Layout of plot at construction site

From this civil engineering video tutorial, we will get some useful guidelines about how to create layout for any type of plot at construction site as well as details about grid layout drawing.

Gridlines belong to the labeling marks of a floor plan. For drafting the plan of a large area, these labeling marks will allow the plans to be placed in separate sheets and the grid lines will demonstrate the connection of the two framing plans. With grid lines, it becomes easier to recognize specific locations on the floor plan for any structural member in the floor plan.

As for instance, for a Column at grid A, this should be the first column location at Grid line A and Grid line B.

These generally stands for the letters from A to Z, etc, around the vertical direction; and letters 1 to 2, etc around the horizontal direction; that species the identity of one certain position of a structural member on the floor plan.

Grid lines are mostly provided in construction drawings alias working drawings. They play an important role throughout the setting out process on site. Each grid line gets across a wall or a column for that matter.

Spacing among one grid line to the other. points out the distance to exclude while arranging the walls and columns on site.

Each grid contains a marking. It is generally recommended to mark them both numerically and alphabetically omitting the number '0' and alphabets 'O and I' as these may become problematic for the reader to distinguish sometimes. When the contractor requires any modification on some column on site in case the engineer is not present, the contractor can give a call and easily identify the disputable column.

The use of grid lines is standard on any construction drawings.

For online demonstration, go through the following video tutorial.



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Published By
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www.constructioncost.co
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Types of water tank & the height calculation of tank

On the basis of material types and location, the water tank is categorized as follow :-

Chemical contact tank – This type of water tank is formed with polyethylene construction and prepared for retention time of chemical treatment.

Ground water tank – It is formed with lined carbon steel. The water is delivered through a water well or from surface water. A huge quantity of water is arranged in inventory and utilized throughout high demand cycles.

Elevated Water Tank – This type of water tank is also called water tower. It will produce pressure at the ground level outlet containing 1 psi per 2.31 feet of elevation. Thus, a tank that is raised to 70 feet develops about 30 psi of discharge pressure. 30 psi is ideal for most domestic and industrial requirements.

Vertical cylindrical dome top – This type of tank may reserve fifty gallons to various million gallons. These types of tanks are suitable for transport as their low-profile produces a low center of gravity facilitating to sustain equilibrium for the transport vehicle, trailer or truck.

A hydro-pneumatic tank – This type of tank generally refers to a horizontal pressurized storage tank. By pressurizing this reservoir of water, a surge free delivery of accumulated water can be provided to the distribution system.

On the basis of the shapes, the water tank is categorized as follow :-

Circular Tanks – They are most cost-effective and utilized in greater capacity for delivering water, sewerage treatment etc.

Rectangular Tanks – These types of tanks are utilized for small storage capacity and their construction process is expensive.

Spherical Tanks – These types of tanks are utilized for the cost-cutting measure and aesthetic view point.

Intze Tanks – They are suitable for greater storage capacity. In these types of tanks, domes are utilized as a substitute for level slabs.

How to find out the maximum daily demand necessary for the population of the locality?

Target Population = 1500
Maximum daily consumption
= 180% of average daily demand = 1.8 x q
The demand of water for domestic purpose = 200 lit / capita / day
Average daily requirement (q) = Per demand x Population
= 200 x 1500 = 3,00,000 lit / day
So, maximum daily demand = 1.8 x q litres / day
= 1.8 x 3,00,000 litres / day
= 540 x 103 litres / day
= 540 m3 / day

How to find out the complete height of the tank?

Suppose, the diameter of tank (D) = 12m (<30m)
Therefore, radius of tank (R) = 12/2 = 6m
Now, the volume of tank = 540 m3
The height of the cylindrical tank is taken as h
So, the capacity of tank = π x R2 x h

After deducting the values, we get the following :-

π x 62 x h = 540
or, h = 540 / (π x 36)
or, h = 4.77
So, the height of the cylindrical tank = 4.77 m
Suppose, free boarding = 0.25 m
Therefore, the total height of the tank = (4.77 + 0.25) = 5.02 m = 5 m (approx)

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Published By

Rajib Dey

www.constructioncost.co

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Foundation problems & causes of cracks

Foundation problems are great concerns for majority of houses. The foundation problems occur due to several reasons like concrete shrinking, settling of soil, construction flaws, irregular soil, ground pressures, water pressure and lots other.

