Download Bar Bending Schedule Of Box Culvert

Definition of Bar bending

It is the method of bending reinforcing steel into shapes which are important for reinforced concrete construction.

Definition of Bar bending schedule(BBS)

Bar bending schedule alias schedule of bars refers to a list of reinforcement bars, a specified RCC work item that is shown in a tabular form for a smooth view. This table sums up all the necessary particulars of bars ranging from diameter, shape of bending, length of each bent and straight portions, angles of bending, total length of each bar, and number of each type of bar. This information can be used for making an estimate of quantities.

It includes all the details essential for fabrication of steel like bar mark, bar type and size, number of units, length of a bar, shape code, distance between stirrups (column, plinth, beam) etc.

While generating bar schedules, it is important to take proper care about length. In case of bending, bar length will be raised at the bending positions.

Benefits of the Bar Schedule:

When bar bending schedule is applied along with reinforcement detailed drawing, it makes the quality of construction superior.

Once bar bending schedule is prepared, cutting and bending of reinforcement is performed at factory and shipped to job site. This improves quick implementation at site and minimizes construction time and cost as fewer workers are needed for bar bending. Bar bending also circumvents the wastage of steel reinforcement (5 to 10%) and thus project cost is saved significantly.

It offers the perfect estimation of reinforcement steel requirement for all the structural members which are applied to workout complete reinforcement requirement for whole project.

Bar bending schedule offers the steel quantity requirement in a better way and thus delivers an option to make optimal use of the design in case of cost overflow.

The process becomes simple for site engineers to validate and approve the bar bending and cutting length throughout inspection prior to positioning of concrete with the support of bar bending schedule and thus facilitates in superior quality control.

It becomes easier to handle the reinforcement stock necessary for identified time duration.

It will facilitate to fabrication of R/F with structure.

To download the excel sheet for bar bending schedule, click on the following link 
Download Sheet

Read more

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Published By

Rajib Dey

www.constructioncost.co

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How does water play an important role in concrete?

In order to develop concrete, binding materials and inert materials are amalgamated with water. Therefore, the quality of concrete is dependent on the water and its quality as well as quantity. Water to cementitious materials ratio in concrete is most vital to ascertain the strength and longevity of concrete.

Water is essential to drench the surface of aggregates to form adhesive quality because the cement paste affixes instantly and suitably to the wet surface of the aggregates as compared to a dry surface. Also water plays a vital role to produce plastic mixture of the different components with the purpose of passing on workability to concrete so that it can be arranged in the preferred position. In due course, by making a chemical reaction with cement, water facilitates to form the desirable properties of the concrete.

Generally, consideration is not given to the quality of the water though water is very vital to detect the strength of the final product. It is a general conception that any potable water is ideal for being applied in concrete formation. But, if only non-potable water is usable, it is suggested to check the water to determine its contents and acquire necessary steps to provide possible adversarial effects on the final concrete.

Though water with little acidic nature is not harmful, but highly acidic or alkaline water must not be used as it may provide adversarial effect over the reinforcing of concrete. Water blended with algae should not be used as such water may lead to entrainments which sequentially can reduce the concrete strength. It is observed that sea water minimizes the long-lasting strength of the cement, though it is calculated to be just 15%. Water containing If, huge amount of chlorides are included in water, it results in creating perpetual dampness and surface efflorescence and also corrosion of steel utilized in concrete.

Thus, the available chemical components in water may actively form the chemical reactions and thus influence the setting, hardening and strength development of concrete. So, it is recommended to verify the quality of water in order to maintain the superior quality of concrete.

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Published By
Rajib Dey
www.constructioncost.co
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How To Resist Cracking In Fresh Concrete

Usually, the contractor should take responsibility with all essential steps to track and resist cracking in fresh hydrating concrete, devoid of the size or volume of the pour. The steps should be approved by the Engineer and ensure that extreme surface crack width on hardened concrete measure instantly after the pour does not surpass 0.004 times the nominal cover of the primary reinforcement.

The contractor will be responsible for and offer sanctioned instrumentation for measuring the variation of internal temperature in large pours. The extreme concrete temperature at the point of delivery usually shall not surpass the lower of either 37 degree C, or 6 degree C beyond the existing shade temperature compliant with the approvals of ACI. The limiting internal temperature differential measured over the maximum faces of concrete mass shall not go above 25 degrees C at any time.

