reservoir, tank, river or canal may come with a nice view and arrange a superior comfort in severely chill and scorching climate.
Nature of sub-soil : If a soil contains strong bearing strength, a permanent building can be easily developed. The soil that remains underneath the ground is known as sub-soil. The soils which have gravel and sand are called dry soils. These soils cause greater temperature and less humidity.
The position of ground water table : Ground Water Table (GWT) should be located at minimum depth of 3 m underneath ground level.
Percolation : Soils percolating at 180 s/mm are correspondingly less porous and pooling of waste water is generally found in them.
Facilities : Community services like street cleaning, fire protection and utilities like gas supply, drainage line, transport system should have been easily accessible without incurring any additional cost.
To gather more details, click on the following link

Published By
Rajib Dey

Monday, September 11, 2017

Guidelines to follow for acceptance criteria for concrete

As per IS 456 : 2000 (C1 15.1), it is known that 28 days compressive strength shall individually be the standard for approval and disapproval of concrete.
But as per IS 456 : 2000 (C1 16), there exist two criterion for acceptance of concrete that range from compressive strength and flexural strength.
Prior to arrange test results for acceptance criteria, it is necessary to examine validation i.e. whether the sample is proper or improper for acceptance criteria.
The test results should be as follow :-
Test results are average of three specimens.
Individual deviation should be under ± 15% of the average.
Suppose M25 grade of concrete is applied in the construction. Let strength of specimen for first one should be 28.5 MPa (Mega Pascal). For the second one, it should be at 26 mega pascal and for third one, it should be 29 mega pascal.
By summing up, we get the average as 27.83 MPa (mega pascal).
If the individual deviation is computed from the average for first specimen, it shall be 2.4%.
For second, it shall be -6.57%
For third, it shall be 4.20%
From the test result, it can be said that the specimens are legitimate for acceptance criteria as the deviation of individual sample does not surpass 15%.

To get more details, go through the following video tutorial.

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Published By
Rajib Dey


Friday, September 8, 2017

Calculation of Cement and Sand Quantity for Plastering

The ratio and all calculations given below are according to the requirement of 12mm thick plastering.
Plastering, as we all know, removes imperfection of external walls along with maintaining the line level and the alignment. Generally, plastering is defined as a protective surface for walls. It can be many a type depending on the materials it uses such as cement plaster, gypsum plaster and lime plaster. These are the common types of plastering that are required for home construction.
Cement plaster has two main materials in its core – cement and sand. The right proportion is required to get the best outcome you expected. This plaster removes imperfections from both inner and outer walls of the construction. Knowing the right proportion is an important factor in the making the paste or mortar perfect for the walls.
The list below contains the ratio between cement and sand that you need to maintain as per the application.
• Cement mortar ratio 1:3 - this mortar mix is not used in general applications. It can be used as a repair mortar when they are combined with a waterproofing or bonding agent.
• 1:4 – for ceiling and external plaster.
• 1:5 – the ratio proved to be good as brickwork mortar. It is also good for internal plaster.
• 1:6 – this ratio can be maintained for internal plaster.

 Calculate Cement and Sand Requirement for Cement Plastering:
Calculating the quantities of cement, sand and water depends on a few parameters. These bring out the logic why you need to maintain the ratio.
• Volume of plaster requirement: the volume of plaster can be calculated by multiplying the area of the plaster and the thickness of the plastering (in this case – 12mm)
• Mix Ratio of plaster: deciding the Mix Ratio of plastering contains complex calculation. It indicated the ratio of the volume of cement to sand. Mix ratio of plaster 1:4 means that the mixture has one part cement and 4 parts sand.
For calculating quantity, generally two methods have been applied –DLDB method and Empirical method. These two processes include steps required for a logical distribution of the materials. The calculations and measurements used in this methods based on the quantity of the materials.