When the foundation problem is extreme, the structure will be significantly damaged. The following factors are the indication of foundation problem :-

Cracks in wall, floor and ceiling
Irregular or sloping floors
Bowed walls or floors
Doors and windows are not opened or closes perfectly
Doors, windows and garage doors getting detached from the adjacent walls
Spaces among walls and ceilings
Spaces among walls and floors
Leaks and cracks in and around the fireplace
Tilting Chimneys

Types of cracks in foundation

Vertical cracks

Vertical cracks in masonry among two structures occur due to differential settlement or thermal settlement.

Vertical cracks in masonry walls or mortar joints occur because of shrinkage or thermal movement. When the cracks remain uniform in width, irregular or straight there is less risk since these cracks are easily repairable with a professional grade crack repair kit.

Vertical cracks in poured concrete happen owing to shrinkage or thermal movement. If the cracks are uniform in width, irregular or straight there is less risk since these cracks are easily repairable with a professional grade crack repair kit.

Cracks in brick either straight or stepped specifically adjacent to the ends of wall, frequently occur because of expansion or thermal movement. When the bond courses in wall are shattered, there is possibility for collapsing of the building.

In wall, larger at bottom rather more at top – settlement under building, these cracks in masonry block wall are less harmful as compared to horizontal cracks. But these cracks are great concern when discovered in a brick wall specifically when bond courses are broken and there is possibility for collapsing.

Diagonal cracks

Diagonal cracks occur because of various reasons like frost heaves, frost lensing, shallow footing, water problems, insufficient backfill, foundation settlement, extensive clay soil, damage by a shrub/tree adjacent to the foundation wall. Most of the time, the diagonal cracks are repaired with a professional-grade crack repair (poured foundations). If there is a series of small diagonal cracks which can be extended abruptly, they can create more serious issue like sink holes, imperfect loading/header defect.

Horizontal Cracks

The horizontal cracks occur because of the following reasons :-

When the crack is situated high on the foundation wall, it is mainly occurred for cold climates or vehicle loading.

When the crack is situated mid-wall on the foundation, it is occurred because of probable vehicle loading, backfill damage or earth loading.

When the crack is situated low on the foundation wall, it is happened because of earth loading.

Most hairline cracks resulting from shrinkage on a poured foundation wall, can be resolved with a crack repair. Other cracks like large cracks or cracks in brick foundations should be repaired with the help of a professional.

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Published By

Rajib Dey

www.constructioncost.co

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How to measure the volume of silt content in sand

In this civil engineering video tutorial, you will learn some vital tips to work out silt percentage in sand or course sand to ensure that whether the sand is eligible to be used in concrete or not. It is recommended that the percentage of silt content of sand in concrete should be over 6%.

The silt stands for a very fine particle and the size of it is under 150 Microns. Silt content can be shrinked and inflated because of the weather condition. Therefore, it can impact the strength of the structure.

Impacts of Silt:

1. Crack will be created on concrete. (some cracks are found in the wall)
2. Silt content includes evaporated matters and salts. (mortar will be exposed at the time of plastering)
3. It engrosses more water. (broadened & shrink owing to the weather condition.

To determine the percentage of silt conent, the following items will be required :-

a. 250 ml, measuring cylinder
b. Course or fine sand
c. Water
d. Sand

The calculation is done as follow - Initially, it is required to area of cylinder as the cross sectional area from top to bottom will be same for the cylinder.

Area of cylinder = πr2 x Height

Suppose, the cylinder is filled with sand up to 100 ml, then water is added up to 50 ml. So, total volume will be 150 ml. Then, shake the bottle and wait for 2 hours. Now, it is found that the percentage of silt content in the sand is 5 ml. You can check the percentage of silt content in the following way :-

= Volume of silt (taken as V2) / Volume of sample (sand or course sand; taken as V1) x 100
= 5 / 100 x 100 = 5%

To get more information, watch the following video tutorial.

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Deductions for openings in masonry

The following types of deductions are commonly found in masonry constructions.