Curing of hardened concrete will be done according to the curing specification. Usually, the element surface is not chilled to disperse heat from the concrete. Curing methods, like the drenching of heated concrete elements uncovered to long and direct radiation, which produce temperature gradients inside the concrete mass, are not recommended for application.

For big pours, the contractor will be liable for and take additional provisions to lessen concrete temperature gradient as well as check the loss of surface moisture. Such steps are described below :-

 Maintaining all mix ingredients shaded where feasible to decrease their temperatures in         the stockpile

 Chilling of mixing water and/or substituting part or entire of the extra water with ice.

 Lessening the cement content with the application of admixtures (but not lower that is           essential for the stability)

 Applying a cement having a inferior heat of hydration

 Injecting liquid nitrogen once the concrete is blended

 Limiting the time amid mixing and assigning of the concrete to below 2 hours

 Delivering permitted surface insulation constantly over all uncovered surfaces to resist           draughts as well as keep identical temperature with the concrete mass

 Starting curing instantly once final tamping is done and carry on till the permitted surface     insulation system is completely prepared

 Providing shade to the concrete surface to resist heat obtained from direct radiation.

For more information, click on this link

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Published By

Rajib Dey

www.constructioncost.co

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GRIDFORM™ Is An Advanced Concrete Reinforcing System For Vehicular Bridge Decks

GRIDFORM™ refers to a superior concrete-reinforcing system supported with prefabricated fiber reinforced polymer (FRP) double-layer grating and fundamental stay-in-place (SIP) form specifically designed for vehicular bridge decks.

This reinforcement system comprises of FRP plates glued to the bottom grating of FRP double-layer grating panels which produce a bidirectional, lightweight panel of the grid construction to be used with corrosion-free concrete bridge decks.

The lightweight GRIDFORM™ panel measures only 4.7 pounds per square foot. It is fabricated in shop with very big units which are restricted only by shipping constraints to around 50 ft. by 8 ft.

In the jobsite, the GRIDFORM™ is elevated through a single pick of a crane and directly set in the girders of the bridge. The GRIDFORM™ panel is pre-engineered and completed so that it can be affixed quickly to the bridge girders and relevant concrete placement and forming. The GRIDFORM™ bridge deck lasts long as compared to the steel reinforced concrete bridge decks as FRP delivers a corrosion-free reinforcement system for the concrete.

GRIDFORM™ Design Guide

The GRIDFORM™ Design Guide offers proper guidelines to structural engineers to define if GRIDFORM™ can be substituted for steel rebar as the internal reinforcement system for reinforced concrete bridge decks. Any engineering firm or installation contractor can utilize GRIDFORM™ by adhering to Strongwell's Terms and Conditions.

The GRIDFORM™ Design Guide is based on Microsoft® Excel® version 2003 or 2007.

• Download GRIDFORM™ Design Guide (Excel® 2003)
• Download GRIDFORM™ Design Guide User's Manual (PDF)

Ref : www.strongwell.com.

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Published By

Rajib Dey

www.constructioncost.co

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Detailed Process for effective slab reinforcement

This construction video will highlight the detailed process for complicated slab reinforcement. All steel bars are connected following the design details. Here the concrete ratio is 1:2:4. This video is very useful for Civil Engineering students as well as various structural engineering professionals.

The slabs containing ratio of longer length to its shorter length (Ly/Lx) larger than 2 is known as one way slab or else as two way slab. In one way slab main reinforcement is equivalent to shorter direction and the reinforcement equivalent to longer direction is defined as distribution steel. In two way slab main reinforcement is rendered alongside both direction.

Detailing Requirements of RCC Slab as per IS456: 2000

a) Nominal Cover:

For Mild exposure – 20 mm

For Moderate exposure – 30 mm

However, if the diameter of bar is less than 12 mm, or cover may be decreased to 5 mm. Therefore for core reinforcement up to 12 mm diameter bar and for mild exposure, the nominal cover will be 15 mm.

b) Minimum reinforcement: The reinforcement in either direction in slab must not be lower than

• 0.15% concerning the total cross sectional area for Fe-250 steel

• 0.12% concerning the total cross-sectional area for Fe-415 & Fe-500 steel.

c) Spacing of bars: The utmost spacing of bars must not surpass

• Main Steel – 3d or 300 mm whichever is lesser.

