Friday, December 30, 2016
Bar bending schedule offers the reinforcement calculation for reinforced concrete beam. It supplies details of reinforcement cutting length, type of bends and bend length.
Here we will take one example for reinforcement quantity calculations for a concrete beam.
Example of RCC Beam Reinforcement Calculation:
Assume a beam of clear length of 4m, 300mm wide by 450mm depth. It consists of 2-12 diameter bars at top, and 2-16 diameter and 1 – 12 diameter bars at the bottom. Diameter of stirrup is 8mm spaced at 180mm center to center. Clear cover to reinforcement provided is 40mm.
Now we will calculate the length of reinforcement on the basis of shapes of reinforcement mandatory for reinforced concrete beam in above example.
We will start with bottom reinforcement, B1.
Bar shape of B1 is as shown below:
RCC Beam Bar Bending Shape
Length of B1 = clear distance between walls + 2 x width of walls – 2 x bar cover + 2 x bend length
Bend length = 6 x 16 = 96 consider as 100mm
Bend length is calculated as 6 x diameter of bar for reinforcement conforming to IS: 1786-1961
Length of B1 = 4000 + 2 x 230 – 2 x 40 + 2 x100 = 4580mm
Length of bar B2 is calculated on the basis of the shape of this bar. This bar bends up closer to the support as shown below:
RCC Beam Bar Bending Shape
Length of bar B2: A + B + C = 4000 + 2 x 230 – 2 x 40 + (1.414xH – H)
H = 450 – 2 x 40 – 2 x 12 – 2 x 12/2 = 334mm
B2 = 4000 + 2 x 230 – 2 x 40 + (1.414×334 – 334) = 4518.3 = 4520mm
Length of Bar T1 = 4000 + 2 x 230 -2 x 40 = 4380mm
Length of Stirrups S1:
RCC Beam Stirrups Length Calculation
Stirrups are spaced at 180mm center to center. Stirrups are provided between walls or support for a beam.
No. of stirrups required for given beam = No. of Stirrups
Length a = 450 – 2 x40 – 8 = 362mm
Length b = 300 – 2 x 40 – 8 = 212mm
Therefore length of 1 stirrup S1 = 2 x (212 + 362 + 90) = 1328 mm
Where 90mm is the minimum hook length as per IS 2502 – Table – II.
Wednesday, December 28, 2016
This example problem of a Concrete Slab Formwork design using an excel spreadsheet is very handy for all construction professionals out there.
This tutorial shows how to configure a spreadsheet with the purpose of design the spacing of joists, stringers and shores for a concrete slab form.
In this tutorial you will learn a step by step guidance delivered by matt hallowell. Enjoy the tutorial below:
Tuesday, December 27, 2016
In the sector of civil engineering, quantity surveying plays an important role. The professional person who is involved with construction cost and contracts of construction industry is called quantity surveyor.
Services offered by a quantity surveyor may consist of:
- Value engineering
- Risk management and calculation
- Tender analysis and agreement of the contract sum
- Commercial management and contract administration
- Assistance in dispute resolution
- Asset capitalization
- Cost management process
In this tutorial you will learn a step by step guidance on quantity surveying delivered by Xpacademy.com. Enjoy the tutorial below:
Monday, December 26, 2016
The slope deflection method is a structural analysis method for beams and frames . Before the development of the moment distribution method, the slope deflection procedure was widely used more than a decade.
In this lecture you will learn the analysis of indeterminate frames step by step (with proper equations and diagrams) by the help of the use of the slope-deflection method.
Enjoy the tutorial below:
Thursday, December 22, 2016
This construction video provides brief demonstration on cost estimator, an exclusive tool for precise construction cost estimation. This construction tool can work out the costs perfectly for any home building project. This tool will provide spreadsheet based three diverse estimates concurrently. So, it is not possible for you to view the discrepancies while obtaining each new estimate.
This estimating tool creates estimate on different phases which range from Preconstruction, site work, concrete stone brickwork, footing and foundation, subcontractors (wide list of probable subcontractors drywallers, painting, roofing and framing), miscellaneous like decks & outbuilding, custom built-ins, appliances, and contingency amount.
Wednesday, December 21, 2016
On the basis of the capability of the cement to be set in the existence of water, cements used in construction are classified as either hydraulic or non-hydraulic (see hydraulic and non-hydraulic lime plaster).