Rectangular Openings

For rectangular openings full deduction will be as follow :-

Deduction = Length x Height x Thickness of wall

Segmental Arch Openings

With the existence of segmental arch opening over the rectangular opening, deduction in masonry is provided for both the rectangular opening & the segmental arch opening.

Area of rectangular part = L x H
Area of segmental part = 2/3L x R x R3 /2L

So, the total deduction is as follow :-

[L x H + 2/3L x R] x thickness of wall

Semi-circular arch opening :

Semi-circular arch opening :
Area of semi-circular portion = πR2/2

But the approximate area of the semi circular section is as follow :-

= ¾ L x R
So, the total deduction
= [L x H + ¾ L x R] x thickness of wall

Masonry of arch

The quantity of masonry in arch is calculated with cubic meter as an individual thing.

The quantity of arch masonry is subtracted from the total masonry.

Masonry of arch 
= Centre length of arch x width of the arch x thickness of arch
So, the deduction for arch in masonry
= Lm x b x t

Lintel over opening

An RCC lintel is constructed over the door or window opening.

The quantity of RCC of lintel is subtracted from the masonry work.

A bearing of 10 to 15 cm from the edge of opening is arranged to the lintel on either end of the opening. So,

Length of lintel (L) = Span of opening + 2 x bearing deduction for lintel = L x Width of wall x thickness of lintel.

Area of semi-circular portion = πR2/2

But the approximate area of the semi circular section is as follow :-

= ¾ L x R So, the total deduction 
= [L x H + ¾ L x R] x thickness of wall

Masonry of arch

The quantity of masonry in arch is calculated with cubic meter as an individual thing.

The quantity of arch masonry is subtracted from the total masonry.

Masonry of arch

= Centre length of arch x width of the arch x thickness of arch
So, the deduction for arch in masonry
= Lm x b x t

Lintel over opening

An RCC lintel is constructed over the door or window opening.

The quantity of RCC of lintel is subtracted from the masonry work.

A bearing of 10 to 15 cm from the edge of opening is arranged to the lintel on either end of the opening. So,

Length of lintel (L) = Span of opening + 2 x bearing deduction for lintel = L x Width of wall x thickness of lintel.

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Top ten software for estimating and bidding

Sage Estimating

Sage Estimating can significantly accelerate the estimating process for several construction firms. Sage facilitates you to produce bids rapidly, precisely and positively with takeoff and cost databases. As soon as the project is procured, estimate details flow automatically into Sage business management software, removing unnecessary tasks and data entry errors. Sage Estimating also facilitates forecasting the labor, raw material and other overhead costs so that the contractors can arrange & deliver correct bids.

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Candy

It is a superb Construction Project Management Software to manage projects efficiently in the construction & engineering industry. It focuses on the need of the contractor ranging from quantity take-off, pricing and planning a project, controlling at the site level, analytical calculations, critical path planning, dynamic forecasting, Project cash flow through to the final certificate. Candy maintains an interactive link among the Bill of Quantity (BOQ) and the construction program or schedule of work under one construction project management solution.

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B2W Estimate

B2W Estimate is useful for heavy civil construction estimating and bidding. The software can generate and pre-populate comprehensive databases with costs along with default templates of crews and pay items. Estimators will be able to perform by accessing the resources and items even when the server is offline. Just reconnect, and the new estimates or alterations are included on the server. So, it becomes possible for the companies to work from any remote location or download a bid locally for closing throughout bid day.

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HCSS Heavy bid

This software facilitates the users to create estimates and control regular bids. The software can computerize repetitious tasks on the basis of tracking data from various sources like past estimates, standardized libraries, historical costs, performance data, and integrated RSMeans. Users will be able to form, review and edit estimates instantly as well as make automatically run price calculations to recognize errors. HeavyBid empowers the users to decompose complicated work into more controllable pieces, and arrange estimates to meet the requirements of the organization. Users can also evaluate subcontractor and supplier quotes.

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CostX

CostX can instantly capture exact measurements from scanned, PDF and CAD drawings together with formation of automatic BIM quantities from 3D/BIM models. The live-linked hierarchical workbooks can be applied to make an estimating build up with links to user-defined rate libraries. Besides, customized reports can also be generated.