• Distribution steel –5d or 450 mm whichever is lesser Where, ‘d’ denotes the operative depth of slab. Note: The least clear spacing of bars must not be lower than 75 mm (Preferably 100 mm) even if code does not suggest any value.

d) Maximum diameter of bar: The maximum diameter of bar in slab, must not surpass D/8, where D denotes the total thickness of slab.

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Published By

Rajib Dey

www.quantity-takeoff.com

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construction programs to reduce their project costs significantly

Prototype constructions are gaining popularity among the governmental entities in the United States. Prototype construction refers to a construction program and the model of it is based on replication. In Prototype construction some prototype designs are created maintaining fundamental or crucial features which are approved for several structures. In this concept the design become identical through replication procedure. The design costs are reduced to a great extent due to onetime investment.

This method is ideal for architects, construction companies and engineering firms who strive to capture big public sector contracting opportunities in the United States.

The public officials are trimming down public project costs significantly through the Prototype construction.

Some applications of prototype constructions in USA

The state officials in Pennsylvania have planned to prototype construction to lessen the costs associated with the repairing works for structurally damaged bridges through the state’s Rapid Bridge Replacement Program.

To execute this program, a private-sector partner should be employed to facilitate finance, design and construction of 500 new bridges over a six-year period. Under a prototype construction project, the private-sector partner has to take the responsibilities for preserving the bridges for the state for up to 40 years.

The public-private partnership agreement facilitates saving money on design, construction and maintenance through a prototype for each bridge. The 500 bridges are same in size and design and hence one rendering will be applicable to each structure. Costs will be minimized as the replication process facilitates various types of economies of scale and shorter construction timelines.

In the same way, a private-sector firm has made a prototype design for the construction of all future U.S. embassies. The federal government can save huge amounts through utilization of the similar model and the similar building materials even as reducing construction timelines with best practices and experience.

School districts all through the country are going to undertake prototype building programs. Lots of school districts require new buildings at once due to the increased population. As soon as the design process for a structure is finished, construction work is cut down 10-14 months to about 4 which result in considerable savings.

In Florida’s Miami-Dade County, a prototype procedure is used to a dozen new schools which bring $9 million saving for the district.

In the Wake County schools of North Carolina, the prototype design results in saving between $1.9 million and $6.6 million on design fees. The DeKalb County School District in Georgia has applied a prototype design for reconstruction of seven elementary schools and in Rio Rancho, New Mexico, two new elementary schools were created from a prototype design.

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Published By

Rajib Dey

www.quantity-takeoff.com

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Apply cost index and market rate in estimate

BuildSystem web has a database of materials, manufacturers and their vendors for construction and maintenance of projects. Trusted name in construction cost data.

BuildSystem offers construction cost data products and services, cost estimating books, CDs and online services.

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Published By

Arka Roy

www.quantity-takeoff.com

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Importance of Concrete Estimating

The most used material in the architectural industry is concrete. No modern day construction can be completed without it. It can be customized to get compressive strength or color application, placed in almost any shape or form and finished to resemble masonry, stone and other surfaces. It is durable and virtually maintenance-free. This component is quite easy to work with and installs relatively quickly.

The segment concrete estimating specially deals the basic areas like: concrete materials and placement, formwork, reinforcing, finishing and pre-cast industry. The quantities of concrete usually estimate in measure of cubic yards, as this is how supply companies charge for it. Formwork is taken off in square feet (generally in square feet of area in contact with the concrete as opposed to the actual area of the forms used). Reinforcing is normally taken off in tons of steel. Finishing is taken off in square feet of finished surface. Pre-cast concrete quantities are taken off in either square feet or by the piece, depending on usage and the type of unit being considered.

Concrete estimating is quite an important issue to the estimators as the large amount of total cost is based on the cost of the concrete. That’s why it will be a great help to the estimator to know the probable cost of the total construction.