It will be difficult for non-hydraulic cement, to be set in wet conditions or underwater; instead, it sets once it dries and reacts with carbon dioxide in the air. It is defiant to any chemical attack as soon as it is set.
Density of Cement = 1440kg/m3
For 1 m3 Cement needed is 1440 kg
1 Bag of Cement = 50 kg
For 1 m3 Cement needed = 1440/50 = 28.8 bags
We know, 1 m3 = 35.3147 CFT
Or, 28.8 bags = 35.3147 CFT
Or, 1 Bag = 35.3147/28.8 = 1.226 CFT
Wednesday, December 7, 2016
Formwork alias bekesting / mal / molds that is formed with wood, plywood, steel to develop the fresh concrete.
TRIO stands for the globally recognized formwork system for all applications where the primary objective is to minimize the times for shuttering by applying traditional DW tie technology. With the BFD coupler for virtually all connections and many other practical system solutions, TRIO has proved it’s worth in numerous projects all through the globe. TRIO is utilized simultaneously with the more innovative MAXIMO panel formwork. A wide array of accessories, like the BFD Coupler or MXK Bracket System, is applied in both systems.
Given below, some exclusive features of Trio
- Panel formwork is very flexible for faster performance. Panel formwork supports MAXIMO panel formwork
- Panel heights up to 3.30 m, panel widths up to 2.40 m (standard system)
- Highest allowable fresh concrete pressure: 80 kN/m²
- Compatible with DW 15 and DW 20 tie systems
- Flush, aligned and firm connections with the BFD Alignment Coupler – along with filler timber compensations up to 10 cm
- Easy cleaning operations because of the powder-coated frame
Monday, December 5, 2016
Footings are crucial part of foundation development. Footings are generally formed with concrete through rebar reinforcement that is poured into an excavated trench. The footings are developed to provide support to the foundation and avoid settling.
A footing is a foundation unit that is built in brick work, masonry or concrete supported with the base of a wall or a column with the aim of dispersing the load over a huge area. A footing or a shallow foundation is arranged immediately underneath the bottom most part of the Superstructure supported by it.
A combined footing stands for a long footing that supports two or more columns in (generally two) one row. A combined footing belongs to a rectangular or trapezoidal shaped footing.
Download the sample drawing of combined footing design.
Saturday, December 3, 2016
By watching this construction video tutorial, one can sharpen his/her knowledge for developing stairs. The video also provides detailed information on how to measure the individual riser height by separating it into the total height among the lower and upper floors as well as estimate individual part perfectly.
While developing stairs, focus should be given on proper layout and some theoretically delicate calculations. Stairs must adhere to stringent building codes to maintain proper safety and climbing comfort.
There are three prime components in a standard staircase like stringers, treads and risers. Stringers, generally cut from 2 x 12s, which belong to the sloped boards for providing support to the other components and bearing the weight of people walking on the stairs. They're usually arranged 16 in. on center. While defining the width of the staircase, wider width is preferred as people can wal on wide staircases securely and comfortably.
Treads build the top surface of every step, and risers are set up directly below the front lip of each tread. Some stairs don't contain risers but it should be avoided as risers safeguard the uncovered endgrain of the notched stringers from the weather.
Friday, December 2, 2016
Concrete – cement : sand : gravel is a proportions calculator that measures perfect ratios and volumes of cement, water, sand and gravel in litres for producing concrete mix of the needed strength (mark).
The users will be able to indicate the density of the concrete mix, components humidity, porosity of sand & gravel and the requirement for smoothing down the completed structure as well as maintaining the correctness of calculation.
In case you are unaware about them, just keep the default values. Alternatively, you can choose the question symbol to work out, how the measurements will be completed.
The application is specifically developed for the builders who prepare concrete in a mixer independently.
Touch the question symbol if something is uncertain.
Go through the following link to download this useful construction app
Thursday, December 1, 2016
This construction video provides step-by-step instructions on how to measure excavation and backfill concerning trenches.
Trench stands for an extended excavation that is separated from pits or basements. A footing is a good instance of the trench.
In order to find out the volume of excavation for a simple footing, the following formula is used :-
CL x W x D = Cu.Ft. of Excavation
If you want to change to cubic yards, divide the results by 27
It becomes very difficult while going to make calculation for a trench that includes working spaces and sloped sides. The following formula is used for this purpose.
CL x AD x AW = Cu.Ft. of Excavation