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Stack

Stack can generate bids with user-defined pricing so that it becomes easier to work out the costs more precisely. The users can perform their own takeoffs within the program, or send request to the STACK team to accomplish the work for them with a single click through the STACK To-Go tool. STACK Estimating also offers pre-built catalogs for some trades with comprehensive lists of equipment, labor, and materials which are necessary for the users depending on adjustable historical experience.

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ProEst Estimating software

It is a cloud-based construction estimating software with automated features for different types of construction companies. It allows the construction teams to check and control centralized estimates, takeoffs, reports and contracts, and all information can be obtained and distributed 24/7 from any mobile device with active internet connection. Users can compute, analyze and manage business performance during the project lifecycle, and construction databases offer current costing and productivity data. ProEst can also track pending projects, upgrade estimate pipelines and make perfect short- and long-term business forecasts.

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eSub

eSUB makes paperless projects providing one central storage for project information, photos, drawings, PDFs and any other documents that all team members can access practically. By logging in via a protected internet portal, eSUB’s project management module facilitates the subcontractors to produce, log, and track vital documents like requests for information (RFIs), change orders, and more. eSUB’s timecard module tracks subcontractors’ labor hours and costs, which can be delivered from the job site to accounting software. Get rid of tracking projects manually and automates labortracking and communication.

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Clear Estimates

It is a cloud-based construction estimating system useful for remodelers and contractors to make estimates, submit bid requests, draft proposals, manage customers and more. The system is adjusted to satisfy the requirements of most trades like homebuilders, design/build firms, finishing contractors, roofing and siding contractors and other speciality contractors. It is helpful for smaller companies that creates less than $5 million in revenue annually.

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On-Screen Takeoff

On-Screen Takeoff can produce and finish more bids correctly. There are various tools for estimating, managing bids and maintaining project visibility. A bid wizard assists the new users through all dialogues at the time of generating a new bid. The application supports digitizer integration, file integration (CAD, PDF, etc), and 2D takeoff. The estimating application comprises of electronic quote system, cost databases by trade, and accounting integration. The system is well matched with tablet technology that allows the users to access project data in the jobsite for cost and labor management.

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Published By
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www.constructioncost.co
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Calculation of the quantities cement, sand & water in mortar for any brickwork

In this civil engineering video tutorial, you will learn how to work out the quantities of cement, sand and water in the mortar of any brickwork construction. Also learn how to calculate wastage.

The volume of mortar in a brick wall can be calculated as follow :-

Volume of brick wall = total volume of all bricks + volume of mortar

So, volume of mortar = Volume of brick wall – total volume of all bricks except mortar

The calculation is done in the following ways :

Total volume of bricks with mortar is taken as 10 cubic meter

The thickness of mortar is considered as 10 mm

The proportion of cement and sand = 1:6

The size of each brick = 190 mm x 90 mm x 90 mm

The size of brick with mortar = 200 mm x 100 mm x 100 mm (after adding 10 mm mortar thickness)

Volume of each brick along with mortar = Length x Breadth x Height = 0.2 x 0.1 x 0.1 = 0.002 cum (here, each is divided with 1000)

So, total numbers of bricks in 10 cum = 10 / 0.002 = 5000

The volume of each brick except mortar = 0.19 x 0.09 x 0.09 = 0.001539 cum

The volume required for 5000 numbers of bricks = 0.001539 x 5000 = 7.695 cum

So, volume of mortar = Volume of total brick work with mortar – Volume of total bricks = 10 – 7.695 = 2.305 cum (wet volume)

Because of frog filling, brick joint filling as well as wastage, the quantity is raised by 15%.

So, the volume of wet mortar = 2.305 + (15% of 2.305) = 2.651 cum or cubic meter.

To covert wet mortar to dry mortar add 33% as follow :-

Volume of dry mortar = 2.651 + (33% of 2.651) = 3.526 cum

The quantities of cement, sand and water will be calculated as follow :-

Cement = Volume of dry mortar x ratio of cement / sum of ratio x density of cement = 3.526 x 1/7 x 1440 = 725.348 = 14.51 bags (sum of ratio = 1+6 = 7)

Sand = Volume of dry mortar x ratio of sand / sum of ratio x 35.3147 (1 cum = 35.3147 cft) = 3.526 x 6/7 x 35.3147 = 107 cft or cubic feet

Suppose, the ratio of water and cement = 0.45

So, water / cement = 0.45

Water = 0.45 x cement = 0.45 x 725.348 = 326 litres.