Posted By:
Debarati Nath
content Writer

Tips for concrete estimation

Estimating concrete reinforcing costs is a vital phase of a construction. For ascertaining this keep in mind that the reinforcing steel supplier has taken account of all accessories, cutting, bending, and allowances for lapping, splicing, and waste. When no lap specifications are mentioned add 10% to your quantities for lapping, splices, and waste. Also consider 10% waste for welded wire fabric.

Consider the labor unit price for the subdivision of Reinforcing to put in accessories like bean and slab bolsters, high chairs, bar ties and tie wire

Besides checking structural drawings and architectural drawing, also take into consideration the mechanical and electrical drawings for equipment pads and grouting requirements on steel drawings

Deduct small (two square feet or so) while making estimation of the concrete quantities for floor slabs or walls.

One can avail the concrete prices from suppliers near the job site. A volume discount is obtainable which depends on the competition in the area. Don’t forget to add for waste on the whole for slabs and footings on grade.

In the case of compression testing for a project consider a least amount of one test per pour on smaller pours and a smallest amount of one test for each fifty yards of concrete placed. Each test should comprise of a minimum set of three cylinders.

For structural concrete estimation, includes the requisites for concrete additives, curing methods and surface treatments. Also give consideration to climate conditions alongwith hot or cold weather conditions, prerequisites for concrete placing and finishing methods and equipment.

For estimating precisely the components like formwork, reinforcing steel, ready-mix concrete, placement of the concrete mix, finishing of the surface, and curing should also be considered.


In order to finish the concrete surface a good rule of thumb for finishing concrete permits 1,000 S.F. of slab per each cement finisher.

Posted by Rajib Dey
Business Development
rajib@jobs2india.com
The estimating Service

SHOP DRAWING creates maximum benefits for construction companies

The shop drawing is a drawing or collection of set of drawings, diagrams, illustrations, schedules, and other data or information specifically generated or assembled by the contractor, supplier, manufacturer, subcontractor, or fabricator to demonstrate some portion of the work for the approval of architect or engineer.

Unless this task is specifically delineated in a governing agreement, design professionals and engineers should not generate shop drawings, especially in areas relating to the means and methods of construction.

The shop drawing is a graphic or written description of the work drawn to provide the information on behalf of manufacturer or the contractor to describe the fabrication, installation of the items to the manufacturer’s production crew or contractor's installation crews. The information is shown in construction documents.

Within the steel industry a majority of fabricators and detailers prepare shop drawings for pre-fabricated components. This type of components include elevators, structural steel, trusses, pre-cast, windows, appliances, cabinets, air handling units, and millwork.

With the help of shop drawing the steel fabricator gets the ability to fabricate each piece of steel in the building. Shop drawings contain brief information relating to material specifications, sizes, dimensions, welding, bolting, surface preparation, painting requirements, etc.

In a construction project, the number of shop drawings surpasses the number of construction drawings. It is observed that approximately 70 to 80 construction drawings versus 1,000 shop drawings are required in the case of documenting the steel frame for 1,000-ton building (1,000 tons of steel).

As soon as the shop drawings are completed, the mill order can be submitted sooner, the fabrication will be started immediately and the steel can be erected sooner

Concrete reinforcing is another segment in which the shop drawing is required by reinforcing steel fabricators for fabrication of the material. Here the shop drawing is prepared to lists the quantity, sizes, lengths, and shapes of the reinforcing bar. The structural engineers review this information to make sure that sufficient reinforcing is being supplied to be organized for storage and installation.

MEP Engineers also prepare installation and coordination shop drawings for sheet metal ductwork, piping, plumbing, fire protection, and electrical. Shop drawings are not produced by architects and engineers under their contract with the owner.

In brief shop drawings can be explained as below:-
• Comparison information for the architect and engineer
• Notes of changes or alterations from the construction documents
• Information required fabricating the product
• Indication of dimensions needing verification from the jobsite
• Placement or installation information
• Samples

Now a days the drafting software(CAD), 3D steel detailing software and building information modeling software(BIM) are utilized for creation & digital review of the shop drawings in which the multiple copies of each fabricated piece drawing will be reviewed electronically eliminating the paperwork that would total approximately 30,000 sheets of drawings for a construction project.

Rajib Dey
Construction Estimating Service