For further discussion, read

Published By
Rajib Dey

Thursday, September 7, 2017

EMMA calculator for measuring electrical quantities

A generic 'EMMA' for work with bulk electrical quantities.
A multi-use EMMA should be applied for any 'mass' activity, that entails a physically quantifiable unit of construction work scope measured in tens, hundreds or thousands. As for instance, electrical cable tray or racking or cable laying/pulling are perfect individual subjects for this EMMA.
The EMMA contains 3 'pages', called 'INPUT' (Basic data that should be entered to make EMMA functional), 'TABLES' (Spreadsheets used for entering target & actual progress percentages, man hours etc), and 'CHARTS' (Here accessed spreadsheets should be demonstrates as curves & histograms). The EMMA is applied for different purposes which are described below:
1. To arrange target rate of progress (S-curve);
2. To make an estimate regarding man-hours, converted to manpower requirements (histogram);
3. To register units computed as complete every month;
4. To register man-hours used each month, in that way automatically matching the actual rate of development and genuine handling of manpower, with premeditated rates.
5. Besides, unacceptable trends can thus be recognized and work re-scheduled, together with automatic adjustments to manpower requirements, that will lead achievement of target completion.
Primary needs for inputting are:
a. The projected total quantity;
b. Meaning of the unit (eg m3);
c. A valuation of man-hours necessary for each unit;
d. The average number of hours to be conducted each day;
e. The average number of days to be conducted on every week.
Subsequently, inputting should be compliant with notes provided.
Application of an EMMA will help in creating specific interest to anyone for taking liability to finish a work scope package before schedule.
6.11.B. Earthing tape, cable racks & trays, cables, terminations
The calculator demonstrated below can be employed for calculating man hours required for any one, or all, concerning the activities related to cabling which are incorporated. Besides, entering quantities, the user will be able to modify the unit manhour rates provided, for rates more in keeping with that User's environment.
To obtain a hypothetical example, click Real-time Sync, provide secret key 'electrified' and click connect.
To start calculation, click on the following link

Published By
Rajib Dey

Wednesday, September 6, 2017

RetainWall version 2.60 – A powerful software for designing a concrete or masonry retaining wall

Dhani Irwanto has developed RetainWall. It is an exclusive software that can be used for making the design of a concrete or masonry retaining wall. The wall may preserve soil or other granular material.
It examines the strength of the wall on the basis of the loads and resistances, and leads to bearing pressure, sliding, overturning and rotational stabilities. Loads which operate on the wall may include self weight, soil pressure, water pressure, live and seismic loads.

Resistances may contain base friction and cohesion, passive earth pressure, other structures or a shear key. Load and resistance factor design (LRFD) mode can be employed. If the wall is a reinforced concrete structure, the software can also produce the reinforcement design for any reinforced concrete structure wall. Besides, there is a soil pressure calculator.
This user-friendly application provides on-screen trial-and-error method and instant solution for the design. With it, any designer will be able to design the wall swiftly. Complete outputs are visible on screen or printed.
The software starts it’s operation by clicking on the specified dimensions to produce the initial dimensioning of the wall, earth surface and water levels. After that, it enters material properties of the wall, soil, water and reinforcement bars. Provided external loads contain surcharge load, seismic load as a horizontal seismic coefficient and any concentrated loads implemented on the wall if necessary. Load and resistance factors combinations are easily selected. Results of the wall stability are gained immediately. If satisfactory result is not obtained, then another trial can be produced instantly. You can also choose from options to use or not to use water, seismic or ashear key. The final results can also be printed.
The reinforced concrete design can be made instantly by applying the internal forces of the wall. It only needs bar diameters and spacings of the reinforcements.
RetainWall is compatible with metric, SI and British unit systems.
Given below, some exclusive features of the software :-
a. Ability to design Load and resistance factors.
b. Apply load and resistance factors combinations from AASHTO LRFD 2007, ACI 318-08 and IBC 2006.
c. Load and resistance factors editor to change or generate new combinations
d. Concrete reinforcement design from ACI 318-08.
e. Force diagrams (moment, shear and normal) for every combination.
f. Loads, resistances and reactions diagrams for every combination.
g. Wall stabilities (bearing, sliding, overturning, rotation) for every combination.
h. Workout nominal soil bearing resistance by applying theoretical or semi empirical methods.
i. Ability to select active or at rest soil pressures.
j. Ability to select elastic (rock) or plastic (soil) bearing pressures.
k. Ability to enter user's soil pressure coefficients.
l. Reinforcement design for upper stem, lower stem, toe and heel.
m. Unit systems, properties, load and resistance factors, reinforcement design method, and page setup from last editing which turn out to be the default for new design.
n. Ability to include other loads on wall.
o. Offer stability resistances from a shear key, toe passive soil pressure, adjacent structure, anchors or piles.
p. Enable or disable a shear key, water or seismic.
q. Various types of units of measurements like metric, SI and British unit systems are supported.
r. Easy, clear, quick and simple software operation.
s. Help facilities, can be printed to produce manual.

Click on the following link to download a trial version RetainWall version 2.60

RetainWall version 2.60 – A powerful software for designing a concrete or masonry retaining wall

Published By
Rajib Dey