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Some vital characteristics of concrete in fresh and hardened state

STRENGTH:

Concrete has good strength against compression but poor strength against tension and bending as a result the concrete can’t be demolished easily but with little force, it can be separated into pieces or leads to bending cracks.

Compressive strength is mainly based on the amount of cement utilized, but it is also influenced by the ratio of water to cement along with proper mixing and placing, and the capacity and extent of hydration and curing.

Both tensile strength and flexural bending strength will be raised with inclusion of steel or fiber reinforcement.

Desired compressive strength is based on an analysis of the loads that will be applied and the soil conditions at the project site.

DURABILITY

Concrete that will be walked or driven on should have good resistance capacity against abrasion in order that it doesn’t corrode.

Concrete that is uncovered to the exterior of a building should contain strong resistance capacity against weather in order that it doesn’t weaken from frequent freezing and thawing.

The stability of concrete uncovered to frequent freeze-thaw cycles is considerably raised with air entrainment.

Concrete in which steel reinforcement is implanted should control extra moisture absorption with the purpose of safeguarding the metal from corrosion.

VOLUME STABILITY:

As a porous material, the concrete is widened and compacted with variations in temperature and moisture content. Preliminary shrinkage occurs to cement-based products like concrete, concrete masonry and stucco since the cement hydrates and additional mixing water evaporates.

Additional shrinkage in concrete leads to cracking and consequently facilitate the moisture to infiltrate, and a vicious cycle of corrosion will start.

Shrinkage cracking is controlled moderately with steel or fiber reinforcement, and the position and weather resistance of shrinkage cracks can also be controlled via control joints which segregate the concrete into smaller panels or sections.

The shrinkage cracking may also be affected with the mix design and ingredient proportions.

WORKABILITY:

The workability of fresh concrete becomes superior when it is formed, compacted, and finished to its final shape and texture with nominal attempt and devoid of segregation of the materials.

Due to poor workability, the concrete fails to flow smoothly into forms and correctly envelop reinforcing steel and embedded items, and it becomes complicated to compact and finish.

Every mix should be perfect for its proposed application, maintaining a balance between desired fluidity, strength, and economy.

Workability is associated with the stability and cohesiveness of the mix, and is influenced by the cement content, aggregates, water content, and admixtures.

CONSISTENCY:

Consistency is an attribute of workability concerning the flow characteristics of fresh concrete.

It is the evidence of the fluidity or wetness of a mix and is calculated with the slump test. Fresh concrete is set in a metal cone and after detaching the cone, the concrete slumps a certain amount based on fluidity. A wet, soft mix slumps in a greater extent as compared to a drier, stiffer one.

A high-slump mix leads to extra bleeding, shrinkage, cracking, and dusting of the hardened concrete surface.

A specific range of consistency exists that is ideal for each type of work. Workability is highest in concrete having medium consistency with a slump among 3 and 6 in. The functionality of both very dry (low-slump) and very wet (high-slump) mixes is reduced.

COHESIVENESS:

Cohesiveness refers to the component of workability to identify whether a mix is harsh, sticky, or plastic.

A harsh mix does not have plasticity and the elements may have a propensity to detach.

Harshness occurs due to extra or shortage of mixing water (high- or low-slump mixes), a shortage of cement (lean mixes), or fine aggregate particles.

Harshness may also occur because of extra rough, angular, flat, or elongated aggregate particles. Harsh mixes are improved with air entrainment or by enhancing the fine aggregate or cement content, but modifications should be done to the overall mix to sustain the exact proportion of all materials.

A sticky mix may contain higher cement content (fat mixes) or large amounts of rock dust, fine sand, or similar fine materials (over-sanded mixes). Sticky mixes are not detached easily, but as they need a lot of water to attain nominal workability, sticky mixes may frequently contribute to extra shrinkage cracking.

A plastic mix is cohesive without becoming either sticky or harsh, and the materials can be easily detached until the concrete is managed incorrectly.

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